Surface integrity characteristics of NiTi shape memory alloys resulting from dry and cryogenic machining

Abstract

NiTi alloys are extensively used in many industries due to their unique properties such as super elasticity, shape memory and phase transformation. Since the NiTi alloys have temperature-dependent mechanical and material properties, this work focuses on the effects of dry and cryogenic machining processes on surface integrity characteristics of NiTi alloys. Surface quality and topography, microstructure, transformation response and phase transformation temperatures of machined specimens are measured to assess the machining-induced surface integrity characteristics of NiTi alloys. Obtained results illustrate that machining of NiTi alloys under different cutting and cooling conditions affects their resulting surface integrity characteristics. Moreover, as compared to dry machining, cryogenic machining helps to improve surface quality and has substantial effects on the phase transformation behavior of machined specimens. (C) 2014 The Authors. Published by Elsevier B.V.