Impact of binder constituents on the moldability of titanium-based feedstocks used in low-pressure powder injection molding

Abstract

This work presents an experimental and numerical approach to study the impact of binder constituents and solid loading on spherical titanium powder-based feedstocks used in low-pressure powder injection molding. The viscosity profiles of 35 feedstocks were used to quantify the threshold proportions of each constituent. The binder which maximizes the moldability and demolding while minimizing the segregation is constituted of 1, 1 and 3 vol% of stearic acid, ethylene-vinyl acetate and carnauba wax, respectively, and paraffin wax making up the balance. The maximum solid loading capable of producing intricate parts with minimal defects was found to be 64 vol%. Finally, numerical simulations were carried out along with experimental validation to study the injection flow in an intricate mold cavity. Results show that numerical simulations are in good agreement with experimental values in predicting the melt front position during injection of high solid loading feedstock in complex shape cavity.