UNIT 1 - INTRO - UCMP.pptx
- 2. CONTENTS History and Development. Conventional Machining Processes Limitations Of Conventional Processes Classification Of Unconventional Manufacturing Processes Unconventional Machining Processes Unconventional Forming Processes Classification of Unconventional machining processes Method of Machining Suitable for Different Materials Process selection parameters Advantages & limitations of Unconventional machining
- 3. Conventional machining process Metal is removed – Tool harder than work piece & subjected to Wear. Direct contact – Tool and work piece. Compression – shear chip formation.
- 4. Limitations of Conventional machining Metal is removed by chip formation which is expensive and difficult process. Chips produced during this process are unwanted by products. Removal of these chips and their disposal and recycling is a very tedious procedure, involving energy and money. Very large cutting forces. Greater amount of heat generated resulting in undesirable deformation and residual stresses. Delicate components cannot be produced – semi conductor.
- 5. Unconventional manufacturing processes Unconventional manufacturing processes can be divided into the following categories: Unconventional machining processes(UCMP) or Non- Traditional machining processes. Unconventional forming processes.
- 6. Unconventional manufacturing processes Unconventional machining processes(UCMP) or Non- Traditional machining processes. No traditional tool for metal removal. Utilises some form of energy for metal machining. No direct physical contact between the tool and work piece. Tool material need not to be harder than work piece material.
- 7. Unconventional manufacturing processes Unconventional forming processes In this metals are formed through the release and application of large amounts of energy in a very short time interval.
- 8. Need for unconventional machining Technological advanced industries requirement for HSTR (High strength temperature resistant material). Material to high strength to weight ratio. Productivity is not be hampered because of high strength, hardness, toughness and other diverse property materials. Economic cutting speed. Production of complex shaped products. Better surface finish and tolerances, high production rates.
- 9. Classification of UCMP Medium of transfer of energies. High voltage particles Electrolyte Electron Hot gases Source of energy required for material removal Hydrostatic pressure High current density High voltage Ionised material Based on mechanism involved in the process Erosion Ionic dissolution vaporisation Based on type of energy required to shape the material Thermal Electrical Electro chemical Chemical Mechanical
- 10. Classification of UCMP – Energy Methods Thermal Energy Methods. Laser Beam, plasma arc, Electron Beam, Ion Beam Electrical Energy Methods. Electro discharge Machining, wire cut electrical discharge machining Electro chemical Energy Methods. Electro chemical machining, Electro chemical grinding, electro chemical honing, electrical chemical deburring. Chemical Energy Methods. Chemical machining. Mechanical Energy Methods. Ultrasonic machining, abrasive jet machining, water jet machining.
- 11. Method of Machining Suitable for Different Materials Sl.N o Material Method of Machining 1 Non – Metals like ceramics, plastics, glass USM, AJM, EBM, LBM 2 Refractories USM, AJM, EDM, EBM 3 Titanium EDM 4 Super alloys AJM, ECM, EDM, PAM 5 Steel ECM, CHM, EDM, PAM
- 12. Process selection The following point must be considered for the selection of the unconventional machining processes: Physical parameters Shapes to be machined Process capability or machining characteristics Economic consideration.
- 13. Process selection - Physical Parameters
- 14. Process selection – Shapes to be machined
- 15. Process selection – Process capability The machining characteristics can be analyzed with respect to : Metal removal rate obtained Tolerance maintained Surface finish obtained Depth of surface damage Power required for
- 16. Process selection – Process economy The economics of various processes are analyzed by considering the following points: Capital cost Tooling cost Power requirement Metal removal rate efficiency
- 17. Advantages and limitations Advantages It increases productivity It reduces no. of rejected components Close tolerance is possible Tool need not to be harder than work piece Harder material can be machined. The machined surface do not have any residual stresses. Limitations Expensive Metal removal rate is low AJM, CHM, PAM, EBM are not commercially economical processes.