An experimental study of influence of wire electro discharge machining parameters on surface integrity of TiNiCo shape memory alloy

Abstract

Shape memory alloys (SMAs) are unique class of smart materials with excellent physical, mechanical and biomedical properties, which have wide applications in several fields such as aerospace, robotics, biomedical, and dental etc. These alloys are well known for exhibiting shape memory effect (SME) and pseudoelasticity (PE), it is a well-established fact that they are required to be processed into functioning parts. The conventional machining affects the internal properties of shape memory alloys and hence, it is reported that nonconventional machining techniques are more suitable. Wire electro discharge machining (WEDM) is one of the nonconventional machining processes for machining complicated shapes without hampering the internal properties of such type of materials. In the present experimental investigation, wire electro discharge machining of Ti 50 Ni 40 Co 10 shape memory alloy (SMA) has been carried out and machining performances such as surface roughness (SR), and material removal rate (MRR) have been evaluated. Experimental results exposed that pulse on time, pulse off time and servo voltages are most influential process parameters on the responses. The machined surface has been characterised with respect to microstructure, microhardness, and phases formed.

Surface Analysis of Wire-Electrical-Discharge-Machining-Processed Shape-Memory Alloys

“…In another study, Chaudhari et al [10] concluded that T on , T off , and current are the main influencing factors for the response variables of the material-removal rate(MRR), surface roughness (SR), and microhardness for the WEDMof nickel-based alloys. Soni et al [23] explored the WEDM of Ti50Ni40Co10 SMA with the output variables of MRR and SR. Increasing values of MRR and SR were reported with increasing T on , while both values decreased with increasing T off and servo voltage. Researchers used brass and copper wires as electrodes, and studied their effect on the surface integrity of amachinedSMA surface [19,20].…”

Effect of cobalt addition on the corrosion behavior of near equiatomic NiTi shape memory alloy in normal saline solution: electrochemical and XPS studies

“…Alloys containing up to 10% of cobalt were also studied for material removal rate, microstructure and hardness with wire electro discharge machining technique. 29 In order for these alloys to be successfully used, the effect of cobalt on the corrosion resistance properties must be well dened. Huang et al 26 investigated the corrosion properties of these alloys in PBS solution, claiming similar behavior to cobaltless NiTi alloys and no effect of galvanic corrosion within stent.…”

Wire electro spark machining and characterization studies on Ti50Ni49Co1, Ti50Ni45Co5 and Ti50Ni40Co10 alloys

“…In this research wire spark discharge machining process is adopted to perform machining study on TiNiCo smart materials by varying the elemental compassions. In WEDM process machining, performances are based on input process parameters such as pulse duration, servo voltage, wire speed and wire diameter are highly influencing parameters [10]. Removal of material from the work is based on spark erosion and vaporization which are highly controlled due to servo voltage and pulse durations [11].…”