Micro mach
Download as PPT, PDF1 like988 views
This document discusses recent trends in non-conventional micromachining techniques. It describes several methods such as electrochemical micro-machining (EMM), micro-electrodischarge machining (MEDM), laser micro-machining (LMM), ultrasonic micro-machining (USM), and chemical micro-machining (CMM). For each method, it explains the basic principles, micro-machining processes, applications for micro components, and potential for future development at the nanoscale. The document also explores emerging nanomachining techniques using tools like atomic force microscopes and various top-down and bottom-up fabrication processes.
Micro mach
- 1. RECENT TRENDS OF “NON-CONVENTIONAL MICROMACHINING” RECENT TRENDS OF “NON-CONVENTIONAL MICROMACHINING” Taha Ali El-Taweel Production Engineering and Mechanical Design Faculty of Engineering, Shebin El-Kom, Menoufiya University Taha Ali El-Taweel Production Engineering and Mechanical Design Faculty of Engineering, Shebin El-Kom, Menoufiya University By
- 2. INTRODUCTION Electrochemical micro-machining (EMM) Through-maskless - Through-mask Micro-electrodischarge machining (MEDM) Laser micro-machining (LMM) Mask projection techniques - Direct writing techniques Micro-ultrasonic machining (MUSM) Chemical- micro machining (CMM) Dry chemical etching - Wet chemical etching FUTURE POTENTIAL LAYOUT OF THE PRESENTATIONLAYOUT OF THE PRESENTATION
- 3. Thermal Action - EDM - LBM - IBM Mechanical Action - USM - WJM - AJM INTRODUCTIONINTRODUCTION The need for fabricating parts from hardened high- strength and heat-resistant metals and alloys has created difficult machining problems for industry. To meet these problems, non-conventional machining methods have been developed. (no mechanical force) Chemical Action Chemical Milling Electrochemical Action - ECM Non-conventional Machining
- 4. Micro-machiningMicro-machining The term micro-machining refers to material removal of small dimensions that range from several microns to one millimeter.
- 5. NON-CONVENTIONAL MICROMACHININGNON-CONVENTIONAL MICROMACHINING • Electrochemical micro-machining (EMM) • Micro-electrodischarge machining (MEDM) • Laser micro-machining (LMM) • Ultrasonic micro-machining (USMM) • Chemical micro-machining (CMM) The unit of removal can be of the order of atomic quantities through;
- 6. Electrochemical machining (ECM)Electrochemical machining (ECM) Electrochemical machining (ECM) Ion exchange is the metal removal mechanism. - Reverse of electroplating - Workpiece must be electrically conductive - Electrolyte acts as a current carrier - High rate of electrolyte movement; washes metal ions. - ECM for the production of gas turbine compressor blades Principle of ECM machining
- 7. EMM through-maskless EMM through-mask Electrochemical micro-machining - Capillary drilling - MEJM - One-sided EMM - Two-sided EMM Electrochemical micro-machining (EMM)Electrochemical micro-machining (EMM) Requires highly localized material removal induced by the impingement of a fine electrolytic jet.
- 8. Electrochemical micro-machining (EMM)Electrochemical micro-machining (EMM) EMM through-masklessEMM through-maskless Micro electrochemical jet machining (MEJM) Capillary drilling workpiece (anode) nozzle diameter electrolyte jet (cathode) Insulation glass tube platinum (cathode) workpiece (anode) electrolyte MEJM Capillary drilling Removes material by using an electrolyte jet from a small nozzle, which works as cathode without advancement of the jet. Fine cathode tool in the form of a capillary that is advanced at constant rate towards the workpiece.
