Investigation of wire electric discharge machining of stainless-clad steel for optimization of cutting speed

The use of cladded materials has grown up in manufacturing industry as it provides a blend of properties in end-use applications. However, the cutting of a cladded material is really considered as a challenging task owing to their heterogeneous nature; therefore, it is often subjected to thermal cutting processes like gas cutting or plasma arc cutting. But thermal cutting processes offer poor surface finish and require subsequent finishing operations. Wire electric discharge machining (WEDM) is a competent alternate in terms of surface finish, but this process offers relatively low cutting rates. In this research work, an attempt has been made to evaluate and optimize the cutting performance of WEDM for cutting stainless-clad steel in terms of cutting speed which is one of the most crucial considerations in manufacturing. In addition to the commonly studied WEDM parametric effects, the influence of workpiece orientation, layer thickness of individual layer, wire diameter, and pressure ratio of dielectric fluid on the cutting speed is mainly evaluated. Taguchi’s L18 orthogonal array has been used for experimental design. Optimal combinations of machining parameters to maximize the cutting speed are extracted through various statistical analyses, and it has been found that the proposed optimal set of parameters results into an improvement of about 20% in cutting speed in WEDM of stainless-clad steel. It has also been observed that the individual layer thickness of the cladded material plays a vital role in controlling the cutting speed of WEDM. The contribution of stainless steel layer thickness on cutting speed is found to be two times as compared to the contribution of mild steel layer.