Effects on Microstructure and Material Properties for TiNiCo Shape Memory Alloy

Wire spark discharge machining of TiNiCo alloys for bone staple applications is presented. Vacuum arc melting furnace was used to developed TiNiCo alloys with varied cobalt content (1, 5 and 10 at. %). The investigation has been performed to study the material removal rate (MRR) and surface quality (Ra) as per the experimental design planned for L33 array. Input process parameters are Pulse on/off duration servo voltage, wire speed and servo feed. From the responses on MRR and Ra optimal process conditions were identified using multi-objective grey analysis. It is understood that the results obtained for different combinations of materials are insignificant due to the property of the element weight percentage. The surface of bone staple (Non-implanted) is characterized with respect to surface morphology, surface topography, recast layer thickness, microhardness and residual stresses. The smoother machined surface and compressive residual stresses have been noticed which are favourable in improving the fatigue life of machined bone staples.