- 9. EMM through-maskEMM through-mask Involves selective metal dissolution from unprotected areas of a one- or two-sided photoresist-patterned workpiece. The sample is held in a stationary holder while the multi-nozzle cathode, which is attached to the table, moves at a constant speed facing the sample One-sided Localized dissolution induced by scanning two cathode assemblies over a vertically held work-piece providing movement of the electrolyte Two-sided One-sided EMM Two-sided EMM Electrochemical micro-machining (EMM)Electrochemical micro-machining (EMM)
- 10. Fabrication of micro-electronic components Ink-jet nozzle plates Metal masks Micro-hole drilling Micro-surface production Ink-jet nozzle Photograph of micro holes Cylindrical micropin DC current Pulse current EMM applicationsEMM applications Micro gear pattern
- 11. Machining with ultra- short voltage pulses EMM applicationsEMM applications Micro grooves by wire ECM
- 12. Electrodischarge machining (EDM)Electrodischarge machining (EDM) Electrical Discharge Machining (EDM) is a non-conventional machining technique in which the material is removed by the erosive action of electrical discharges (sparks) provided by a generator. Benefits Widely accepted production technology - 2% of worldwide machining. High surface finishes Hardness of material not a concern Odd/Delicate shapes easier to produce Small holes easy to produce Heat treatment usually unnecessary Drawbacks Slower machining time Surface integrity effects
- 13. Electrodischarge machining (EDM)Electrodischarge machining (EDM) EDM Process Mechanism
- 14. Different Types of EDMDifferent Types of EDM Die-sinking EDM Wire EDM Machinable material » electrically conductive » semiconductor materials Schematic illustration of EDM system Principle of WEDG Can be made » micro shafts » micro holes » other complex shapes
- 15. Micro-electrodischarge machining (MEDM)Micro-electrodischarge machining (MEDM) It is required for micro-machining to maintain the energy of a single discharge in the order of 10-6 J to10-7 J E =1/2 (C + C') V 2 Reducing the discharge energy: » By reducing the discharge voltage » By reducing the total capacitance (C + C')Effective discharge control can be achieved, by Controlling parameters: » Discharge current » Open circuit voltage » Off-time » Polarity of electrode Description of eroding pattern and overlapping pattern of discharge
- 16. MEDM applicationsMEDM applications . MEDM of ceramics Cross-sectional shape on the TiN coating and the EDMed surface Micro-electrodes for and micro-pins Fabrication of Micronozzle Micro-hole drilling positive polarity negative polarity
- 17. MEDM applicationsMEDM applications Pagoda machined by micro wire EDM
- 18. Laser machining (LM)Laser machining (LM) – Heat treatment – Welding – Ablation – Deposition – Etching – Focused beam milling Laser applicationsLaser applications Setup of the laser micro-machining Highly focused optical energy of Laser is used to melt and evaporate workpiece portions in a controlled manner. - Refectivity and thermal conductivity of workpiece are important - Widely used in automotive and electronics industries due to its accuracy, reproducibility, flexibility, ease of automation.
- 19. LMM applicationsLMM applications » Micro-machining of electrostatic electron lenses » Ink-jet printer nozzles » Micro-hole drilling » Micro-channels produced by mask projection » Manufacturing of 3D structures Example geometries in WC/Co Ink-jet printer nozzles Micro-channelsMicro-holes
- 20. Ultrasonic machining (USM)Ultrasonic machining (USM) Ultrasound - above 20 kHz, can be generated using peizoelectric or magnetostictive effects - A formed tool, with the shape of the cavity to be machined is made to vibrate against the workpiece surface and between the two are placed abrasive particles (slurry). - The material is removed in the form of grains by shear deformation, brittle fracture of work material; and by impact, cavitation and chemical reaction Principle of USM
- 21. Micro-ultrasonic machining (MUSM)Micro-ultrasonic machining (MUSM) Micro USM procedure MUSM toolsMUSM tools The WEDG/EDM combination is used to generate co-axial micro-tool first, which MUSM of brittle materials carried out Non-thermal, non-chemical and thus can produce a high-quality surface finish The machining procedure of microtool
