Effect of gating system on porosity and surface roughness of femoral stem in centrifugal casting

Abstract

The objective of this research is to investigate porosity and surface roughness in the femoral stem. Commercially pure titanium (CP-Ti), vertical centrifugal casting method and investment mould were used to produce the femoral stem which has three gating system designs. The “A” gating system design has three ingates, the “B” design has four ingates and the “C” design has four ingates with different position of the femoral stem from the “A and B” designs. The least porosity is the gating system designs which it supplies molten metal to the largest modulus section during solidification. The surface roughness is affected by external shrinkage of the femoral stem. A longer solidification time increases the external shrinkage and the surface roughness. The “A” gating system design in this research has better quality than the others because it has the least porosity and uniform of the surface roughness.