Model-supported optimisation of the sinter-HIP process

A sinter hot isostatic pressing (HIP) model is introduced for the material Al2O3 in which the final densification simultaneously includes defining the density development, grain growth and defect size reduction. The dependenc ies of these processes which influence each other are simulated in a comput er program and the model calculations are compared with the experimental re sults. For the selected combinations of processing and microstructural para meters, the individually dominating mechanisms and the achievable microstru ctural conditions can be thus identified. The results make conclusions poss ible about the size of the defects, which can be effectively reduced by the given processing and by optimised sintering kinetics. With a new type of d iagram (GDDT diagram), it is possible to simply represent the complex inter actions between the processing parameters and the microstructure developmen t. This allows the determination of optimal processing at given appropriate conditions, which thus allow the sintering and HIP processes to be optimal ly planned.