Investigating the Effect of Shape Factor, Slurry Layers and Pouring Temperature in Precision Investment Casting

Abstract

This paper aimed to investigate the effect of shape factor, slurry layers and pouring temperature in precision investment casting. Three controllable factors of the precision investment casting process (namely: shape factor, slurry layers (mold thickness) and pouring temperature) were studied at three levels each by Taguchis parametric approach and single-response optimization was conducted to identify the main factors controlling surface hardness, dimensional accuracy (Δd) and surface roughness (Ra). Castings were produced using aluminum (Al), mild steel (M.S.) and stainless steel (S.S) at recommended parameters through ceramic shell precision investment casting process. The micro structure analysis has been used to study the surface morphology. Analysis shows that for surface hardness, contribution of shape factor, slurry layers and pouring temperature is 0.07%, 0.70% and 99% respectively. As regards to surface roughness, contribution of shape factor, slurry layers and pouring temperature is 1.14%, 16.80% and 81.90% respectively. Further for Δd contribution of shape factor, slurry layers and pouring temperature is 1.53%, 22.47% and 72.88% respectively. Confirmation experiments were conducted at an optimal condition showed that the surface hardness, Δd and Ra of the precision investment casting were improved significantly.