An investigation of surface roughness and parametric optimization during wire electric discharge machining of cladded material

Abstract

The development of cladded materials to augment the industrial requirements is grown because of having combination of properties in end use applications. However, the real challenge regarding the application of these materials is its machining with reasonable surface finish and accuracy owing to the heterogeneous nature. Therefore, oftenly, thermal cutting process like gas cutting and plasma arc cutting are used, but these processes not only offer poor surface quality but also necessitate additional finishing operations. Wire electric discharge machining (WEDM) process is a viable alternate but the roughness generated on the two surfaces is different as the said process is thermoelectric in nature and both layers of material have different thermoelectric properties. In the current research the cutting performance of WEDM of stainless clad steel has been evaluated with a focus not only to reduce the surface roughness of individual layer but also to minimize the difference as well. The influence of uncommon parameters, such as layer thickness of specific layer, workpiece orientation, pressure ratio, and wire diameter are primarily investigated. Wire diameter and workpiece orientation have proved to be the significant control factors affecting the surface roughness of both the layers, whereas pressure ratio affects the surface roughness of one layer (mild steel). Optimal settings of control factors have been developed using grey relational analysis. The results of confirmatory experiment validates the model as not only the surface roughness of both layers have been decreased, but also the difference comes to be minimal of only about 0.02 μm.