Temperature sensitivity in the chemically activated sintering of hafnium

The addition of small quantities of transition metals to the surface of refractory-metal powders results in enhanced low-temperature densification during sintering. The effect is well documented for tungsten. In the d-electron exchange model, the activated sintering process is considered to be a consequence of the differing electron distributions in the refractory and activator metals. As part of a general investigation of the d-electron exchange model, the experiments described in this paper were performed to determine if, as predicted by the model, the sintering of hafnium is activated by the addition of selected transition metals. (Auth.)