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Advanced Manufacturing Processes (AMPs) Short-term Course on Manufacturing 4.0 By Dr. Pankaj Chhabra Director Edu-Crafter Academy
• Aims • To provide and insight on advanced manufacturing processes • To provide details on why we need AMP and its characteristics • Topics Covered • Introduction and requirement of AMPs • Classification of AMPs • HMPs • Classification of HMPs • Various important types of AMPs
Materials Used In Engineering Applications Plastics and Composites Ceramics HOW TO MACHINE THEM ? SOLUTION • Getting More Popularity • Definite Advantages Over Others Engineering Materials Having Much Superior Properties • Ultra High Strength, Hardness Very High Temperature Resistance • Difficult To Machine By Conventional Machining Methods Metal and its Alloys Advanced Manufacturing/Machining Processes
Need of Advanced Manufacturing/Machining Processes • Limitations of conventional machining methods (workpiece hardness, surface roughness, 3-d parts and complex geometries) Increased Workpiece Hardness Decreased Economic Cutting Speed Lower Productivity • Rapid Improvements In The Properties Of Materials (Workpiece Hardness, Strength, Etc.) • Metals & Non – Metals : Stainless Steel , High Strength Temperature Resistant(hsrt) Super Alloys: Stellite, Incoloys Etc. • Tool Material Hardness >> Workpiece Hardness  Requires Much Superior Quality Of Tool Materials
Product Requirements  Complex Shapes  Machining In Inaccessible Areas  Low Tolerances (Say,10 µm)  Better Surface Integrity (No Surface Defects, Etc.)  High Surface Finish (Nano Level Ra Value =>Nm)  Miniaturization Of Products (Examples: Landline Phone & Mobile, Old Computers & Lap Top, Etc.)  High Mrr Need Of Advanced Manufacturing/ Machining Processes ?? High Production Rate While Processing Difficult –To- Machine Materials Low Cost Of Production Precision And Ultra precision Machining (Nano-meter Machining) Requires Material Removal In The Form Of Atoms And / Or Molecules ADVANCED MACHINING PROCESSES (Amps)
Behaviour and Manufacturing Properties of Engineering Materials Structure of Material Physical and Chemical Properties Mechanical Properties Property Modification  Atomic Bond: Metallic, Ionic, Covalent  Crystalline  Amorphous or Non-Crystalline  Partly Crystalline  Polymer Chains  Melting Point  Density  Specific Heat  Thermal Conductivity  Thermal Expansion  Electrical Conductivity  Magnetic Properties  Oxidation  Corrosion Strength  Ductility  Elasticity  Stiffness  Hardness  Toughness  Fatigue  Creep Resistance to Wear, Corrosion, Oxidation  Hot Hardness and Strength  Heat Treatment  Annealing  Tempering  Normalizing  Hardening  Alloying  Reinforcement s  Composites  Laminations  Fillers  Surface Treatment
[1] CLASSIFICATION OF VARIOUS MANUFACTURING PROCESSES Basic Nature Traditional or Conventional Processes Advanced or Unconventional Processes Primary Forming Processes [Additive Or Accretion: Create Shape From Molten, Gaseous, or Solid Particles] Casting and Molding Processes Rapid Prototyping Processes [After 1990] Single-Use or Expendable Mold Casting Multiple-Use Mold Casting Liquid Based Solid Based Powder Based Multiple-use Pattern Single-use Pattern Permanent Mold Casting: Slush casting, Corthias Casting Low- pressure Vacuum Casting Die Casting, Squeeze Casting, Centrifugal Casting, Semicentrifugal Casting Centrifuging Casting, Continuous Casting, Electromagnetic Or Levitation Casting SLA, SLT, SGC, SOUP, SCS, etc. FDM, LOM, MJM, SAHP, etc. SLS, BPM, TDP , MJS, DSPC, etc. Sand Casting, Plaster Mold Casting, Ceramic Mold Casting, Rubber Mold Casting, Graphite Mold Casting, Shell Molding, Investment Casting, Full-mold and Lost- Foam Casting For Fabrication of Polymers: Thermoforming, Extrusion, Blow, Compression, Injection, Reaction Injection, Transfer, Cold, Rotational, & Foam Molding, Calendering, Spinning, Dipping, etc. For Fabrication of Ceramics: Blow Molding, Dry Pressing, Isostatic Pressing, Slip Casting, Plastic Forming Techniques For Fabrication of Fiber Reinforced Composites: Pultrusion, Filament Winding, Vacuum-bag and Pressure-bag Molding, Resin- transfer Molding, Spray Molding, Sheet Stamping, Braiding, 3D- Knitting & Weaving, Powder Metallurgy Processes [Late Nineteenth Century]
[1] CLASSIFICATION OF VARIOUS MANUFACTURING PROCESSES (Cont…) Basic Nature Traditional or Conventional Processes Advanced or Unconventional Processes Deforming Processes [Formative: ShapesThe Material In Solid State Using Property Of Plasticity.] Metal Forming Processes Advanced Metal Forming Processes Hot- working Cold-working Processes High Energy Rate Forming (HERF) Processes: Electromagnetic Forming, Explosive Forming, and Electro-hydraulic Forming. Laser Bending, 3d-laser Forming, Hot Isostatic Pressing (HIP) For Sheet Metal Components: Electroforming, Plasma Spray Forming Rolling, Forging, Extrusion, Hot- drawing, Piercing Squeezing: Cold Rolling, Cold Forging , Cold Extrusion, Swaging, Sizing, Riveting, Staking, Coining, Peening, Burnishing, Hubbing, and Thread Rolling. Bending: Angle Bending, Roll Bending, Draw and Compression Bending, Roll- forming, Seaming, Flanging, and Straightening. Shearing: Slitting, Blanking, Piercing, Lancing, Perforating, Notching, Nibbling, Shaving, Trimming, Cutoff, and Dinking. Drawing: Spinning, Embossing, Stretch Forming, and Ironing Sheet-metal Forming Operations
[1] CLASSIFICATION OF VARIOUS MANUFACTURING (Continued) Basic Nature Traditional or Conventional Processes Advanced/Unconventional Processes Material Removal Processes Subtractive : Shape the Product by Removing the Excess Material] Conventional Machining Processes [19th Century Onwards] AMPs [After 1945] Axi-symmetric Parts Prismatic Parts General Mechanical Chemical Electro- chemical Thermal Turning, Facing, Taper Turning, Threading, Drilling, Boring, Reaming, etc. Milling, Shaping, Planning, etc. Sawing, Broaching, Hobbing, Grinding, Honing, Lapping, etc. USM, AJM, WJM, AWJM, IJM, AFM, MAF, MRF CHM, PCM, TCM ECM EDM EBM LBM IBM PAM
[1] CLASSIFICATION OF VARIOUS MANUFACTURING (Continued) Joining Or Consolidation Or Fabrication Processes [For assembling the various component s of a product] Joining Processes Advanced Welding Techniques: EBW, LBW, USW Welding of Plastics (only for Thermoplastics) : USW, LBW, Friction/spin Welding Vibration Welding Friction stir welding Hot-plate welding Hot-gas welding Implant welding Infrared welding Micro-wave welding Mechanical Bonding Atomic Bonding Tempor - ary Permanent or semi- permanent Solid state welding Liquid state or Fusion Welding Solid/ Liquid state Electrical Chemical Thread joints Rivets, Stitches, Staples, Shrink-fits, Friction, Forge, Diffusion welding, Cold Welding: Pressure, Explosive, Ultrasonic Welding Arc welding: Using Consumable Electrode SMAW , GMAW , FCAW, SAW; Those using Non- consumable Electrode: GTAW, PAW, SW . Resistance welding: RSW, RSEW, RPW. Induction welding Gas welding: OAW , and PGW, Thermit welding Brazing, Soldering, and Adhesive bonding
[1] CLASSIFICATION OF VARIOUS MANUFACTURING (Continued) Basic Nature Traditional or Conventional Processes Advanced or Unconventional Processes Heat Treatment or Bulk Property Enhancing Processes [To modify the bulk properties.] HARDENING TECHNIQUES SURFACE HARDENING (ie Selective Heating) Processes: Flame Hardening, and Induction Hardening Laser Beam Hardening and Electron Beam Hardening CASE HARDENING (ie Surface Chemistry Altering) Processes: Carburizing (pack, gas, and liquid type), Nitriding, Cyaniding or Carbonitriding. Additional Layer Depositing: Ionitriding, Ion Carburizing, Ion Plating, and Ion Implantation CRACK REDUCTION TECHNIQUES: Austempering, Martempering / Marquenching DUCTILITY, TOUGHNESS, and MACHINABILITY changing processes: Annealing (Full and Process type), Normalizing, Tempering, Spheroidizing. STRENGTHENING processes: Solid Solution Strengthening, Grain Size Refinement, Strain Hardening, Precipitation or Age Hardening, Dispersion Hardening, and Phase Transformation Hardening
Basic Nature Traditional or Conventional Processes Advanced or Unconven tional Processes Finishing And Surface Treatment Processes [To modify the surface properties.] BURR REOMVAL: Grinding, Chamfering, Filing, Centrifugal and Spindle Finishing, Thermal- energy Deburring, Power Sanding, Power Brushing, and Mechanical Cleaning Processes as described below. For burr Removal: USM, AJM, WJM, AWJM, AFM, CHM, ECDE MECHANICAL CLEANING and FINISHING: Abrasive Cleaning, Barrel Finishing OrTumbling,Vibratory Finishing, Belt Sanding,Wire Brushing, Buffing, Electro-polishing. CHEMICAL CLEANING: Vapor Degreasing, Acid Pickling, Alkaline, Solvent,And Ultrasonic Cleaning. COATING TECHNIQUES COATING (Liquid/Gas Deposition): Painting, Chemical Conversion Coating, Hot Dip Coating, Electro-plating, Anodizing, Electroless or Autocatalytic Plating, Mechanical Plating, Porcelain Enameling. CLADDING (Solid deposition) VAPORIZED METAL COATING Physical Vapor Deposition (PVD): Vacuum Metallizing, Sputtering, Ion Plating Chemical Vapor Deposition (CVD) [1] CLASSIFICATION OF VARIOUS MANUFACTURING (Continued)
Types of AMPs  Basic AMPs: 15 (8 Mechanical + 1 Electrochemical + 1 Chemical + 5 Thermal)  Derived AMP: Modification of Basic AMP to Meet Specific Objectives Derived AMPs from ECM Electro Stream Drilling (ESD) Shaped Tube Electro Machining (STEM) Electrolytic Jet Drilling (EJD) Derived AMP from CHM Photo Chemical Machining (PCM) Derived AMP from EDM Wire Electro Discharge Machining (WEDM) Derived AMP from AFM Centrifugal Force Assisted Abrasive Flow Machining (CFA-AFM)  Hybrid Machining Processes (HMPs)
[1] Concept of HMP Combining Either Two or More than Two AMPs or AMP + Conventional Machining Process [2] When to Conceptualize and Develop an HMP ?  To Simultaneously Exploit the Potentials and Capabilities of the Constituent Processes; and / or  To Minimize the Adverse Effects Induced When a Constituent Process is Used Independently  Generally, Development of an HMP is either Material or Shape Application Specific Hybrid Machining Processes (HMPs)