- 22. MUSM applicationsMUSM applications » Micro-hole drilling» Micro-hole drilling The entrance The exit Micro air turbine.Center pin diameter 70 µm; rotor diameter 350 µm Finishing » Manufacturing of 3D s tructures » Manufacturing of 3D s tructures » Finishing EDMed parts» Finishing EDMed parts
- 23. Chemical machining (CM))Chemical machining (CM)) # Chemical milling # Chemical blanking # Photochemical blanking Used to make precise, microscopic holes microscopic grooves Material removal from the surface by controlled chemical dissolution using reagents, etchants- acids/alkalies » Dry chemical etching » Wet chemical etching
- 24. » Photoetching (lithography and isotropic etching) Chemical-micro machining (CMM)Chemical-micro machining (CMM)
- 25. CMM applicationsCMM applications Surface etching Electrochemical etching Chemical milling (surgical knife tool)
- 26. FUTURE POTENTIALFUTURE POTENTIAL The use of ultra-short pulses in EMM, MEDM & Laser to machine the widest choice of materials with very high quality. Studying the effect of machining parameters on surface integrity of micro component. Newest hybrid processes are suggested for micro- machining. • EMM with Laser Assistance (EMML) • EMM with MEDM • MUSM with EMM & MEDM
- 27. NanomachineryNanomachinery Nanofabrication as another way to get into the nano domain
- 28. NanomachineryNanomachinery Aerospace: Gyroscopes, transducers Biomedical: DNA detection/separation devices Molecular: sieves for protein sorting Electronics: Flexible (paper like) displays, nanowires Automotive: Accelerometers, pressure sensors Healthcare: Nanotherapeutic devices, catheters, infusion pumps, intrauterine products Industry Application ExamplesIndustry Application Examples
- 29. NanomachineryNanomachinery Scanning probe microscopes have been used for the machining of nanofeatures ranging from ~100 nm down to atomic dimensions Various approaches used are based on lithography, atomic and molecular level manipulation and material transfer, material modification by tip induced oxidation desorption hydrogenation or decomposition mechanical scratching of metals semiconductors and polymers. Nano Machining Using SPM Nano Machining Using SPM
- 30. NanomachineryNanomachinery Bottom-up processes Top-down processes Contact printing, Imprinting Template growth Spinoidal wetting/dewetting Laser trapping/tweezer Assembly and joining (Self- and directed assembly) Electrostatic (coatings and fibres) Colloidal aggregation. Lithography (E-beam, ion beam, Scanning probe, optical near field) Energy beam machining (Laser, electron beam, ion beam) Erosive processes (electrical, chemical, mechanical and ultrasonic) Typical nanomachining processes
- 31. NanomachineryNanomachinery Nano groove (1000 × 150 × 2.4 nm )machined in copper using atomic force microscope
- 32. Nanomachinery applicationsNanomachinery applications 5 μm deep spiral machined in Ni sheet Nanomachining by ECM (a) Tungsten Tool (b) Structure in Ni
Editor's Notes
- #7: *
- #9: *SEM micrographs were obtained for showing the fracture surfaces of specimens failed in air and argon. *The first graph (3.a) shows the fracture surface in air. It can be seen, some inclusions as well as number of secondary cracks. *The second graph (3.b) shows fracture surface in argon. It can be seen, the specimen has revealed more ductile manner, where primary and secondary striations are observed. *The third graph (8.a) shows with high magnification the fracture surface failed in air. Some crystallographic fracture modes were observed. The size and density of striations yielded on the fracture surfaces indicate the amount of plasticity associated with crack growth. *The forth graph (8.b) shows also with high magnification that the fracture surface failed in argon. It is clear, this surface exhibits more ductility than that tested in air.
- #10: *It can be seen that some cavities have nucleated very close to the crack tip and these nucleated cavities are linked together to form a very fine crack. *Cavity nucleation and linkage were obvious to be the dominant fracture mechanism in the very early stages while local strain softening were believed to be the dominant mechanism at the very late stages of the fracture lifetime. *It is suggested for bending fatigue testes that, the fatigue life of the specimens were consumed mostly by initiating a crack of a critical size and thus the propagation will consume short time duration.