The effect of heat treatment on thermal stability of Ti matrix composite

The microstructures of in situ synthesized (TiB + La2O3)/Ti composite after β and TRIPLEX heat treatment are investigated. The room temperature tensile properties of the titanium matrix composites (TMCs) are tested, and thermal stability is carried out at 600, 650 and 700 °C for 100 h, respectively. The results show that the microstructure of specimen after β heat treatment is widmanstätten, while it is similar to basketweave after TRIPLEX heat treatment. Room tensile properties of specimen after TRIPLEX heat treatment are better than those of β heat treatment. After thermal exposure, the strength of specimens treated by β and TRIPLEX heat treatment increases, while the ductility decreases sharply, this is attributed to the precipitation of Ti3Al and silicides. The thermal stability of specimen after TRIPLEX heat treatment is better than that after β heat treatment.

Research highlights▶ The material is in situ synthesized (TiB + La2O3)/Ti composite. ▶ The TRIPLEX (β3) heat treatment is adopted. ▶ Tensile properties of specimen after β3 heat treatment are greater than those of β heat treatment. ▶ The thermal stability of specimen after β3 heat treatment is better than that after β heat treatment. ▶ The decrease of thermal stability is attributed to the precipitation of Ti3Al and silicides.