Investigating the surface roughness of implant prepared by combining fused deposition modeling and investment casting

Abstract

Fused deposition modeling is widely used for printing three-dimensional models of biomedical implants as functional/ nonfunctional prototypes. In the present work, experimental investigations have been made for controlling surface roughness of implant (hip joint) prepared by combining fused deposition modeling and investment casting as a case study. The process started with printing of implant (hip joint patterns) using acrylonitrile butadiene styrene (ABS) as filament material with fused deposition modeling and, thereafter, functional prototype has been developed through investment casting route using SS316L. Three controllable factors of the investment casting process (namely, number of slurry layers, slurry viscosity, and dry time of primary layer) were studied at three levels each by Taguchi’s parametric approach and single-response optimization was conducted to identify the main factors controlling surface roughness ( Ra) of cast specimens. The results of the study suggest that for Ra, percentage contribution of number of layer, viscosity of primary dip, and dry time of primary coating is 41%, 32%, and 25%, respectively.