Compression process effects on filling density and replication properties of micro-surfaces during metal injection molding

摘要

To improve the surface replication properties and density of final metal injection molded (MIM) products, injection-compression molding was applied to metal-mold processing. Effects of the mold temperature and compression process conditions, such as the compression period, on the density, surface roughness, and geometry of green compacts and sintered products were investigated. The density of green compacts, cavity pressure inside the mold, and surface roughness were improved for longer compression periods of both pressure and volume control methods. Micro-scale replication properties for the V-grooves of green compacts revealed a complicated tendency involving the compression period and control method. The V-groove replication properties improved with increasing compression period, except for the volume control method and lower mold temperature. The sintered MIM products' final properties strongly affect the characteristics of green compacts. The injection-compression process for MIM products, e.g. metal-polymer complexes, can improve the surface replication properties and roughness of green compacts.