Variant selection and texture studies in Ti-6246

Detailed texture studies were carried out on originally weakly and strongly textured Ti-6246. Samples of the two as-received conditions were β-heat treated, followed by controlled cooling (0.1°C/s) and subsequent rapid quenching from temperatures between 700 and 850°C. Since Ti-6246 does retain any present β-phase when quenched, it is possible to freeze the high temperature microstructure at any stage of the cooling process. A number of interesting observations were made during this study. Firstly, even though the applied cooling rate was fairly slow, no α nucleation was observed until 850°C. When quenched from 800°C, mainly grain boundary α was observed with columnar α lamellae starting to grow from grain boundary α. It was also found that the strong β-texture found in the textured material was completely randomized during the relatively short β heat treatment. Detailed texture studies using EBSD confirmed that grain boundary α plays an important role in the selection of the variant even in material, which has a macroscopically random texture. On the other hand, variant selection is also seen in the as-received strongly textured material, which had been cooled at a fast rate and therefore showed little growth of α from grain boundary α.