Surface integrity evolution from main cut to finish trim cut in W-EDM of shape memory alloy

J. F. Liu, L. Li, Y. B. Guo

Research output: Contribution to journalConference articlepeer-review

25 Scopus citations


Shape memory alloys such as Nitinol are widely used in medical, aerospace, actuator, and machine tool industries. However, Nitinol is a very difficult-to-machine material due to the superelasticity, high ductility, and severe strain-hardening. This study explores the process capability of W-EDM (DI-water based dielectric) in machining Nitinol Ni50.8Ti 49.2 by one main cut (MC) followed by four trim cuts (TC). Experimental results show that the 6-sigma distributions of Ra are very different between MC and finish TC. Thick white layers (2-8 μm) with microcracks in MC and very thin white layers (0-2 μm) free of those defects in finish TC can be observed. However, microcracks would not propagate into the heat affected zone (HAZ) below the white layer. The white layer by TC is about 50% higher than that by MC. In addition, Ni is the dominant element for the measured microhardness.

Original languageEnglish (US)
Pages (from-to)137-142
Number of pages6
JournalProcedia CIRP
StatePublished - 2014
Externally publishedYes
Event2nd CIRP Conference on Surface Integrity, CSI 2014 - Nottingham, United Kingdom
Duration: May 28 2014May 30 2014

All Science Journal Classification (ASJC) codes

  • Control and Systems Engineering
  • Industrial and Manufacturing Engineering


  • Shape memory alloy
  • Surface integrity
  • W-EDM


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