Influence of (TiC+TiB) on the microstructure and tensile properties of Ti-B20 matrix alloy

• After forging, the microstructure was significantly refined and uniform.
• The presence of carbide and boride also led to uniform and finer precipitation of α during aging as compared to the matrix alloy.
• The size of secondary α phase increased with the increase of aging temperature. This trend leads to the decrease of strength and the increase of ductility.

A hybrid of (TiB+TiC) reinforced beta titanium matrix (Ti-B20) were produced by non-consumable arc-melting technology and hot-forging. Microstructures of the composites were observed by optical microscopy (OM), transmission electron microscope (TEM) and scanning electron microscopy (SEM). The results show that both the TiB whiskers and TiC particles tend to segregate at β boundaries. The β grain size and secondary α lath width are refined by reinforcements and aging treatment. Evolution of tensile properties shows that enhancement in yield strength and ultimate tensile strength with the addition of reinforcements, as well as the remarkable increase in the ductility can be attributed to aging treatment at 600 °C and 650 °C. The size of secondary α phase increased with the increase of aging temperature. This trend leads to the decrease of strength and the increase of ductility to get good balance of properties. The fracture mechanism of the composite can be attributed to the cracking of the reinforcements.