Nature of dissolution of binary tantalum-titanium alloys by molten plutonium

Tantalum hardware has often been used for the processing of molten Pu where ceramics are inappropriate. However, there has only been limited work on the containment of Pu by Ta alloys. In this regard, the authors have investigated the interaction of Ta-Ti alloys (20, 40 and 60 wt.% Ti) with molten Pu at 850 and 1,000 C. The microstructures of Pu/alloy interfaces were characterized chemically and metallographically following various exposures to liquid Pu. Dissolution does not proceed uniformly, but appears to initiate by intergranular attack to a shallow depth and then progress by the formation of a stable mushy zone at the liquid/solid interface. The resistance to dissolution by molten Pu increases with the Ta content of the alloy