HMPs are Gaining Considerable Attraction  Meet Some of the Ultraprecision Machining Requirements  Meet High Productivity Requirements for the Components Made of Advanced DTM Materials  Meet the Challenging Stringent Design Requirements  Meet Extreme Surface Quality andTolerance Requirement Types of HMPs [Can be Classified Into Two Major Categories (Kozak & Rajurkar, 2001)]  Processes in which Constituent Processes are Directly Involved in Material Removal;  Processes in which only ONE of the Participating Processes Directly Removes the Material while others Only ASSIST in Removal By Changing the Conditions of Machining in a Positive Manner  Most of the HMPs are in their Inception and Development Phase  Sustained Research is Required to Transform HMPs into a Matured Manufacturing Technology and forTheir Successful Commercialization and Industrial Applications
Process Combining Energy Sources Mechanism of Material Removal Tool Transfer Media Conventional Machining + Electrochemical AMP ECH Electrochemical + Mechanical Electrochemical Dissolution and Abrasion Abrasive Sticks Electrolyte ECG Electrochemical + Mechanical Electrochemical Dissolution and Abrasion Abrasive Wheel Electrolyte ECAG Electrochemical + Mechanical Electrochemical Dissolution and Abrasion Metal Bonded Abrasive Wheel Electrolyte Conventional Machining + Thermal AMP AEDM Mechanical + Thermal Melting, Evaporation and Abrasion Loose Abrasive Particles Dielectric EDAG Mechanical + Thermal Melting, Evaporation and Abrasion Metal Bonded Abrasive Wheel Dielectric EDDG Mechanical + Thermal Melting, Evaporation and Abrasion Diamond wheel Dielectric LAT Mechanical + Thermal Shearing and Heating Turning Tool Air PAT Mechanical + Thermal Shearing and Heating Turning Tool Air LAE Chemical + Thermal Chemical Dissolution and Heating Mask Etchant Conventional Machining + Mechanical AMP RUM Mechanical + Ultrasonic Vibration Abrasion Sonotrode having Diamond Abrasives Coolant UAT Mechanical + Ultrasonic Vibration Shearing Turning Tool Air Examples of HMPs [Conventional Machining + AMP]
Process Combining Energy Sources Mechanism of Material Removal Tool Transfer Media Electrochemical + Thermal ECSM or ECAM Electrochemical + Thermal Melting and/Or Evaporation Electrode Electrolyte LAECM Electrochemical + Thermal Electrochemical Dissolution and Heating Electrode Electrolyte Electrochemical + Mechanical USECM Electrochemical + Ultrasonic Vibration Electrochemical Dissolution Sonotrode Electrolyte ECMAF Electrochemical + Mechanical Electrochemical Dissolution + Abrasion Abrasives Electrolyte Mechanical + Thermal USEDM Thermal + Ultrasonic Vibration Melting and Evaporation Sonotrode Dielectric USLBM Thermal + Ultrasonic Vibration Melting and Evaporation Laser Beam Air Two Mechanical AMPs MRAFF Two Mechanical AMPs Shearing Abrasives MR Fluid More than Two AMPs BEDMM Electrochemical + Mechanical + Thermal Electrochemical, Melting and Mechanical Rupture Rotating Metal Brush Water Glass Solution In Water Examples of HMPs [Two or More AMPs]
Typical Examples of Parts Developed by AMPs Figure:1Typical parts made by electrochemical machining. (a) Turbine blade made of nickel alloy of 360 HB. Note the shape of the electrode on the right. (b) Thin slots on a 4340-steel roller-bearing cage. (c) Integral airfoils on a compressor disk. MALE FEMALE PRECISION WIRE EDM Design Made using 3D Printing
Important Characteristics of AMPs Process performance is independent of Workpiece Material properties such as hardness.Toughness, ductility, brittleness etc. Process Performance highly depends upon the thermal, electrical, magnetic and chemical properties of the workpiece material Process utilizes different types of source energy i.e. Mechanical, Thermal, Electrical and Chemical in its direct form Usually AMPs Possesses lower material removal rate as compared to conventional processes but in turns AMPs provide high quality parts Initial investment cost of setting an AMP is high due to costly machine tools and high operating costs
Classification of UNconventional machining Processes • Mechanical mechanical erosion of work material by a high velocity ‑ stream of abrasives or fluid (or both) • Electrical electrochemical energy to remove material (reverse of ‑ electroplating) • Thermal – thermal energy applied to small portion of work surface, causing that portion to be fused and/or vaporized • Chemical – chemical etchants selectively remove material from portions of workpart, while other portions are protected by a mask
Mechanical Energy Processes • Ultrasonic machining • Water jet cutting • Abrasive water jet cutting • Abrasive jet machining • Abrasive flow machining
Ultrasonic Machining • Ultrasonic vibration (20,000 Hz) of very small amplitudes (0.04-0.08 mm) drive the form tool (sonotrode) of ductile material (usually soft steel) • An abrasive slurry is flowed through the work area • The workpiece is brittle in nature (i.e. glass) • The workpiece is gradually eroded away.
Ultrasonic Machining (USM) • Abrasives contained in a slurry are driven at high velocity against work by a tool vibrating at low amplitude and high frequency • Tool oscillation is perpendicular to work surface • Abrasives accomplish material removal • Tool is fed slowly into work • Shape of tool is formed into part
USM Applications • Hard, brittle work materials such as ceramics, glass, and carbides • Also successful on certain metals, such as stainless steel and titanium • Shapes include non-round holes, holes along a curved axis • “Coining operations” - pattern on tool is imparted to a flat work surface
• Uses high pressure, high velocity stream of water directed at work surface for cutting Water Jet Cutting (WJC)
WJC Applications • Usually automated by CNC or industrial robots to manipulate nozzle along desired trajectory • Used to cut narrow slits in flat stock such as plastic, textiles, composites, floor tile, carpet, leather, and cardboard • Not suitable for brittle materials (e.g., glass)
WJC Advantages • No crushing or burning of work surface • Minimum material loss • No environmental pollution • Ease of automation
Abrasive Water Jet • High pressure water (20,000-60,000 psi) • Educt abrasive into stream • Can cut extremely thick parts (5-10 inches possible) • Thickness achievable is a function of speed • Twice as thick will take more than twice as long • Tight tolerances achievable • Current machines 0.002” (older machines much less capable ~ 0.010” • Jet will lag machine position, so controls must plan for it
• High velocity stream of gas containing small abrasive particles Abrasive Jet Machining (AJM)
AJM Application Notes • Usually performed manually by operator who aims nozzle • Normally used as a finishing process rather than cutting process • Applications: deburring, trimming and deflashing, cleaning, and polishing • Work materials: thin flat stock of hard, brittle materials (e.g., glass, silicon, mica, ceramics)
Electrochemical Machining Processes • A group of processes in which electrical energy is used in combination with chemical reactions to remove material • Reverse of electroplating • Work material must be a conductor • Processes: • Electrochemical machining (ECM) • Electrochemical deburring (ECD) • Electrochemical grinding (ECG)
• Material removal by anodic dissolution, using electrode (the tool) in close proximity to work but separated by a rapidly flowing electrolyte Electrochemical Machining (ECM)
ECM Applications • Die sinking - irregular shapes and contours for forging dies, plastic molds, and other tools • Multiple hole drilling - many holes can be drilled simultaneously with ECM • Holes that are not round • Rotating drill is not used in ECM • Deburring
• Adaptation of ECM to remove burrs or sharp corners on holes in metal parts produced by conventional through hole drilling ‑ Electrochemical Deburring (ECD)
• Special form of ECM in which grinding wheel with conductive bond material augments anodic dissolution of metal part surface Electrochemical Grinding (ECG)
Applications and Advantages of ECG • Applications: • Sharpening of cemented carbide tools • Grinding of surgical needles and other thin-wall tubes, and fragile parts • Advantages: • Deplating responsible for 95% of metal removal • Because machining is mostly by electrochemical action, grinding wheel lasts much longer
Thermal Energy Processes- Overview • Very high local temperatures • Material is removed by fusion or vaporization • Physical and metallurgical damage to the new work surface • In some cases, resulting finish is so poor that subsequent processing is required ©2013 John Wiley & Sons, Inc. M P Groover, Principles of Modern Manufacturing 5/e
Thermal Energy Processes • Electric discharge machining • Electric discharge wire cutting • Electron beam machining • Laser beam machining • Plasma arc machining
Electric Discharge Processes • Metal removal by a series of discrete electrical discharges (sparks) causing localized temperatures high enough to melt or vaporize the metal • Can be used only on electrically conducting work materials • Two main processes: • Electric discharge machining • Wire electric discharge machining
• (a) Setup of process and (b) close up view of gap, showing discharge and metal ‑ removal Electric Discharge Machining (EDM)
Work Materials in EDM • Work materials must be electrically conducting • Hardness and strength of work material are not factors in EDM • Material removal rate depends on melting point of work material
EDM Applications • Tooling for many mechanical processes: molds for plastic injection molding, extrusion dies, wire drawing dies, forging and heading dies, and sheetmetal stamping dies • Production parts: delicate parts not rigid enough to withstand conventional cutting forces, hole drilling where hole axis is at an acute angle to surface, and machining of hard and exotic metals
• Special form of EDM that uses a small diameter wire as electrode to cut a narrow kerf in work Wire EDM
Operation of Wire EDM • Work is fed slowly past wire along desired path • Similar to a bandsaw operation • CNC used for motion control • While cutting, wire is continuously advanced between supply spool and take up spool to maintain a constant diameter ‑ • Dielectric required, using nozzles directed at tool work interface or ‑ submerging workpart
• Definition of kerf and overcut in electric discharge wire cutting Wire EDM
Wire EDM Applications • Ideal for stamping die components • Since kerf is so narrow, it is often possible to fabricate punch and die in a single cut • Other tools and parts with intricate outline shapes, such as lathe form tools, extrusion dies, and flat templates
Wire EDM Application • Irregular outline cut from a solid slab by wire EDM (photo courtesy of Makino).
