Effect of Heat Treatment on the Microstructure and Tensile Properties of As-forged 2.5%(TiB+TiC)/Ti Composite

The effects of heat treatment on microstructure and mechanical properties of as-forged 2.5%(TiB+TiC)/Ti composite (volume fraction) have been studied. The results show that solution and aging treatments have a significant impact on the matrix characteristics and tensile properties of the composite. Equiaxed, bimodal and fully lamellar microstructures are obtained, the content of primary a declines while the content of the transformed beta phase increases with increasing of solution temperature. The TiB and TiC reinforcements are stable during heat treatment and their morphologies and distribution hardly change. The tensile strength increases while the elongation decreases after solution and aging treatment. With increasing of the solution temperature, both the tensile strength and elongation rise at room temperature, while the tensile strength and elongation tested at 650 degrees C exhibit a contrary tendency. After the heat treatment of 1050 degrees C/2 h/AC+600 degrees C/6 h/AC, the composite presents superior comprehensive properties including tensile strength of 1215.8 MPa and elongation of 3.14% at room temperature, while tensile strength of 629.9 MPa and elongation of 15.9% at 650 degrees C.