A Study on Optimum Machinability of NiTi Shape Memory Alloy Via AWJ.

The high ductility behaviour and high hardening of Nickel–Titanium (NiTi) alloys during cutting make them one of the alloys with low machinability. In addition, poor chip breakage and high tool wear are observed when machining these materials with conventional manufacturing methods. One of the unconventional processing methods, abrasive water jet (AWJ), is an alternative method for cutting low machinability materials. In this study, NiTi shape memory alloy (SMA) was subjected to AWJ drilling under different machining parameters. The aim of the research is to determine the optimum kerf (K), surface roughness (Ra) and material removal rate (MRR) variables resulting from the drilling process by examining the effect of process variables such as water pressure (WP), stand-off distance (SoD) and feed rate used in AWJ machining of NiTi SMAs. Taguchi-based Gray Relational Analysis (GRA), one of the multi-criteria decision-making methods, was used to optimise machining parameters in the drilling of NiTi SMAs with AWJ. The effect percentages of the test levels in the drilling operations were determined using Analysis of Variance (ANOVA). As a result of the experimental study, optimum levels were obtained for K, MRR and Ra at low WP, medium SoD and high feed rate. According to the result obtained from ANOVA, the parameter with the highest effect on K, MRR and Ra was determined as feed rate with 34.65%. [ABSTRACT FROM AUTHOR]