Laser Beam Machining • Lasers are high intensity focused light sources • CO2 • Most widely used • Generally more powerful that YAG lasers • Cutting operations commonly • Nd:YAG (Neodymium ions in an Yttrium Aluminum Garnet) • Less powerful • Etching/marking type operations more commonly • Limited in depth of cut (focus of light) • Would limit workpiece to less than 1 inch (< ½” typically)
WORKING OF IBM Process: • An ion source generates ions, usually argon or other inert gases, and accelerates them to high velocities. • The ion beam is directed toward the workpiece, where ions collide with the material and cause atoms to dislodge, effectively "sputtering" the material away. • IBM is a non-contact process, so there is minimal thermal impact on the material. Materials Machined: •Ideal for hard materials like ceramics, metals, semiconductors, and optical glass. •Used in applications where chemical reactions might alter the material’s properties.
Mechanism of Material Removal In Ion Beam Machining  Particle beam consisting of ionized atoms i.e. ions .  A stream of ions of an inert gas, such as argon or metal such as gallium is accelerated in a vacuum by high energies and directed toward a solid work-piece.  Ion beam knocks off atoms from workpiece by transferring kinetic energy and momentum to atoms on the surface of the object,  Sputtering off: knocking out atoms from the work-piece surface through the transfer of kinetic energy from the incident ion to the target atoms  Removal of atoms occurs when the energy transferred exceeds the binding energy
It is a process that uses a high-velocity jet of ionized gas to cut and remove material from a workpiece: •How it works A plasma torch generates a high-temperature plasma jet by passing gas through an electric arc between a cathode and anode. The plasma jet melts and displaces the material from the workpiece. •Temperature The plasma jet can reach temperatures of 11,000– 30,000°C. Plasma arc machining (PAM)
•Materials PAM is often used to cut electrically conductive materials like steel, aluminum, brass, and copper. •Applications PAM is used in fabrication and welding shops, automotive repair, industrial construction, and salvage operations. •Gases The gas used depends on the material being cut. For example, a mixture of argon and hydrogen can be used for thicker stainless steel or aluminum, while a mixture of hydrogen and nitrogen or methane and nitrogen can be used for thinner stainless steel. •Advantages PAM is known for its high speed, precision cuts, and low cost of operation. Plasma is a superheated, electrically ionized gas that is the fourth state of matter, along with solid, liquid, and gas. It is highly conductive and very bright.
Hybrid Machining Processes • Hybrid production/manufacturing means the combination of processes/machines in order to produce parts in a more efficient and productive way. • A general objective of hybrid manufacturing is the ‘‘1 + 1 = 3’’effect, meaning that the positive effect of the hybrid process is more than the double of the advantages of the single processes. • Hybrid can have several meanings: combination of different active energy sources which act at the same time in the processing zone (e.g. laser assisted turning); processes which combine process steps that are usually performed in two or more process steps
Classification of hybrid machining processes • Combined or mixed-type processes in which all constituent processes are directly involved in the material removal. • Assisted-type processes in which only one of the participating processes directly remove material, while the other only assists in removal by having a positive effect on the conditions of machining
Assisted hybrid processes 1. Vibration assisted hybrid machining processes: • Vibration assisted grinding is a rather new technology where a superposition of conventional grinding and a vibration (most often in the ultrasonic range) is established.
Vibration assisted EDM • In micro-EDM process flushing conditions and discharge gap state have been identified as main influences. Improved flushing strategies and optimized discharge gap control circuits have led to great improvements. • The periodic relative movement between tool and workpiece causes a flow of the dielectric and an agitation of the debris particles in the dielectric medium. Due to this phenomenon, a settlement of debris on the bore ground and the agglomeration of particles are reduced and the state of the gap is equalized.
Vibration assisted EDM In vibration assisted EDM, an additional relative movement is applied in the system tool electrode, work piece and dielectric fluid in order to increase the flushing efficiency, resulting in a higher material removal rate and better process stability.
Ultrasonic-Assisted ECM (USECM) • Electrochemical dissolution and the formation of a passivating oxidelayer occur on the work piece surface by ion formation and movement within the electrolyte producing a high intensity current flow. • The passivating layer is then removed by these ultrasonically accelerated abrasives that impact the work piece surface. This process also helps to maintain a constant inter-electrode gap.
2. Heat-Assisted HMPs • The use of an external heat source improves the machinability by minimizing the machining forces, improving the work surface, integrity and enhancing the tool life. This heat source may be in the form of a laser beam, electron beam, plasma beam, high-frequency induction or electric current etc. • Laser-assisted machining is one of the important and most widely used category of the heat- assisted HMPs. • Laser-assisted HMPs are of two types: • Laser-assisted mechanical machining: in which, a laser is used to heat the work piece ahead of the cutting tool during conventional machining processes such as turning, milling and grinding. • Laser-assisted advanced machining: where laser assistance enhances the material removal in electrolytic dissolution and electro discharge-based AMPs.
I-Laser assisted turning • In this process, the main material removal mechanism is still the one occurring in conventional cutting, but the laser action softens the work piece material, so machining of high alloyed steels or some ceramics becomes easier. • The laser beam is directly focused in front of the cutting tool, resulting in easier machining and higher process performance.
II-Laser assisted ECM (LAECM) The primary role of a laser in ECM is to improve the localization of the dissolution process. The main mechanism of material removal in laser-assisted ECM (LAECM) is enhanced by electrolytic dissolution because of an improved thermal activation brought upon by a focused laser beam. Additionally, it also helps in removing the passivating metallic oxide layers formed on the workpiece due to the evolution of oxygen at the anode during the electrolysis process.
III-Laser-Assisted EDM (LAEDM) • EDM drawbacks: Lengthy machining times and high tool wear • Laser drawbacks: Formation of a recast layer and heat-affected zones (HAZ) and low surface quality of the work piece. • Solution: • Hybridization of LBM and EDM as LAEDM addresses their respective disadvantages. LAEDM is generally used in micro-machining applications for reducing production time and eliminating the recast layer and HAZ caused by laser ablation
Laser-Assisted EDM (LAEDM) • A short-pulsed laser beam capable of producing high ablation rates is used to roughly pre- machine the basic part features (i.e. groove, hole, cavity). This is subsequently followed by micro- EDM within a suitable dielectric to remove the surface defects caused by the thermal effects of laser ablation and to finish the feature
3. Magnetic field assisted machining processes • Magnetic field-assisted HMPs rely on the enhancement of the primary machining/finishing process by the addition (assistance) of magnetic field with the aim to improve work piece surface quality and material removal rate. • Magnetic field-assisted EDM (MAEDM) • Magnetic field-assisted abrasive flow machining (MAAFM) • I. Magnetic Field-Assisted EDM (MAEDM) • Debris accumulation in the machining zone that adversely affects performance and efficiency has always been a perennial problem in EDM. • Adding magnetic field enhances the process stability and increases the efficiency of the EDM component by effective removal of machining debris from the machining zone.
1.Magnetic Field-Assisted EDM (MAEDM) The introduction of the magnetic field exerts a magnetic force perpendicular to the electrode’s motion. As a result, debris particle in the machining zone is subjected both to a magnetic force and to a centrifugal force. The resultant force which is the vector summation of the magnetic and centrifugal forces ensures effective and rapid flushing of debris particles.
