Phase transformations in reactive sintering of tungsten

It has been demonstrated recently that tungsten (T-m=3410 +/- 20 degrees C) can be sintered by reactive sintering in a reductive atmosphere such as hydrogen. This alternative technique to the conventional sintering (T-s > 2000 degrees C) makes use of a small amount of aluminium addition which acts as a sintering aid and hence lowers the sintering temperature significantly (T-s <= 1200 degrees C). This study explores the phase transformations that take place during reactive sintering of tungsten in view of the mechanisms involved. DSC, SEM and TEM have been used for a fundamental understanding of this system.