Mechanical structuring, surface treatment and tribological characterization of steel mould inserts for micro powder injection moulding

Manufacturing of ceramic and metallic micro components in micro powder injection moulding (μPIM) requires mould inserts offering high wear resistance and a sufficient demoulding behaviour. Within the frame of this research μPIM mould inserts made from low and high alloyed tool steel were structured by micro milling and finished by micro peening and ultrasonic wet peening. Influence of surface condition on wear and demoulding behaviour of the steels in μPIM with ceramic feedstock was characterized using a laboratory tribotester simulating powder injection moulding and a specially adapted static friction tester. Results indicate that performance of mould inserts in micro powder injection moulding depends not only on hardness, surface condition and homogeneity of the mould insert materials but also is strongly influenced by the characteristics of the feedstock, like composition of the binder or amount and hardness of the ceramic particles.