ENHANCED SINTERING THROUGH 2ND PHASE ADDITIONS

The available data confirm the criteria for enhanced sintering which are outlined. These critieria include solubility, segregation, and diffusivity concepts which can be related to binary phase diagrams. Successful additives have a high solubility for the base material, form relatively low melting temperature phases, and exhibit a decreasing liquidus and solidus with alloying. Beyond these criteria, the various factors contributing to favorable mechanical behavior are listed. Several materials have been subjected to enhanced sinering treatments; examples have been taken from studies on iron, molybdenum, and tungsten. Optimization of mechanical properties dictates further phase equilibria and processing requirements. Thermodynamic and kinetic factors are discussed. Phase diagrams provide an excellent starting point for selecting candidate systems.