C. E. Cross, University of Montana, Butte, MT
Amongst my more memorable research collaborations with Prof. Glen Edwards at the Colorado School of Mines was a study into the weldability of Ti-6211. It became apparent early in this study that there is a serious problem with formation of large columnar grains in the weld metal, a problem commonly experienced whenever titanium is welded. Titanium appears to be particularly insensitive to the competitive grain growth mechanism, which normally results in some grain refinement in other metals. The reason for this insensitivity is likely due to the limited amount of constitutional undercooling accruing from the limited partitioning of alloying elements. It may also be attributed to the flat shape of the weld pool. In this study, the phase equilibria of different alloying elements in titanium will be examined with regard to their effect on constitutional undercooling, and an approach for new filler alloy development will be proposed.
Summary: Amongst my more memorable research collaborations with Prof. Glen Edwards at the Colorado School of Mines was a study into the weldability of Ti-6211. It became apparent early in this study that there is a serious problem with formation of large columnar grains in the weld metal, a problem commonly experienced whenever titanium is welded. Titanium appears to be particularly insensitive to the competitive grain growth mechanism, which normally results in some grain refinement in other metals. The reason for this insensitivity is likely due to the limited amount of constitutional undercooling accruing from the limited partitioning of alloying elements. It may also be attributed to the flat shape of the weld pool. In this study, the phase equilibria of different alloying elements in titanium will be examined with regard to their effect on constitutional undercooling, and an approach for new filler alloy development will be proposed.
