1 / 20

I. Menzies, P. Koshy McMaster University, Canada

Assessment of Abrasion-Assisted Material Removal in Wire EDM. I. Menzies, P. Koshy McMaster University, Canada. 58 th CIRP General Assembly, Manchester August 25, 2008. 1970. generator technology coated wires high pressure flushing adaptive control. workpiece height & taper

noelle-bell
Download Presentation

I. Menzies, P. Koshy McMaster University, Canada

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Assessment of Abrasion-Assisted Material Removal in Wire EDM I. Menzies, P. Koshy McMaster University, Canada 58th CIRP General Assembly, ManchesterAugust 25, 2008

  2. 1970 • generator technology • coated wires • high pressure flushing • adaptive control • workpiece height & taper • surface finish • machining accuracy & precision Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  3. Kruth et al (2004) • Machining speed & surface integrity continue to be issues of focus in current wire EDM research rough trim surface integrity Aspinwall et al (2008) ~40X cutting rate Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  4. The issues of machining speed and surface integrity are interlinked Aspinwall et al (2003) Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  5. Enhancing the ejection efficiency is the key to simultaneously improving the removal rate and the surface integrity • Need for innovation Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  6. Hybrid machining entails the integration of processes with distinct mechanisms of material removal to exploit their synergy El-Hofy (2005) Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  7. Grinding + EDM • Thermal softening of workpiece • In-process dressing & declogging Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  8. Extension of the concept to wire EDM rod wire Masuzawa et al (1985) discharge area • Different from Wire Electro Discharge Grinding Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  9. wire • Material removal by melting/vaporization and two-body abrasion ph > gw reference voltagedielectric strength Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  10. Fixed abrasive diamond wire used in the electronics industry • Issues with wire guide and electrical power feed Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  11. wire failure by embrittlement • experiments using wire with no abrasives for comparison of removal rate & recast layer, and estimation of gap-width Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  12. Wire characterization 50 m 180 micron core 50 micron (nominal) diamond Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  13. Force measurement by considering force equilibrium in reference to wire bow and wire tension Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  14. Order of magnitude enhancement in the removal rate wire sawing • Steepest gradient in the increase in removal rate is in line with the maximum force gradient edm Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  15. 108 V, 8 A • Increase in the removal rate is due to abrasion 20 m 162 V, 8 A Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  16. wire-EDM • Machined surface 108 V, 8 A • Wire performance degrades rapidly with repeated use abrasion-assisted used wire Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  17. Comparison of recast material steel nickel wire-EDM abrasion-assisted Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  18. Wire feed strategies Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  19. Conclusions & Outlook • Proof-of-concept of an innovative abrasion-assisted wire EDM process has been presented • The process has the potential to significantly enhance the removal rate and the quality of the machined surface, particularly for metal matrix composites that are difficult to wire EDM • The process is perhaps best implemented on a twin-wire machine tool • Research effort is required to formulate wires with aluminum oxide abrasives, with a core that has good sparking and grain retention characteristics • Electrical discharges could possibly enhance wire sawing of brittle materials through controlled thermal shock-induced fracture Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

  20. Thank you for your attention! Natural Sciences & Engineering Research Council of Canada Assessment of abrasion-assisted material removal in wire EDM I. Menzies, P. Koshy 58th CIRP General Assembly Manchester, August 25, 2008

More Related