Numerical simulation and experimental analysis of solid-state sintering response of 316 L stainless steel micro-parts manufactured by metal injection molding

The metal injection molding process allows the manufacturing of small and very complex metallic components. Metal injection molding processing combines the shaping capability of polymer injection moulding with the large material variety of metals. This paper discusses in detail the development of a numerical model capable of simulating structural evolution and macroscopic deformation during sintering of complex micro-gear compacts. A sintering model based on elastic-viscoplastic constitutive equations was proposed, and the corresponding parameters such as sintering stress, bulk and shearing viscosities were identified from dilatometer experimental data. The constitutive model was then implemented into finite element software in order to perform the simulation of the sintering process. The numerical predictions of shrinkages and densities were compared with experimental measurements, and it is shown that the results numerically simulated by finite element agree well with those experimentally observed. The experimental data were obtained from sintering of stainless steel powders.