Effect of Heat Treatment on the Microstructure and Properties of As Forged 2.5vol.% (TiB TiC)/Ti Composite

Abstract:

The effects of heat treatment on microstructure and mechanical properties of as forged 2.5vol.%(TiB TiC)/Ti composite have been studied in this paper. The results showed 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 were obtained, the content of primary α reduces while the content of the transformed β phase increases with increasing of solution temperature. The TiB and TiC reinforcements are stable during heat treatment and their morphologies and distribution have no obvious change. The tensile strength increases while the elongation decreases after solution and aging treatment. With increasing of solution temperatures, both the tensile strength and elongation rises at room temperature, while the tensile strength and elongation tested at 650 oC exhibit a contrary tendency. The composite presents superior comprehensive properties with tensile strength of 1215.8MPa and elongation of 3.14% at room temperature, while tensile strength of 629.9MPa and elongation of 15.9% at 650 oC after the heat treatment of 1100 oC/2h/AC 600 oC/6h/AC.

Key words:Titanium matrix composite, Heat treatment, Microstructure, Mechanical property