Manufacturing of a gear wheel made from reaction bonded alumina - numerical simulation of the sinterforming process

Sinter forming is a recently developed process for the production of advanced ceramic components. It combines pressure-supported sintering and superplastic deformation, and allows RBAO (Reaction Bonded Alumina) to be sintered without grain coarsening due to the reduction of process time and dwell temperature. Thus, sinterforming can achieve near net shaping and defect free components for highly stressed applications. As many phenomena interact during sinter forming, the process parameters for producing complex shaped parts are difficult to identify without numerical tools. Therefore, a micromechanical model for solid state sintering has been used to investigate the process. The model was extended to consider source controlled diffusion in order to describe the non-linear stress/strain dependence. Several experiments were made in order to determine the material parameters of the model. The model has been implemented as a user subroutine in ABAQUS/Explicit® and is validated by numerical simulations of the accomplished experiments. To show the possibilities of the finite element simulation, the sinter forming process is numerically carried out for a RBAO gear wheel.