PIM - Influences on Surface Quality of PIM Parts

Powder Injection Moulding (PIM) is a net-shape production technology for complex metal or ceramic parts. It includes the process steps injection moulding for the production of green parts out of a feedstock, debinding for producing brown or white parts and sintering for producing final parts. Errors introduced during injection moulding cannot be compensated for in following process steps. Therefore it is important to investigate this process in order to learn more about the relation between injection moulding, tooling and the quality of the final part. For our investigation a test mould for a simple rectangular part is used. One of the mould plates can be changed for applying different surface quality in the cavity. The feedstocks consist of a water soluble binder and alumina powder with two grain sizes. The surface quality is characterised by the average surface finish Ra and the medium surface roughness Rz of green and sintered parts. Results of these investigations give important information for the design of feestocks, final parts and related moulds.