POWDER INJECTION MOLDING OF NANOSCALE SILICON NITRIDE

摘要

Silicon nitride (Si_3N_4) exhibits many functional properties that are relevant to applications in electronics, aerospace, defense and automotive industries. However, the successful translation of these properties into final applications lies in the net-shaping of ceramics into fully dense microstructures. Increasing the packing density of the starting powders is one effective route to achieve high sintered density and dimensional precision. The present paper presents an in-depth study on the effects of nanoparticle addition on the powder injection molding process (PIM) of Si_3N_4 powder-polymer mixture. Mixing, injection molding, debinding and sintering was successfully demonstrated for a wax-polymer feedstock containing nanoscale Si_3N_4 powders. In addition, feedstock properties were measured and successfully used in Moldflow simulations of an aerospace engine part. The above results provide new design perspectives for PIM of silicon nitride that could impact a wide range of applications.