2.Magnetic field-assisted abrasive flow machining Magnetic field-assisted abrasive flow machining (MAAFM) is an important hybrid AFM process where the assistance of a magnetic field provides the means of controlling the cutting forces and consequently the outcome of the process includes higher surface finish and finishing rate. This process is capable of producing a surface roughness as small as 8-10 nm.
4.External Electric Field-Assisted machining • Laser Percussion Drilling for Highly Reflective Metals • Laser percussion drilling has gained great attention in the industry due to its wide industrial applicability and usage in processing of various materials, such as metals, glass, and ceramics. • Laser percussion drilling is also characterized by a noncontact machining process, smaller beam spot size, high operating speeds, great flexibility, and accuracy. However, it is difficult to apply laser percussion drilling to highly reflective target surfaces, such as aluminium, which reflect the optical energy and dramatically reduce the processing efficiency • This drawback lengthens the drilling time, increasing the cost of the process and decreasing the yield. • Using the electric field influences the behaviour of the plasma plume during laser percussion drilling. The depths of the drilled holes, obtained in the presence of applied electric field, are deeper than those obtained in the normal case. These results are due to the effect of the electric force by which the plume particle could be accelerated in the electric field
Femto second laser micromachining of silicon with an external electric field • Machining of silicon wafers with fs lasers the debris was formed as a result of aggregation of small particles such as atoms or atomic clusters on the substrate surface instead of large-scale droplets or fragments, which are commonly observed with nanosecond lasers. • In order to prevent particles from redepositing onto the Si surface an electric field during the fs laser machining is applied. It is assumed that the charged ions in the plasma cloud would be attracted to the electrodes fs laser micromachining of Si without the external
Combined hybrid machining • Combined or mixed HMPs are those processes in which two or more energy sources/tools/mechanisms are combined and have a synergetic effect on the material removal process. They can further be categorized as electrochemical HMPs and thermal HMPs. • Electrochemical Hybrid Machining Processes (ECHMP) • ECM offers many advantages, namely process performance being independent of mechanical properties of the workpiece material production of largely stress-free surface good surface finish and integrity higher productivity due to higher MRRs
Electrochemical Hybrid Machining Processes (ECHMP) • Limitations: Passivation of work piece surface by non-conducting metal oxide layer formation due to the evolution of oxygen gas at the anode applicability to only electrically conducting materials corrosion of machining elements and surroundings due to the use of an electrolyte chemical damage caused to work piece surface the dependence of accuracy on the inter-electrode gap which requires efficient flushing
Need of ECHMP • Conventional finishing processes such as grinding, mechanical honing, buffing and superfinishing are inexpensive and give good surface quality, but the use of abrasives imparts some inherent limitations such as high tool wear; low productivity and mechanical damage to the finished surface. • Solution: • Combine ECM with some conventional machining/finishing or AMP to develop and electrochemical HMP (ECHMP)
Electrochemical Grinding (ECG) • ECG is the result of hybridizing ECM with the abrasive action of conventional grinding to machine hard and fragile electrically conducting materials efficiently, economically and productively without affecting the useful properties of these materials. • ECG offers accurate and largely surface residual stress-free machining with no burrs and heat affected zone (HAZ) and, therefore, little distortion
Equipment and Working Principle The non-conducting abrasive particles protrude just beyond the surface of the bonding material of the wheel helping to maintain a constant inter-electrode gap and act as spacers. Bonding materials such as copper, brass, nickel or copper impregnated resin are commonly used for the manufacture of metal-bonded grinding wheels. Functions of abrasive particles: to maintain the electrical insulation between anode workpiece and cathode. continuously remove any passive layer that may be formed on the workpiece surface by chemical reaction To determine workpiece shape and size
Three distinct zones in ECG process Zone I, the material removal is purely due to electrochemical dissolution In Zone II, the gas bubbles in the gap yield higher MRRs. Chemical or electrochemical reaction may result in the formation of a passive layer on the workpiece surface. The abrasive particles not only remove material from the work surface in the form of chips but also remove the non-reactive oxide layer. Zone III, the material removal is done completely by electrochemical dissolution. This zone starts at the point where the wheel lifts just beyond the work surface. This zone contributes by removal of burrs that formed on the workpiece in zone II
EDM Combined with Conventional Machining • Electric Discharge Grinding (EDG): EDG is a thermal HMP An electrically conductive grinding wheel is used as a tool electrode. Material removal occurs due to the electro discharge action. Abrasive component of the process ensures effective flushing which results in improved material removal rate and enhanced surface finish as compared to the conventional EDM process
Electric Discharge Diamond Grinding (EDDG) ) mechanism of material removal in EDAG A metal-bonded grinding wheel with embedded abrasive particles is used to enhance the machining productivity and surface finish. Al2O3, SiC and CBN are commonly used abrasive in this process. When diamond is used as abrasive, this process is known as electric discharge diamond grinding (EDDG).
Electrochemical Discharge Machining (ECDM) • ECDM is a combination of electric discharge machining (EDM) and electrochemical machining (ECM). Used for the machining of electrically non-conducting materials such as insulating ceramics, glass, polymers etc. • A complex combination of electrolytic dissolution and spark erosion. Schematic of ECDM process Process mechanism of ECDM
Electrochemical Discharge Grinding (ECDG) Electrochemical discharge grinding (ECDG) hybridizes spark erosion, electrolytic dissolution and mechanical abrasion to machine electrically conductive workpieces Dissolution occurs at the workpiece (anode) due to the electrochemical reaction A passivating oxide layer is also formed on the work surface during the electrochemical reaction. Subsequent electro-erosion phase, the spark discharges de- passivate the oxide layer Enhances the effectiveness of the electrochemical dissolution and thereby improves the workpiece material removal rate.
Additive Manufacturing Additive Manufacturing (AM) refers to a process by which digital 3D design data is used to build up a component in layers by depositing material. (from the International Committee F42 for Additive Manufacturing Technologies, ASTM)..
Subtractive vs Additive
Generic AM Process
Medical Applications Hip socket, Ala Ortho, Italy, made on Arcam machine Laser Sintered Hearing Aids, EOS/Materialise
Beauty and the beak
Food Printers MIT Media Lab FabCafe in the Shibuya, Tokyo offers custom-printed chocolate, that resemble a customer’s face. It’s done with 3D printing technology “Eat Your Face Machine” (EYFM) is a 3D printer developed by David Carr and the MIT Media Lab
AM : For household Products
3d Printed House
AM Benefits : Weight Reduction
AM Benefits : Complexity for free
AM : Customized Medical Equipments
Evolution
Pros and Cons
AM processes are classified into seven categories 1) Vat Photopolymerisation/Steriolithography 2) Material Jetting 3) Binder jetting 4) Material extrusion 5) Powder bed fusion 6) Sheet lamination 7) Directed energy deposition
Vat photopolymerization/Steriolithography • Laser beam traces a cross-section of the part pattern on the surface of the liquid resin • SLA's elevator platform descends • A resin-filled blade sweeps across the cross section of the part, re-coating it with fresh material • Immersed in a chemical bath Stereolithography requires the use of supporting structures
Material Jetting • Drop on demand method • The print head is positioned above build platform • Material is deposited from a nozzle which moves horizontally across the build platform • Material layers are then cured or hardened using ultraviolet (UV) light • Droplets of material solidify and make up the first layer. • Platform descends • Good accuracy and surface finishes
Binder Jetting • A glue or binder is jetted from an inkjet style print head • Roller spreads a new layer of powder on top of the previous layer • The subsequent layer is then printed and is stitched to the previous layer by the jetted binder • The remaining loose powder in the bed supports overhanging structures
Material Extrusion/FDM • Fuse deposition modelling (FDM) • Material is drawn through a nozzle, where it is heated and is then deposited layer by layer • First layer is built as nozzle deposits material where required onto the cross sectional area. • The following layers are added on top of previous layers. • Layers are fused together upon deposition as the material is in a melted state.
Powder Bed Fusion • Selective laser sintering (SLS) • Selective laser melting (SLM) • Electron beam melting (EBM) No support structures required PROCESS • A layer, typically 0.1mm thick of material is spread over the build platform. • The SLS machine preheats the bulk powder material in the powder bed • A laser fuses the first layer • A new layer of powder is spread. • Further layers or cross sections are fused and added. • The process repeats until the entire model is created.
Sheet Lamination • Metal sheets are used • Laser beam cuts the contour of each layer • Glue activated by hot rollers PROCESS 1. The material is positioned in place on the cutting bed. 2. The material is bonded in place, over the previous layer, using the adhesive. 3. The required shape is then cut from the layer, by laser or knife. 4. The next layer is added.
Directed Energy Deposition • Consists of a nozzle mounted on a multi axis arm • Nozzle can move in multiple directions • Material is melted upon deposition with a laser or electron beam PROCESS 1. A4 or 5 axis arm with nozzle moves around a fixed object. 2. Material is deposited from the nozzle onto existing surfaces of the object. 3. Material is either provided in wire or powder form. 4. Material is melted using a laser, electron beam or plasma arc upon deposition. 5. Further material is added layer by layer and solidifies, creating or repairing new material features on the existing object.
