Significant improvement in cutting rate during WEDM of clad-composite using zinc-coated wire

Abstract

ABSTRACTThe accurate cutting of clad-composites through conventional practices is difficult due to the intrinsic heterogeneity of the constituent layers. Thermal cutting (gas/plasma) is commonly employed for machining of such composites. But thermal cutting yields poor cut quality, deep heat-affected regions and needs subsequent finishing operations. Wire electric discharge machining (WEDM) is a valuable substitute but the issue of low cutting rate limits its use. Therefore, this research aims to address the low cutting rate issue to justify the feasibility of WEDM for cutting of stainless-steel clad-composite. In addition to considering the workpiece and process-associated factors, zinc-coated wire is used in WEDM of cladded-workpiece. Experimental results obtained under L18 designed experiments are comprehensively analyzed through various statistical and optical microscopic analyses. Empirical model and optimal parametric combination have also been achieved and validated via confirmatory experiments. An improvement of 50.5% in cutting rate is realized with coated wire at S/N-optimal settings as compared to cutting rate achieved at L18-optimal settings using uncoated brass wire in WEDM of clad-composite. This improvement in cutting rate is attributed to the zinc-coating that pronounces the discharge capability of wire owing to its higher electrical conductivity.