Effect of process parameters on surface hardness, dimensional accuracy and surface roughness of investment cast components

This paper deals with investment casting (IC) application for development of spherical disc of ball valve as a case study. Three controllable factors of the IC process, namely: volume/surface-area (V/A) ratio of components, slurry layer';s combination (LC) and type of metal (MT), were studied at three levels by Taguchi's parametric approach and single-response optimization was conducted to identify the main factors controlling surface hardness (SH), surface roughness (Ra) and dimensional accuracy (=d). Ceramic shell moulds were made on wax plate using primary slurry and fused-silica sand as stucco. Castings were produced using Al, M.S and S.S at recommended arameters by following Taguchi L9 orthogonal array through ceramic shell IC process. The microstructure analysis has been used to study the surface morphology.