Constitutive modelling of microstructured components fabricated by micro powder injection molding

A constitutive model based on Besson and Abouaf's constitutive equation was established to simulate densification of 316L stainless steel microstructured components fabricated by micro powder injection molding. A new sintering stress expression for final stage sintering was established by including the variation in grain number during grain growth. Different diffusional creep, sintering stress and internal gas pressure were assumed for the substructure, in the millimeter regime, and the microsize structures, respectively. The predictive capability of the model was verified by comparing the theoretical calculations with the experimental results. The calculations agreed reasonably well with the experimental results. Neglecting the variation in grain number in the sintering stress was found to yield lower predicted densities of the microsize structures.