Simulation of sintering of nanoparticulate micropreforms in a microfabrication process Original Research Article

Microcasting is a technique for fabricating ceramic and metallic microstructures and involves sintering of a nanoparticulate green body as the final step to produce the microparts. The sintering kinetics at the nanoparticulate scale determines the local sintering stress throughout the micropreform, which, in turn, affects the overall shape deformation of the final sintered products. This paper presents a numerical analysis on the coupled sintering processes using a viscous sintering mechanism to illustrate the methodology for multiscale simulations. A microscopic model for viscous sintering is adopted to describe the micro/nanostructural evolution by considering the effects of nanoparticle mechanics on the sintering kinetics. The overall dimensional change of the sintered micropart is determined based on the local sintering stress in the green body, which is evaluated using the evolution of the micro/nanostructure during sintering. The multiscale model is used to explore the effects of the various material and process parameters on the shape evolutions during sintering and on the final sintered shape of microparts.