This task focused on liquid phase sintering and infiltration studies of refractory metals and metal composites. Particular emphases was placed on those powered metal compacts which produce liquid alloys in sintering. For this class of materials, heating to a two phase region causes the constituent components to react, forming an alloy liquid which must wet the solid phase. Densification is initially driven by the free energy effects which cause rapid rearrangement. Further densification occurs by evaporation and condensation, surface diffusion, bulk flow, and volume diffusion