Track: Manufacturing
Abstract
NiTi shape memory alloys are gaining wider importance due to their unique characteristics of super-elasticity, high strength, corrosion resistance, and shape recovery etc. that are very useful in various precision, scientific, and biomedical applications. They undergo extensive machining for production of parts to be used in the aforementioned applications. Conventional machining of shape memory alloys is challenging and new ways are being explored for enhanced machinability. In the present work, the Ni55.8Ti alloy has been machined by wire electric discharge cutting (WEDC) process and its machinability has been investigated. This paper mainly presents the analysis of the effect of WEDC parameters on recast layer thickness of the machined Ni55.8Ti alloy and optimization of process parameters for the minimum possible thickness of the recast layer. A total of 16 experiments have been conducted based on Taguchi L16 robust design of experiment technique with variation of four important WEDC parameters such as voltage, pulse-on time, pulse-off time, and wire feed rate at 4 levels each. ANOVA study has also been done, and pulse-on time has been found the most significant parameters affected recast layer thickness. The optimization of WEDC parameters resulted in very thin recast layer of <6 µm.