Challenges
THANK YOU

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Advance manufacturing practices mechanical engineering

  • 1. Advanced Manufacturing Processes (AMPs) Short-term Course on Manufacturing 4.0 By Dr. Pankaj Chhabra Director Edu-Crafter Academy
  • 2. • Aims • To provide and insight on advanced manufacturing processes • To provide details on why we need AMP and its characteristics • Topics Covered • Introduction and requirement of AMPs • Classification of AMPs • HMPs • Classification of HMPs • Various important types of AMPs
  • 3. Materials Used In Engineering Applications Plastics and Composites Ceramics HOW TO MACHINE THEM ? SOLUTION • Getting More Popularity • Definite Advantages Over Others Engineering Materials Having Much Superior Properties • Ultra High Strength, Hardness Very High Temperature Resistance • Difficult To Machine By Conventional Machining Methods Metal and its Alloys Advanced Manufacturing/Machining Processes
  • 4. Need of Advanced Manufacturing/Machining Processes • Limitations of conventional machining methods (workpiece hardness, surface roughness, 3-d parts and complex geometries) Increased Workpiece Hardness Decreased Economic Cutting Speed Lower Productivity • Rapid Improvements In The Properties Of Materials (Workpiece Hardness, Strength, Etc.) • Metals & Non – Metals : Stainless Steel , High Strength Temperature Resistant(hsrt) Super Alloys: Stellite, Incoloys Etc. • Tool Material Hardness >> Workpiece Hardness  Requires Much Superior Quality Of Tool Materials
  • 5. Product Requirements  Complex Shapes  Machining In Inaccessible Areas  Low Tolerances (Say,10 µm)  Better Surface Integrity (No Surface Defects, Etc.)  High Surface Finish (Nano Level Ra Value =>Nm)  Miniaturization Of Products (Examples: Landline Phone & Mobile, Old Computers & Lap Top, Etc.)  High Mrr Need Of Advanced Manufacturing/ Machining Processes ?? High Production Rate While Processing Difficult –To- Machine Materials Low Cost Of Production Precision And Ultra precision Machining (Nano-meter Machining) Requires Material Removal In The Form Of Atoms And / Or Molecules ADVANCED MACHINING PROCESSES (Amps)
  • 6. Behaviour and Manufacturing Properties of Engineering Materials Structure of Material Physical and Chemical Properties Mechanical Properties Property Modification  Atomic Bond: Metallic, Ionic, Covalent  Crystalline  Amorphous or Non-Crystalline  Partly Crystalline  Polymer Chains  Melting Point  Density  Specific Heat  Thermal Conductivity  Thermal Expansion  Electrical Conductivity  Magnetic Properties  Oxidation  Corrosion Strength  Ductility  Elasticity  Stiffness  Hardness  Toughness  Fatigue  Creep Resistance to Wear, Corrosion, Oxidation  Hot Hardness and Strength  Heat Treatment  Annealing  Tempering  Normalizing  Hardening  Alloying  Reinforcement s  Composites  Laminations  Fillers  Surface Treatment
  • 7. [1] CLASSIFICATION OF VARIOUS MANUFACTURING PROCESSES Basic Nature Traditional or Conventional Processes Advanced or Unconventional Processes Primary Forming Processes [Additive Or Accretion: Create Shape From Molten, Gaseous, or Solid Particles] Casting and Molding Processes Rapid Prototyping Processes [After 1990] Single-Use or Expendable Mold Casting Multiple-Use Mold Casting Liquid Based Solid Based Powder Based Multiple-use Pattern Single-use Pattern Permanent Mold Casting: Slush casting, Corthias Casting Low- pressure Vacuum Casting Die Casting, Squeeze Casting, Centrifugal Casting, Semicentrifugal Casting Centrifuging Casting, Continuous Casting, Electromagnetic Or Levitation Casting SLA, SLT, SGC, SOUP, SCS, etc. FDM, LOM, MJM, SAHP, etc. SLS, BPM, TDP , MJS, DSPC, etc. Sand Casting, Plaster Mold Casting, Ceramic Mold Casting, Rubber Mold Casting, Graphite Mold Casting, Shell Molding, Investment Casting, Full-mold and Lost- Foam Casting For Fabrication of Polymers: Thermoforming, Extrusion, Blow, Compression, Injection, Reaction Injection, Transfer, Cold, Rotational, & Foam Molding, Calendering, Spinning, Dipping, etc. For Fabrication of Ceramics: Blow Molding, Dry Pressing, Isostatic Pressing, Slip Casting, Plastic Forming Techniques For Fabrication of Fiber Reinforced Composites: Pultrusion, Filament Winding, Vacuum-bag and Pressure-bag Molding, Resin- transfer Molding, Spray Molding, Sheet Stamping, Braiding, 3D- Knitting & Weaving, Powder Metallurgy Processes [Late Nineteenth Century]
  • 8. [1] CLASSIFICATION OF VARIOUS MANUFACTURING PROCESSES (Cont…) Basic Nature Traditional or Conventional Processes Advanced or Unconventional Processes Deforming Processes [Formative: ShapesThe Material In Solid State Using Property Of Plasticity.] Metal Forming Processes Advanced Metal Forming Processes Hot- working Cold-working Processes High Energy Rate Forming (HERF) Processes: Electromagnetic Forming, Explosive Forming, and Electro-hydraulic Forming. Laser Bending, 3d-laser Forming, Hot Isostatic Pressing (HIP) For Sheet Metal Components: Electroforming, Plasma Spray Forming Rolling, Forging, Extrusion, Hot- drawing, Piercing Squeezing: Cold Rolling, Cold Forging , Cold Extrusion, Swaging, Sizing, Riveting, Staking, Coining, Peening, Burnishing, Hubbing, and Thread Rolling. Bending: Angle Bending, Roll Bending, Draw and Compression Bending, Roll- forming, Seaming, Flanging, and Straightening. Shearing: Slitting, Blanking, Piercing, Lancing, Perforating, Notching, Nibbling, Shaving, Trimming, Cutoff, and Dinking. Drawing: Spinning, Embossing, Stretch Forming, and Ironing Sheet-metal Forming Operations
  • 9. [1] CLASSIFICATION OF VARIOUS MANUFACTURING (Continued) Basic Nature Traditional or Conventional Processes Advanced/Unconventional Processes Material Removal Processes Subtractive : Shape the Product by Removing the Excess Material] Conventional Machining Processes [19th Century Onwards] AMPs [After 1945] Axi-symmetric Parts Prismatic Parts General Mechanical Chemical Electro- chemical Thermal Turning, Facing, Taper Turning, Threading, Drilling, Boring, Reaming, etc. Milling, Shaping, Planning, etc. Sawing, Broaching, Hobbing, Grinding, Honing, Lapping, etc. USM, AJM, WJM, AWJM, IJM, AFM, MAF, MRF CHM, PCM, TCM ECM EDM EBM LBM IBM PAM
  • 10. [1] CLASSIFICATION OF VARIOUS MANUFACTURING (Continued) Joining Or Consolidation Or Fabrication Processes [For assembling the various component s of a product] Joining Processes Advanced Welding Techniques: EBW, LBW, USW Welding of Plastics (only for Thermoplastics) : USW, LBW, Friction/spin Welding Vibration Welding Friction stir welding Hot-plate welding Hot-gas welding Implant welding Infrared welding Micro-wave welding Mechanical Bonding Atomic Bonding Tempor - ary Permanent or semi- permanent Solid state welding Liquid state or Fusion Welding Solid/ Liquid state Electrical Chemical Thread joints Rivets, Stitches, Staples, Shrink-fits, Friction, Forge, Diffusion welding, Cold Welding: Pressure, Explosive, Ultrasonic Welding Arc welding: Using Consumable Electrode SMAW , GMAW , FCAW, SAW; Those using Non- consumable Electrode: GTAW, PAW, SW . Resistance welding: RSW, RSEW, RPW. Induction welding Gas welding: OAW , and PGW, Thermit welding Brazing, Soldering, and Adhesive bonding
  • 11. [1] CLASSIFICATION OF VARIOUS MANUFACTURING (Continued) Basic Nature Traditional or Conventional Processes Advanced or Unconventional Processes Heat Treatment or Bulk Property Enhancing Processes [To modify the bulk properties.] HARDENING TECHNIQUES SURFACE HARDENING (ie Selective Heating) Processes: Flame Hardening, and Induction Hardening Laser Beam Hardening and Electron Beam Hardening CASE HARDENING (ie Surface Chemistry Altering) Processes: Carburizing (pack, gas, and liquid type), Nitriding, Cyaniding or Carbonitriding. Additional Layer Depositing: Ionitriding, Ion Carburizing, Ion Plating, and Ion Implantation CRACK REDUCTION TECHNIQUES: Austempering, Martempering / Marquenching DUCTILITY, TOUGHNESS, and MACHINABILITY changing processes: Annealing (Full and Process type), Normalizing, Tempering, Spheroidizing. STRENGTHENING processes: Solid Solution Strengthening, Grain Size Refinement, Strain Hardening, Precipitation or Age Hardening, Dispersion Hardening, and Phase Transformation Hardening
  • 12. Basic Nature Traditional or Conventional Processes Advanced or Unconven tional Processes Finishing And Surface Treatment Processes [To modify the surface properties.] BURR REOMVAL: Grinding, Chamfering, Filing, Centrifugal and Spindle Finishing, Thermal- energy Deburring, Power Sanding, Power Brushing, and Mechanical Cleaning Processes as described below. For burr Removal: USM, AJM, WJM, AWJM, AFM, CHM, ECDE MECHANICAL CLEANING and FINISHING: Abrasive Cleaning, Barrel Finishing OrTumbling,Vibratory Finishing, Belt Sanding,Wire Brushing, Buffing, Electro-polishing. CHEMICAL CLEANING: Vapor Degreasing, Acid Pickling, Alkaline, Solvent,And Ultrasonic Cleaning. COATING TECHNIQUES COATING (Liquid/Gas Deposition): Painting, Chemical Conversion Coating, Hot Dip Coating, Electro-plating, Anodizing, Electroless or Autocatalytic Plating, Mechanical Plating, Porcelain Enameling. CLADDING (Solid deposition) VAPORIZED METAL COATING Physical Vapor Deposition (PVD): Vacuum Metallizing, Sputtering, Ion Plating Chemical Vapor Deposition (CVD) [1] CLASSIFICATION OF VARIOUS MANUFACTURING (Continued)
  • 13. Types of AMPs  Basic AMPs: 15 (8 Mechanical + 1 Electrochemical + 1 Chemical + 5 Thermal)  Derived AMP: Modification of Basic AMP to Meet Specific Objectives Derived AMPs from ECM Electro Stream Drilling (ESD) Shaped Tube Electro Machining (STEM) Electrolytic Jet Drilling (EJD) Derived AMP from CHM Photo Chemical Machining (PCM) Derived AMP from EDM Wire Electro Discharge Machining (WEDM) Derived AMP from AFM Centrifugal Force Assisted Abrasive Flow Machining (CFA-AFM)  Hybrid Machining Processes (HMPs)
  • 14. [1] Concept of HMP Combining Either Two or More than Two AMPs or AMP + Conventional Machining Process [2] When to Conceptualize and Develop an HMP ?  To Simultaneously Exploit the Potentials and Capabilities of the Constituent Processes; and / or  To Minimize the Adverse Effects Induced When a Constituent Process is Used Independently  Generally, Development of an HMP is either Material or Shape Application Specific Hybrid Machining Processes (HMPs)
