Mechanical properties of partially sintered materials

In powder materials that are sintered only in the initial stage, a continuous network of pores remains in the structure. Here the mechanical properties of partially sintered materials are investigated in relation to processing parameters, sintering behavior, and microstructure, using, as a model material, W prepared by the activated sintering technique at low firing temperatures. Hardness and fracture toughness of partially sintered W are found to be critically dependent on the interparticle neck size of W sintered particles, which is in turn affected by the sintering additives. While fracture toughness is apparently solely a function of densification and interparticle neck size, hardness scales with a factor that combines both sintered density and densification. Existing analytical models for these scaling behaviors are compared critically with the new data.