Application of the Grey-Taguchi Method for the Optimization of Lost Wax Mold

Abstract

Investment casting technology is negligible in Ethiopia on account of the cost of investment casting is considerably higher than the sand casting due to the cost of the importation of the wax and refractory materials. In this work an attempt has been made to develop an alternative local mold material which is capable of providing hard, high strength, thermal stable shell for lost wax casting technology to manufacture intricate part. It optimizes the lost wax mold compositions based on Taguchi method and Grey relational analysis in order to obtain the particular refractory composition with optimum multiple characteristics of the mold. From Grey relational analysis response it is found optimum result that the local investment slurry with the refractory type of fired clay, its quantity of 35%, marl clay of 4%, water content of 23%, wheat husk of 35%, cow dung of 2%, mold drying time of 24 hours and the firing temperature of 8000C. The confirmation experiments showed that the results of mold compositions were optimized for achieving the combined objectives of higher compression strength of material, lower linear and volumetric expansion value on the dried mold.