Mechanical behavior and microstructure evolution of Ti-6.5Al-2Zr-1Mo-1V/TiB metal-matrix composites during deformation

Abstract. The Ti-6.5Al-2Zr-1Mo-1V/TiB metal-matrix composites with different amounts of TiB reinforcements (~2.0, 6.0 and 10.0 vol. %) were produced by vacuum arc melting. The initial microstructure of the synthesized composites composed of two-phase α+β matrix with embedded boride particles. The addition of borides resulted in 15-35% increase in strength without a visible drop in ductility. The alloy with the highest amount of the reinforcement attained yield strength of 1100 MPa, peak strength of 1670 MPa and compression ductility of 10 % at room temperature. Microstructure evolution during hot compression was associated with dynamic recrystallization of the matrix and rearrangement/shortening of TiB fibers. The composite with 10.0 vol. % of TiB demonstrated noticeably higher strength at elevated temperatures in comparison with non-reinforced alloy.