Sintering behavior and post-sintering microstructure depend to a large degree on the processing conditions. This paper discusses presintering condition effects on subsequent liquid phase sintering densification and distortion during both ground-based and microgravity sintering. The materials system used is tungsten heavy alloy. The study provides unique insight into the events accompanying densification and shape distortion such as solid-liquid segregation and pore stability. Solid-liquid segregation is closely connected to densification. Presintering conditions play an important role in the mobility and the location of the pores in the sample. In ground-based sintering, the cold isostatically pressed sample has the most uniform solid-liquid distribution with the largest shrinkage. In microgravity sintering, the vacuum presintered sample shows the largest degree of densification and elimination of pores.
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