Improvement of Titanium Alloy Ingot Consolidation

摘要

An attempt was made to develop a manufacturing method for the elimination of nitride inclusions from titanium alloys as they are melted. The trial scheme involved skull casting as the first of two melting stages. Ten-inch-diameter ingots of Ti-6Al-4V were produced with artificial nitride defects added. The ingots were converted to one-inch-thick plates for evaluation. Preliminary results of examining rolled plates revealed that the proposed manufacturing method failed to eliminate the synthetic nitride-induced flaws. Also, the degree to which it may have helped is uncertain because of the appearance of extraneous types of defects and difficulties in finding and identifying defects. Metallographic specimens were prepared from all major defect areas. The defects were differentiated according to microstructure and their composition was determined by microprobe analyses. (Author)