Metallographic changes and phase identification in a nickel base alloy upon fusion and casting

Three groups of tensile test pieces were produced using a nickel base partial denture castin alloy and employing induction fusion in each case. The first group was produced from new metal, the second from metal which had been recast four times, and the third from new overheated metal. Samples of alloy were cut from each group and, together with a piece from an original ingot, were mounted, polished, etched, and examined under a metallurgical microscope in order to determine the nature and extent of the metallographic changes resulting from fusion and casting of the alloy.