structure and assessment
- 1. ME 730: Ultra-Precision Machining Course Structure Department of Mechanical Engineering Indian Institute of Technology, Bombay, Powai, MUMBAI – 400 076 Contact: Prof. Suhas Joshi: ssjoshi@iitb.ac.in, Phone: 7527 Prof. Suhas S. Joshi
- 2. 2 Course Structure • Introduction: Definition of ultra-precision machining; Taniguchi curves of evolution of accuracy in the twentieth century; definition of Nanotechnology; Positional accuracy of today’s manufacturing processes and equipment; Deviational and scattering errors in achieving nanometric resolution. • Atomic-bit and atomic cluster processing methods: Nano-mechanical, nano-physical and nano-chemical and –electrochemical processes, their capabilities and advantages. • Mechanism of nano-mechanical processing of atomic clusters: Processing stress, breaking stress and processing energy density; Concept of size effect in mechanical processing; thresholds of specific energy; Nano-machining, abrasive and adhesive processing, theories of nanometric processing of ductile and brittle materials, and polymers; Failure and fracture under uniform and localized loading; Atomic-bit processing and lattice defect density, theories of nano-indentation and scratching.
- 3. 3 • Mechanism of nano-physical and -chemical processing of atomic-bits: Scanning tunneling effect, directional photon, electron and ion beam processing, plasma surface processing, molecular beam processing; Principles of chemical and electro-chemical processing, equilibrium of chemical and electro-chemical reactions. • Nano-processing systems (Nano-mechanical processing) - Diamond turning: Soft metal single-point diamond turning technology, the ultra- precision CNC machine, plane and spherical mirrors machining; Nano- grinding: technology and requirements, concept of critical depth of cut, size-effect in form and fine grinding, Elid grinding, Elastic emission grinding; mechano-chemical polishing of Si wafers, principles and models; Ultra-precision polishing: Principles of ultra-precision polishing of block gauges, balls and aspherical lenses. Course Structure
- 4. 4 • Nano-processing systems (Nano-physical and –electrochemical processing): Photo beam processing: Thermal and chemical processes in photon beam ablation; Electron and ion beam processing: removal mechanism in electron and ion beam processing, abilities and limitations; scanning tunneling microscope (STM) processing; Chemically reactive milling and etching processes, Chemically reactive deposition and consolidation, electrochemical machining and deposition processes. • Nano-measuring systems: In-situ processes, mechanical and optical measuring systems, Scanning probe and image processing systems. • References • N. Taniguchi, Nanotechnology: Integrated Processing Systems for Ultra- precision and Ultra-fine Products, Oxford University Press Inc., NY, 1996. • J. McGeough, Micromachining of Engineering Materials, Marcel Dekker, Inc., NY, 2002. • M. C. Shaw, Principles of Abrasive Processing, Oxford: Clarendon Press, 1996. Course Structure
- 5. 5 Scheme of Assessment 1. Course Project: Micro-device Development - 30 % a) Literature Review and reporting b) Manufacturing feasibility study c) Manufacturing using the existing facilities 2. Quizzes - 20% 3. End semester Examination - 50% --------------------------------------------------------------------------- Total 100% ---------------------------------------------------------------------------
- 6. 6 Projects • Two students per team (or one in a rare case) • Overall Marks: 15% • Why projects? -Learning, thinking and applying “If you tell me, I will forget; if you show me, I may remember, if you involve me, I will understand” -Team work Learning to do a collaborative work
- 7. 7 Nature of Projects 1. Select a product which has certain applications 2. Use any process to fabricate it Precision Engineered Products BiomedicalAerospace EnergyPhotonics MEMS Electronics Applications
- 8. Facilities in Machine Tools Lab 8
- 9. 9 Hybrid Micro-machining Center Operations: § Micro Drilling § Micro Turning § Micro Grinding § Micro Milling § Wire EDM § Wire EDG
- 10. 10 High Speed Micro-machining Center Features: § Can be used for difficult to cut materials § High accuracy and precision § High rotational speeds § Micro milling § Micro drilling
- 11. 11 Electrical Discharge Machining (EDM) Setup Features: § CNC programmable § 3 axis machine § GM code § Rotating electrode
- 12. 12 Wire EDM Setup Features • Automatic wire treading system. • High speed EF (Electrolysis Free) discharge method. • High compatibility NC Program Design.
- 14. 14 KrF Excimer Laser Setup Features • Very high powers 0.2-1 J/pulse • Short pulses of 20 ns • Can be used for metals and polymers • Spot size of micro-meters
- 15. 15 Fiber Laser Setup Features • CW 100 W laser • Can also be pulsed to micro- seconds
- 16. 16 Nano-polishing set up Features • Can be used to reduce roughness to nanoscales
- 17. 17 White Light Interferometer (WLI) Features • Accurate surface topography • Sub-nanometer vertical resolution • 2D and 3D non-contact surface metrology
- 18. 18 Coordinate Measuring Machine (CMM) Features • A device for measuring geometrical features • Quality check and assurance • 3D CAD model generation from product
- 19. 19 Zeta 3D Optical Profiler Features § The Zeta system scans a sample over a user specified vertical (or Z) range. § At each Z position, it records the XY location and the precise Z height of the pixels using the Zeta Optics Module. § This information is used to create a true color 3D image and a 2D composite image
- 20. 20 Microscopes Tool Makers Microscope Alicona Microscope
- 21. 21 Some Examples Micro-grooves on bearings Grooves act as drawing and releasing paths for lubricants Can be produced using EDM 60-100µm deep micro-grooves Micro-delivery pin - Using wire EDM - used for capturing and delivering very small volume DNA liquid
- 22. 22 Some Examples Micro-pin hole matrix -Using EDM or micro-drilling - Used as a filter in optics applications 60-100µm deep micro-grooves Micro-electrode - Using micro-turning - used as electrode in EDM or ECM
- 23. 23 Some examples Micro Rods Micro rods EDM Tool 60 microns deep400 microns wide Micro Channels (Heat exchanger applications)
- 24. 24 Some Examples 3D MIDs (Molded Interconnect Devices) Step-1: Surface roughening of polymer Step-2: Followed by electroless plating or Laser direct sintering : Involves sintering powdered material on to the polymer surface using a laser
- 25. 25 What is expected? 1. Come up with a component that has application in the real world 2. Deduce strategies to fabricate the product 3. Choose the best one and do the fabrication Jan Feb Mar Apr Feedback Meeting Assessment (5%) Report, presentation Feedback Meeting Final Assessment (10%) Report & Presentation
- 26. Course Visit • A 2-day course visit to RRCAT, Indore • RRCAT hosts a number of advance technologies • Tentative Dates: March 5-7, 2020 26