Investigating the effect of vacuum pressure, refractory grain size and vibrations on the quality characteristics of casting produced through vacuum moulding

Abstract

Vacuum moulding (VM) is one of the green manufacturing processes, which is still struggling for establishing its commercial applications. The main drawbacks of VM process are its poor surface finish, lack of dimensional accuracy, internal defects like porosity, infeasibility to produce complex geometric counters, etc. Apart from this, VM process is cost effective, versatile, environmental friendly and produces minimum waste; hence it can be modified to meet up the today’s manufacturing standards. In this present research work, an experimental exercise has been made for the optimization of some of the well-known casting characteristics such as micro-hardness (Mh) and porosity (P) by employing design of experimental (DoE) technique. In this three input process variables, namely vacuum pressure (VP), refractory grit size (Rgs) and frequency of vibration (Fv) were considered (each of three levels) and optimized with Taguchi L9 orthogonal arrays. It has been found that Vp and Rgs were found as most effective parameters for Mh and P, respectively, of the resulting castings.