  • 15. HMPs are Gaining Considerable Attraction  Meet Some of the Ultraprecision Machining Requirements  Meet High Productivity Requirements for the Components Made of Advanced DTM Materials  Meet the Challenging Stringent Design Requirements  Meet Extreme Surface Quality andTolerance Requirement Types of HMPs [Can be Classified Into Two Major Categories (Kozak & Rajurkar, 2001)]  Processes in which Constituent Processes are Directly Involved in Material Removal;  Processes in which only ONE of the Participating Processes Directly Removes the Material while others Only ASSIST in Removal By Changing the Conditions of Machining in a Positive Manner  Most of the HMPs are in their Inception and Development Phase  Sustained Research is Required to Transform HMPs into a Matured Manufacturing Technology and forTheir Successful Commercialization and Industrial Applications
  • 16. Process Combining Energy Sources Mechanism of Material Removal Tool Transfer Media Conventional Machining + Electrochemical AMP ECH Electrochemical + Mechanical Electrochemical Dissolution and Abrasion Abrasive Sticks Electrolyte ECG Electrochemical + Mechanical Electrochemical Dissolution and Abrasion Abrasive Wheel Electrolyte ECAG Electrochemical + Mechanical Electrochemical Dissolution and Abrasion Metal Bonded Abrasive Wheel Electrolyte Conventional Machining + Thermal AMP AEDM Mechanical + Thermal Melting, Evaporation and Abrasion Loose Abrasive Particles Dielectric EDAG Mechanical + Thermal Melting, Evaporation and Abrasion Metal Bonded Abrasive Wheel Dielectric EDDG Mechanical + Thermal Melting, Evaporation and Abrasion Diamond wheel Dielectric LAT Mechanical + Thermal Shearing and Heating Turning Tool Air PAT Mechanical + Thermal Shearing and Heating Turning Tool Air LAE Chemical + Thermal Chemical Dissolution and Heating Mask Etchant Conventional Machining + Mechanical AMP RUM Mechanical + Ultrasonic Vibration Abrasion Sonotrode having Diamond Abrasives Coolant UAT Mechanical + Ultrasonic Vibration Shearing Turning Tool Air Examples of HMPs [Conventional Machining + AMP]
  • 17. Process Combining Energy Sources Mechanism of Material Removal Tool Transfer Media Electrochemical + Thermal ECSM or ECAM Electrochemical + Thermal Melting and/Or Evaporation Electrode Electrolyte LAECM Electrochemical + Thermal Electrochemical Dissolution and Heating Electrode Electrolyte Electrochemical + Mechanical USECM Electrochemical + Ultrasonic Vibration Electrochemical Dissolution Sonotrode Electrolyte ECMAF Electrochemical + Mechanical Electrochemical Dissolution + Abrasion Abrasives Electrolyte Mechanical + Thermal USEDM Thermal + Ultrasonic Vibration Melting and Evaporation Sonotrode Dielectric USLBM Thermal + Ultrasonic Vibration Melting and Evaporation Laser Beam Air Two Mechanical AMPs MRAFF Two Mechanical AMPs Shearing Abrasives MR Fluid More than Two AMPs BEDMM Electrochemical + Mechanical + Thermal Electrochemical, Melting and Mechanical Rupture Rotating Metal Brush Water Glass Solution In Water Examples of HMPs [Two or More AMPs]
  • 18. Typical Examples of Parts Developed by AMPs Figure:1Typical parts made by electrochemical machining. (a) Turbine blade made of nickel alloy of 360 HB. Note the shape of the electrode on the right. (b) Thin slots on a 4340-steel roller-bearing cage. (c) Integral airfoils on a compressor disk. MALE FEMALE PRECISION WIRE EDM Design Made using 3D Printing
  • 19. Important Characteristics of AMPs Process performance is independent of Workpiece Material properties such as hardness.Toughness, ductility, brittleness etc. Process Performance highly depends upon the thermal, electrical, magnetic and chemical properties of the workpiece material Process utilizes different types of source energy i.e. Mechanical, Thermal, Electrical and Chemical in its direct form Usually AMPs Possesses lower material removal rate as compared to conventional processes but in turns AMPs provide high quality parts Initial investment cost of setting an AMP is high due to costly machine tools and high operating costs
  • 20. Classification of UNconventional machining Processes • Mechanical mechanical erosion of work material by a high velocity ‑ stream of abrasives or fluid (or both) • Electrical electrochemical energy to remove material (reverse of ‑ electroplating) • Thermal – thermal energy applied to small portion of work surface, causing that portion to be fused and/or vaporized • Chemical – chemical etchants selectively remove material from portions of workpart, while other portions are protected by a mask
  • 21. Mechanical Energy Processes • Ultrasonic machining • Water jet cutting • Abrasive water jet cutting • Abrasive jet machining • Abrasive flow machining
  • 22. Ultrasonic Machining • Ultrasonic vibration (20,000 Hz) of very small amplitudes (0.04-0.08 mm) drive the form tool (sonotrode) of ductile material (usually soft steel) • An abrasive slurry is flowed through the work area • The workpiece is brittle in nature (i.e. glass) • The workpiece is gradually eroded away.
  • 23. Ultrasonic Machining (USM) • Abrasives contained in a slurry are driven at high velocity against work by a tool vibrating at low amplitude and high frequency • Tool oscillation is perpendicular to work surface • Abrasives accomplish material removal • Tool is fed slowly into work • Shape of tool is formed into part
  • 24. USM Applications • Hard, brittle work materials such as ceramics, glass, and carbides • Also successful on certain metals, such as stainless steel and titanium • Shapes include non-round holes, holes along a curved axis • “Coining operations” - pattern on tool is imparted to a flat work surface
  • 25. • Uses high pressure, high velocity stream of water directed at work surface for cutting Water Jet Cutting (WJC)
  • 26. WJC Applications • Usually automated by CNC or industrial robots to manipulate nozzle along desired trajectory • Used to cut narrow slits in flat stock such as plastic, textiles, composites, floor tile, carpet, leather, and cardboard • Not suitable for brittle materials (e.g., glass)
  • 27. WJC Advantages • No crushing or burning of work surface • Minimum material loss • No environmental pollution • Ease of automation
  • 28. Abrasive Water Jet • High pressure water (20,000-60,000 psi) • Educt abrasive into stream • Can cut extremely thick parts (5-10 inches possible) • Thickness achievable is a function of speed • Twice as thick will take more than twice as long • Tight tolerances achievable • Current machines 0.002” (older machines much less capable ~ 0.010” • Jet will lag machine position, so controls must plan for it
  • 29. • High velocity stream of gas containing small abrasive particles Abrasive Jet Machining (AJM)
  • 30. AJM Application Notes • Usually performed manually by operator who aims nozzle • Normally used as a finishing process rather than cutting process • Applications: deburring, trimming and deflashing, cleaning, and polishing • Work materials: thin flat stock of hard, brittle materials (e.g., glass, silicon, mica, ceramics)
  • 31. Electrochemical Machining Processes • A group of processes in which electrical energy is used in combination with chemical reactions to remove material • Reverse of electroplating • Work material must be a conductor • Processes: • Electrochemical machining (ECM) • Electrochemical deburring (ECD) • Electrochemical grinding (ECG)
  • 32. • Material removal by anodic dissolution, using electrode (the tool) in close proximity to work but separated by a rapidly flowing electrolyte Electrochemical Machining (ECM)
  • 33. ECM Applications • Die sinking - irregular shapes and contours for forging dies, plastic molds, and other tools • Multiple hole drilling - many holes can be drilled simultaneously with ECM • Holes that are not round • Rotating drill is not used in ECM • Deburring
  • 34. • Adaptation of ECM to remove burrs or sharp corners on holes in metal parts produced by conventional through hole drilling ‑ Electrochemical Deburring (ECD)
  • 35. • Special form of ECM in which grinding wheel with conductive bond material augments anodic dissolution of metal part surface Electrochemical Grinding (ECG)
  • 36. Applications and Advantages of ECG • Applications: • Sharpening of cemented carbide tools • Grinding of surgical needles and other thin-wall tubes, and fragile parts • Advantages: • Deplating responsible for 95% of metal removal • Because machining is mostly by electrochemical action, grinding wheel lasts much longer
  • 37. Thermal Energy Processes- Overview • Very high local temperatures • Material is removed by fusion or vaporization • Physical and metallurgical damage to the new work surface • In some cases, resulting finish is so poor that subsequent processing is required ©2013 John Wiley & Sons, Inc. M P Groover, Principles of Modern Manufacturing 5/e
  • 38. Thermal Energy Processes • Electric discharge machining • Electric discharge wire cutting • Electron beam machining • Laser beam machining • Plasma arc machining
  • 39. Electric Discharge Processes • Metal removal by a series of discrete electrical discharges (sparks) causing localized temperatures high enough to melt or vaporize the metal • Can be used only on electrically conducting work materials • Two main processes: • Electric discharge machining • Wire electric discharge machining
  • 40. • (a) Setup of process and (b) close up view of gap, showing discharge and metal ‑ removal Electric Discharge Machining (EDM)
  • 41. Work Materials in EDM • Work materials must be electrically conducting • Hardness and strength of work material are not factors in EDM • Material removal rate depends on melting point of work material
  • 42. EDM Applications • Tooling for many mechanical processes: molds for plastic injection molding, extrusion dies, wire drawing dies, forging and heading dies, and sheetmetal stamping dies • Production parts: delicate parts not rigid enough to withstand conventional cutting forces, hole drilling where hole axis is at an acute angle to surface, and machining of hard and exotic metals
  • 43. • Special form of EDM that uses a small diameter wire as electrode to cut a narrow kerf in work Wire EDM
  • 44. Operation of Wire EDM • Work is fed slowly past wire along desired path • Similar to a bandsaw operation • CNC used for motion control • While cutting, wire is continuously advanced between supply spool and take up spool to maintain a constant diameter ‑ • Dielectric required, using nozzles directed at tool work interface or ‑ submerging workpart
  • 45. • Definition of kerf and overcut in electric discharge wire cutting Wire EDM
  • 46. Wire EDM Applications • Ideal for stamping die components • Since kerf is so narrow, it is often possible to fabricate punch and die in a single cut • Other tools and parts with intricate outline shapes, such as lathe form tools, extrusion dies, and flat templates
  • 47. Wire EDM Application • Irregular outline cut from a solid slab by wire EDM (photo courtesy of Makino).
