Gravitational Effects on Compact Shaping and Microstructure during Supersolidus Liquid Phase Sintering of Cu-10Sn-10Pb

With increasing sintering temperature, liquid is pulled down by gravity and it causes porosity elimination at this area. The difference in liquid volume fraction makes microstructural gradient from up to bottom of sintered compacts. In this paper the influence of gravity on shape and also microstructure evolution of compacts was studied. Cu-10Sn-10Pb samples were sintered at the range of 890-970°C for 20 min. The in situ images from samples were taken at various sintering conditions. It is concluded that distortion increases from top to bottom sections of samples due to viscosity reduction and the weight of upper sections. Liquid volume fraction at the bottom increases with increasing sintering temperature and finally elephant foot profile is appeared. Lead plays an important role in fragmentation and rearrangement of bronze particles and this affects on shape and microstructure during sintering.