Effects of TiB on the variant selection and spheroidization of secondary α phases at different cooling rates in TiB-TC25G composites

The evolution of the texture and microstructure of TiB-TC25G composites, heat-treated in the high ?+? phase field, have been studied with different cooling rates. The present study found that the size of ? colonies and the thickness of individual secondary ? laths increased with decreasing cooling rates. Slow cooling induces the formation of equiaxed secondary ? grains in the ? matrix of TiB-TC25G composites. Attributed to the TiB, the intensity of ? texture in TiB-TC25G composites decreased with decreasing cooling rate, which is inconsistent with the results of variant selection during the ??? phase transformation in traditional titanium alloys. The misorientation analysis suggested that some of the equiaxed secondary ? grains do not follow the Burgers orientation relationship (BOR) with the parent ? grain. In this study, the role of TiB in influencing variant selection and the morphology of the secondary ? phase with different cooling rates were analyzed.

Automated summary

The evolution of the texture and microstructure of TiB-TC25G composites heat-treated in the high ?+? phase field was studied with different cooling rates. The study found that the size of ? colonies and the thickness of individual secondary ? laths increased with decreasing cooling rates, leading to the formation of equiaxed secondary ? grains. The intensity of ? texture in TiB-TC25G composites decreased with decreasing cooling rate due to the presence of TiB, and some equiaxed secondary ? grains did not follow the Burgers orientation relationship (BOR) with the parent ? grain.