MICROSTRUCTURAL REFINEMENT OF W-NI-FE HEAVY ALLOYS BY ALLOYING ADDITIONS

The success of grain refinement and strengthening of the tungsten heavy alloy by the addition of body-centered cubic refractory metals leads to the concept of idealized phase diagrams. The ideal additive should be totally soluble in tungsten and show high solubility in the matrix alloy. The idealied phase diagrams are shown. Accordingly, other additions like vanadium, niobium, and chromium should improve the sintered strengths. The strengthening effect comes from both the solid solution alloying and microstructure control aspects associated with these additions.