  • 48. Laser Beam Machining • Lasers are high intensity focused light sources • CO2 • Most widely used • Generally more powerful that YAG lasers • Cutting operations commonly • Nd:YAG (Neodymium ions in an Yttrium Aluminum Garnet) • Less powerful • Etching/marking type operations more commonly • Limited in depth of cut (focus of light) • Would limit workpiece to less than 1 inch (< ½” typically)
  • 49. WORKING OF IBM Process: • An ion source generates ions, usually argon or other inert gases, and accelerates them to high velocities. • The ion beam is directed toward the workpiece, where ions collide with the material and cause atoms to dislodge, effectively "sputtering" the material away. • IBM is a non-contact process, so there is minimal thermal impact on the material. Materials Machined: •Ideal for hard materials like ceramics, metals, semiconductors, and optical glass. •Used in applications where chemical reactions might alter the material’s properties.
  • 50. Mechanism of Material Removal In Ion Beam Machining  Particle beam consisting of ionized atoms i.e. ions .  A stream of ions of an inert gas, such as argon or metal such as gallium is accelerated in a vacuum by high energies and directed toward a solid work-piece.  Ion beam knocks off atoms from workpiece by transferring kinetic energy and momentum to atoms on the surface of the object,  Sputtering off: knocking out atoms from the work-piece surface through the transfer of kinetic energy from the incident ion to the target atoms  Removal of atoms occurs when the energy transferred exceeds the binding energy
  • 51. It is a process that uses a high-velocity jet of ionized gas to cut and remove material from a workpiece: •How it works A plasma torch generates a high-temperature plasma jet by passing gas through an electric arc between a cathode and anode. The plasma jet melts and displaces the material from the workpiece. •Temperature The plasma jet can reach temperatures of 11,000– 30,000°C. Plasma arc machining (PAM)
  • 52. •Materials PAM is often used to cut electrically conductive materials like steel, aluminum, brass, and copper. •Applications PAM is used in fabrication and welding shops, automotive repair, industrial construction, and salvage operations. •Gases The gas used depends on the material being cut. For example, a mixture of argon and hydrogen can be used for thicker stainless steel or aluminum, while a mixture of hydrogen and nitrogen or methane and nitrogen can be used for thinner stainless steel. •Advantages PAM is known for its high speed, precision cuts, and low cost of operation. Plasma is a superheated, electrically ionized gas that is the fourth state of matter, along with solid, liquid, and gas. It is highly conductive and very bright.
  • 53. Hybrid Machining Processes • Hybrid production/manufacturing means the combination of processes/machines in order to produce parts in a more efficient and productive way. • A general objective of hybrid manufacturing is the ‘‘1 + 1 = 3’’effect, meaning that the positive effect of the hybrid process is more than the double of the advantages of the single processes. • Hybrid can have several meanings: combination of different active energy sources which act at the same time in the processing zone (e.g. laser assisted turning); processes which combine process steps that are usually performed in two or more process steps
  • 54. Classification of hybrid machining processes • Combined or mixed-type processes in which all constituent processes are directly involved in the material removal. • Assisted-type processes in which only one of the participating processes directly remove material, while the other only assists in removal by having a positive effect on the conditions of machining
  • 55. Assisted hybrid processes 1. Vibration assisted hybrid machining processes: • Vibration assisted grinding is a rather new technology where a superposition of conventional grinding and a vibration (most often in the ultrasonic range) is established.
  • 56. Vibration assisted EDM • In micro-EDM process flushing conditions and discharge gap state have been identified as main influences. Improved flushing strategies and optimized discharge gap control circuits have led to great improvements. • The periodic relative movement between tool and workpiece causes a flow of the dielectric and an agitation of the debris particles in the dielectric medium. Due to this phenomenon, a settlement of debris on the bore ground and the agglomeration of particles are reduced and the state of the gap is equalized.
  • 57. Vibration assisted EDM In vibration assisted EDM, an additional relative movement is applied in the system tool electrode, work piece and dielectric fluid in order to increase the flushing efficiency, resulting in a higher material removal rate and better process stability.
  • 58. Ultrasonic-Assisted ECM (USECM) • Electrochemical dissolution and the formation of a passivating oxidelayer occur on the work piece surface by ion formation and movement within the electrolyte producing a high intensity current flow. • The passivating layer is then removed by these ultrasonically accelerated abrasives that impact the work piece surface. This process also helps to maintain a constant inter-electrode gap.
  • 59. 2. Heat-Assisted HMPs • The use of an external heat source improves the machinability by minimizing the machining forces, improving the work surface, integrity and enhancing the tool life. This heat source may be in the form of a laser beam, electron beam, plasma beam, high-frequency induction or electric current etc. • Laser-assisted machining is one of the important and most widely used category of the heat- assisted HMPs. • Laser-assisted HMPs are of two types: • Laser-assisted mechanical machining: in which, a laser is used to heat the work piece ahead of the cutting tool during conventional machining processes such as turning, milling and grinding. • Laser-assisted advanced machining: where laser assistance enhances the material removal in electrolytic dissolution and electro discharge-based AMPs.
  • 60. I-Laser assisted turning • In this process, the main material removal mechanism is still the one occurring in conventional cutting, but the laser action softens the work piece material, so machining of high alloyed steels or some ceramics becomes easier. • The laser beam is directly focused in front of the cutting tool, resulting in easier machining and higher process performance.
  • 61. II-Laser assisted ECM (LAECM) The primary role of a laser in ECM is to improve the localization of the dissolution process. The main mechanism of material removal in laser-assisted ECM (LAECM) is enhanced by electrolytic dissolution because of an improved thermal activation brought upon by a focused laser beam. Additionally, it also helps in removing the passivating metallic oxide layers formed on the workpiece due to the evolution of oxygen at the anode during the electrolysis process.
  • 62. III-Laser-Assisted EDM (LAEDM) • EDM drawbacks: Lengthy machining times and high tool wear • Laser drawbacks: Formation of a recast layer and heat-affected zones (HAZ) and low surface quality of the work piece. • Solution: • Hybridization of LBM and EDM as LAEDM addresses their respective disadvantages. LAEDM is generally used in micro-machining applications for reducing production time and eliminating the recast layer and HAZ caused by laser ablation
  • 63. Laser-Assisted EDM (LAEDM) • A short-pulsed laser beam capable of producing high ablation rates is used to roughly pre- machine the basic part features (i.e. groove, hole, cavity). This is subsequently followed by micro- EDM within a suitable dielectric to remove the surface defects caused by the thermal effects of laser ablation and to finish the feature
  • 64. 3. Magnetic field assisted machining processes • Magnetic field-assisted HMPs rely on the enhancement of the primary machining/finishing process by the addition (assistance) of magnetic field with the aim to improve work piece surface quality and material removal rate. • Magnetic field-assisted EDM (MAEDM) • Magnetic field-assisted abrasive flow machining (MAAFM) • I. Magnetic Field-Assisted EDM (MAEDM) • Debris accumulation in the machining zone that adversely affects performance and efficiency has always been a perennial problem in EDM. • Adding magnetic field enhances the process stability and increases the efficiency of the EDM component by effective removal of machining debris from the machining zone.
