Dynamic recrystallization and silicide precipitation behavior of titanium matrix composites under different strains

Abstract

In order to elucidate the microstructure evolution and silicide precipitation behavior during high-temperature deformation, TiB reinforced titanium matrix composites were subjected to isothermal hot compression at 950 °C, strain rate of 0.05 s−1 and employing different strains of 0.04, 0.40, 0.70 and 1.00. The results show that with the increase of strain, a decrease in the content, dynamic recrystallization of the α phase and the vertical distribution of TiB along the compression axis lead to stress stability. Meantime, continuous dynamic recrystallization reduces the orientation difference of the primary α phase, which weakens the texture strength of the matrix. The recrystallization mechanisms are strain-induced grain boundary migration and particle stimulated nucleation by TiB. The silicide of Ti6Si3 is mainly distributed at the interface of TiB and α phase. The precipitation of silicide is affected by element diffusion, and TiB whisker accelerates the precipitation behavior of silicide by hindering the movement of dislocations and providing nucleation particles.