Microstructure and mechanical properties variation of TiB/Ti matrix composite by thermo-mechanical processing in beta phase field.

TiB reinforced titanium matrix composite with a near alpha alloy matrix was fabricated using in situ technologies. The Widmanstatten microstructure evolution of the composite and the TiB whiskers realignment effect during thermo-mechanical processing were investigated, and the mechanical properties of the composite were measured. It was found that the microstructure of the composite is refined significantly by the thermo-mechanical processing due to the recrystallization of beta grains. With the increase in deformation amplitude, the value of probability density of small orientation angles of TiB whiskers along extension direction increases sharply. Strength of the composite was increased significantly by the thermo-mechanical processing, which results from the increase in the strengthening effect of TiB whisker and the microstructure refinement. The value of the thickness of alpha plates (b) without precipitated sillicide has minor effect on the strength of the composite but it becomes a non-ignorable strengthening factor after sillicide precipitation due to its dislocation hindering effect. [ABSTRACT FROM AUTHOR]