“In the field of materials science, researchers have prepared small-sized TiAl alloy samples with high Nb content using vacuum non consumable tungsten arc melting technology, and studied the microstructure and hardness changes of the alloy under rapid solidification and different annealing conditions using ANSYS software. The results indicate that the microstructure at the bottom of the rapidly solidified alloy is uniformly refined, and there are strip-shaped B2 phases in the residual α phase. The α →α 2+γ is suppressed, and solidification segregation exists in both the middle and top of the alloy. At an annealing temperature of 850 ℃, as the annealing time increases, the microstructure at the bottom of the sample becomes more uniform and fine, with blocky γ - phase (γ m) and a small amount of B2 phase present. The solidification segregation in the middle region is improved, while the segregation at the top is more severe; After annealing at 850 ℃× 0.5h and 850 ℃× 1h, the B2 phase in the middle and top of the sample showed discontinuous point like distribution, while after 850 ℃× 3h heat treatment, the B2 phase was mainly distributed in a vein like pattern. The microhardness of rapidly solidified alloys by rapid cooling is relatively high, and with the extension of annealing time, the overall average hardness shows an upward trend, but there are differences in the distribution of microhardness in different regions.”