Corrosion behavior of calcium zirconate refractories in contact with titanium aluminide melts

This contribution investigated the corrosion mechanisms of calcium zirconate crucibles during vacuum induction melting of titanium aluminides. The crucibles withstood several melts and exhibited no cracking due to thermal shock. However, a significant amount of zirconium dissolved in the melt, whereas the oxygen content of the melt increased on a much lower level. In contrast to melting Ti6Al4V in the same crucibles an increased calcium zirconate content of the crucibles did not reduce the melt contamination of the titanium aluminide melts. The investigation of the corrosion front of the crucibles revealed the formation of calcium aluminates, whereas titanium was almost absent. The melting of titanium aluminides with subsequent refining by electro slag remelting could be a viable production route to produce titanium zirconium aluminum alloys. Furthermore, the relation between the corrosion of calcium zirconate refractories in contact with titanium based alloys depending on their composition should be further evaluated.