Effect of process parameters on surface roughness of hybrid investment casting

Abstract

Fused deposition modelling (FDM) is one of the additive manufacturing technologies that can be effectively used for making patterns for investment casting. This method is considered to be economical for low volume of production as tooling is not involved in this process. However, the surface finish of the patterns produced by using FDM machine is poor as compared to wax patterns produced by using a die. The surface finish of the castings produced by the investment casting process are dependent on the surface finish of the pattern, therefore in order to use plastic patterns instead of wax patterns, there is a need to improve the surface finish of the FDM patterns. For this purpose, a coating of thin layer of wax has been proposed on the plastic patterns made by using FDM. In this paper the effect of wax coating and other process parameters has been studied on the surface roughness of the castings.