Y-12 development organization technical progress report: Part 3 - metal processing, period ending September 1, 1994

The authors melted and cast an aluminum-uranium (Al-U) alloy by vacuum induction melting (VIM) prealloyed buttons made by arc melting. The resulting alloy casting displayed a large compositional gradient from top to bottom. The authors sampled the resulting casting for uranium to check homogeneity. The sampling revealed that the top of the casting contained 23.5 wt% uranium, and the bottom (an average of two samples) contained 42.4 wt% uranium. Although each button contained 36.5% uranium, these analyses show that the solidified casting was inhomogeneous. If the buttons were homogeneous, the segregation occurred during induction melting, and this method may not be feasible for making AL-U alloys. If the buttons were not homogeneous, perhaps arc melting the buttons more times would have helped. Bottom pouring the Al-U melt into a mold for faster cooling could also help prevent segregation