Segregation of molybdenum atoms to the liquid-solid interfaces in liquid phase sintering of W-8 pot Mo-7 pct Ni-3 pct Fe

Partitioning of elements during sintering of W-8 pet Mo-7 pet Ni-3 pet Fe a lloy was investigated with respect to various isothermal holding times, ran ging from 5 to 240 minutes, at a sintering temperature of 1500 degreesC, It was found that the precipitation of W and Mo atoms from the liquid phase o nto the W-Mo grains was competitive in nature, with W atoms showing a great er tendency to precipitate. Due to this fact, Mo atoms gradually segregated to the interface between W-Mo grains and the liquid phase. The accumulatio n of Mo atoms near the interfaces thus changed the interfacial properties a nd, consequently, reduced the rate of interfacial reaction (solution and pr ecipitation), which was responsible for the transition of the controlling m echanism of grain growth from diffusion of W atoms in the liquid phase to t he interfacial reaction.