  • 65. 1.Magnetic Field-Assisted EDM (MAEDM) The introduction of the magnetic field exerts a magnetic force perpendicular to the electrode’s motion. As a result, debris particle in the machining zone is subjected both to a magnetic force and to a centrifugal force. The resultant force which is the vector summation of the magnetic and centrifugal forces ensures effective and rapid flushing of debris particles.
  • 66. 2.Magnetic field-assisted abrasive flow machining Magnetic field-assisted abrasive flow machining (MAAFM) is an important hybrid AFM process where the assistance of a magnetic field provides the means of controlling the cutting forces and consequently the outcome of the process includes higher surface finish and finishing rate. This process is capable of producing a surface roughness as small as 8-10 nm.
  • 67. 4.External Electric Field-Assisted machining • Laser Percussion Drilling for Highly Reflective Metals • Laser percussion drilling has gained great attention in the industry due to its wide industrial applicability and usage in processing of various materials, such as metals, glass, and ceramics. • Laser percussion drilling is also characterized by a noncontact machining process, smaller beam spot size, high operating speeds, great flexibility, and accuracy. However, it is difficult to apply laser percussion drilling to highly reflective target surfaces, such as aluminium, which reflect the optical energy and dramatically reduce the processing efficiency • This drawback lengthens the drilling time, increasing the cost of the process and decreasing the yield. • Using the electric field influences the behaviour of the plasma plume during laser percussion drilling. The depths of the drilled holes, obtained in the presence of applied electric field, are deeper than those obtained in the normal case. These results are due to the effect of the electric force by which the plume particle could be accelerated in the electric field
  • 68. Femto second laser micromachining of silicon with an external electric field • Machining of silicon wafers with fs lasers the debris was formed as a result of aggregation of small particles such as atoms or atomic clusters on the substrate surface instead of large-scale droplets or fragments, which are commonly observed with nanosecond lasers. • In order to prevent particles from redepositing onto the Si surface an electric field during the fs laser machining is applied. It is assumed that the charged ions in the plasma cloud would be attracted to the electrodes fs laser micromachining of Si without the external
  • 69. Combined hybrid machining • Combined or mixed HMPs are those processes in which two or more energy sources/tools/mechanisms are combined and have a synergetic effect on the material removal process. They can further be categorized as electrochemical HMPs and thermal HMPs. • Electrochemical Hybrid Machining Processes (ECHMP) • ECM offers many advantages, namely process performance being independent of mechanical properties of the workpiece material production of largely stress-free surface good surface finish and integrity higher productivity due to higher MRRs
  • 70. Electrochemical Hybrid Machining Processes (ECHMP) • Limitations: Passivation of work piece surface by non-conducting metal oxide layer formation due to the evolution of oxygen gas at the anode applicability to only electrically conducting materials corrosion of machining elements and surroundings due to the use of an electrolyte chemical damage caused to work piece surface the dependence of accuracy on the inter-electrode gap which requires efficient flushing
  • 71. Need of ECHMP • Conventional finishing processes such as grinding, mechanical honing, buffing and superfinishing are inexpensive and give good surface quality, but the use of abrasives imparts some inherent limitations such as high tool wear; low productivity and mechanical damage to the finished surface. • Solution: • Combine ECM with some conventional machining/finishing or AMP to develop and electrochemical HMP (ECHMP)
  • 72. Electrochemical Grinding (ECG) • ECG is the result of hybridizing ECM with the abrasive action of conventional grinding to machine hard and fragile electrically conducting materials efficiently, economically and productively without affecting the useful properties of these materials. • ECG offers accurate and largely surface residual stress-free machining with no burrs and heat affected zone (HAZ) and, therefore, little distortion
  • 73. Equipment and Working Principle The non-conducting abrasive particles protrude just beyond the surface of the bonding material of the wheel helping to maintain a constant inter-electrode gap and act as spacers. Bonding materials such as copper, brass, nickel or copper impregnated resin are commonly used for the manufacture of metal-bonded grinding wheels. Functions of abrasive particles: to maintain the electrical insulation between anode workpiece and cathode. continuously remove any passive layer that may be formed on the workpiece surface by chemical reaction To determine workpiece shape and size
  • 74. Three distinct zones in ECG process Zone I, the material removal is purely due to electrochemical dissolution In Zone II, the gas bubbles in the gap yield higher MRRs. Chemical or electrochemical reaction may result in the formation of a passive layer on the workpiece surface. The abrasive particles not only remove material from the work surface in the form of chips but also remove the non-reactive oxide layer. Zone III, the material removal is done completely by electrochemical dissolution. This zone starts at the point where the wheel lifts just beyond the work surface. This zone contributes by removal of burrs that formed on the workpiece in zone II
  • 75. EDM Combined with Conventional Machining • Electric Discharge Grinding (EDG): EDG is a thermal HMP An electrically conductive grinding wheel is used as a tool electrode. Material removal occurs due to the electro discharge action. Abrasive component of the process ensures effective flushing which results in improved material removal rate and enhanced surface finish as compared to the conventional EDM process
  • 76. Electric Discharge Diamond Grinding (EDDG) ) mechanism of material removal in EDAG A metal-bonded grinding wheel with embedded abrasive particles is used to enhance the machining productivity and surface finish. Al2O3, SiC and CBN are commonly used abrasive in this process. When diamond is used as abrasive, this process is known as electric discharge diamond grinding (EDDG).
  • 77. Electrochemical Discharge Machining (ECDM) • ECDM is a combination of electric discharge machining (EDM) and electrochemical machining (ECM). Used for the machining of electrically non-conducting materials such as insulating ceramics, glass, polymers etc. • A complex combination of electrolytic dissolution and spark erosion. Schematic of ECDM process Process mechanism of ECDM
  • 78. Electrochemical Discharge Grinding (ECDG) Electrochemical discharge grinding (ECDG) hybridizes spark erosion, electrolytic dissolution and mechanical abrasion to machine electrically conductive workpieces Dissolution occurs at the workpiece (anode) due to the electrochemical reaction A passivating oxide layer is also formed on the work surface during the electrochemical reaction. Subsequent electro-erosion phase, the spark discharges de- passivate the oxide layer Enhances the effectiveness of the electrochemical dissolution and thereby improves the workpiece material removal rate.
  • 79. Additive Manufacturing Additive Manufacturing (AM) refers to a process by which digital 3D design data is used to build up a component in layers by depositing material. (from the International Committee F42 for Additive Manufacturing Technologies, ASTM)..
  • 82. Medical Applications Hip socket, Ala Ortho, Italy, made on Arcam machine Laser Sintered Hearing Aids, EOS/Materialise
  • 84. Food Printers MIT Media Lab FabCafe in the Shibuya, Tokyo offers custom-printed chocolate, that resemble a customer’s face. It’s done with 3D printing technology “Eat Your Face Machine” (EYFM) is a 3D printer developed by David Carr and the MIT Media Lab
  • 85. AM : For household Products
  • 87. AM Benefits : Weight Reduction
  • 88. AM Benefits : Complexity for free
  • 89. AM : Customized Medical Equipments
  • 92. AM processes are classified into seven categories 1) Vat Photopolymerisation/Steriolithography 2) Material Jetting 3) Binder jetting 4) Material extrusion 5) Powder bed fusion 6) Sheet lamination 7) Directed energy deposition
  • 93. Vat photopolymerization/Steriolithography • Laser beam traces a cross-section of the part pattern on the surface of the liquid resin • SLA's elevator platform descends • A resin-filled blade sweeps across the cross section of the part, re-coating it with fresh material • Immersed in a chemical bath Stereolithography requires the use of supporting structures
  • 94. Material Jetting • Drop on demand method • The print head is positioned above build platform • Material is deposited from a nozzle which moves horizontally across the build platform • Material layers are then cured or hardened using ultraviolet (UV) light • Droplets of material solidify and make up the first layer. • Platform descends • Good accuracy and surface finishes
  • 95. Binder Jetting • A glue or binder is jetted from an inkjet style print head • Roller spreads a new layer of powder on top of the previous layer • The subsequent layer is then printed and is stitched to the previous layer by the jetted binder • The remaining loose powder in the bed supports overhanging structures
  • 96. Material Extrusion/FDM • Fuse deposition modelling (FDM) • Material is drawn through a nozzle, where it is heated and is then deposited layer by layer • First layer is built as nozzle deposits material where required onto the cross sectional area. • The following layers are added on top of previous layers. • Layers are fused together upon deposition as the material is in a melted state.
  • 97. Powder Bed Fusion • Selective laser sintering (SLS) • Selective laser melting (SLM) • Electron beam melting (EBM) No support structures required PROCESS • A layer, typically 0.1mm thick of material is spread over the build platform. • The SLS machine preheats the bulk powder material in the powder bed • A laser fuses the first layer • A new layer of powder is spread. • Further layers or cross sections are fused and added. • The process repeats until the entire model is created.
  • 98. Sheet Lamination • Metal sheets are used • Laser beam cuts the contour of each layer • Glue activated by hot rollers PROCESS 1. The material is positioned in place on the cutting bed. 2. The material is bonded in place, over the previous layer, using the adhesive. 3. The required shape is then cut from the layer, by laser or knife. 4. The next layer is added.
  • 99. Directed Energy Deposition • Consists of a nozzle mounted on a multi axis arm • Nozzle can move in multiple directions • Material is melted upon deposition with a laser or electron beam PROCESS 1. A4 or 5 axis arm with nozzle moves around a fixed object. 2. Material is deposited from the nozzle onto existing surfaces of the object. 3. Material is either provided in wire or powder form. 4. Material is melted using a laser, electron beam or plasma arc upon deposition. 5. Further material is added layer by layer and solidifies, creating or repairing new material features on the existing object.