Effects of casting conditions on the primary structure of Ti-48Al-2Cr-2Nb alloy

Studies were conducted to establish the influence of casting conditions (casting temperature and temperature mould) on the primary structure and the quality of ingots melted in vacuum induction furnaces and the cast to be mould made of different materials. The examinations presented in the paper showed the significant role in forming the primary structure of Ti-48Al-2Cr-2Nb plays the material of mould and thermal gradient on the boundary liquid-casting mould. Besides the equiaxed zone, there is a distinct columnar zone in the primary structure of ingots with the gradient increases. It was found most beneficial is casting to the cold graphite moulds, overheat this alloy to the 1773 K temperature. We can obtain ingots (casting) with structure consisted of fine grain equiaxed only and shallow shrinkage cavity and metallic yield over than 70%. (author)