Paper Title
Stochastic Optimization of Surface Properties in WEDM of M42 HSS using Untreated and Cryogenated Treated Brass Wire

M42 super high speed steel is a finest cobalt high speed steel with a chemical composition intended for high hardness and better hot hardness. These properties make the steel an outstanding option for machining high-strength and prehardened steels, high-hardened alloys, and the difficult-to-machine, nonferrous super alloys used in the aerospace, oil, and power generation industries. Its applications are twist drills, milling cutters, taps, reamers, broaches, saws, knives, and thread rolling dies, but the inherent problem of machining these high speed steels with conventional machining processes necessitate the use of alternative machining processes. The wire electrical discharge machining(WEDM) processes has been found to be a good alternative of conventional machining processes, but there is lack of data and suitable models for predicting the performance of WEDM processes particularly for the M42 HSS. In the present work, the effect of shallow cryogenated brass wire on the M42 HSS is compared with the results of untreated wire on M42. The empirical modeling of process parameters of the WEDM has been carried out for the M42 HSS using a well known experimental design approach called response surface methodology(RSM). The parameters such as pulse-on, pulse-off, spark gap voltage and wire feed have been selected as input variables keeping others constant. The performance has been measured in terms of surface roughness. There is decrease in surface roughness value when we treat the M42 with cryogenated treated wire than the untreated wire. The optimized values before and after the cryogenated treatment achieved through mult i-response optimization are 1.79 μm and 1.39 μm. Keywords - Cryogenated, Optimization, Parametric, ANOVA, WEDM