Effects of particle distribution on microstructural evolution and mechanical properties of TiB2/AZ31 composite sheets

In-situ TiB2/AZ31 composites were prepared by self-propagating high-temperature synthesis reaction assisted with the coupled-field dispersion treatment. The samples of as-cast AZ31 alloy and in-situ TiB2/AZ31 composites with and without the coupled-field dispersion treatment were thermal deformed by cross-rolling. The influence of TiB2 particle distribution on the microstructures and mechanical properties of the composites was investigated. It was found that the as-cast microstructure of AZ31 matrix was refined by TiB2 particles. The uniform dispersion of the TiB2 particles is favor of further refinement. All as-rolled samples were composed of recrystallized small grain streams and relatively coarse grains. The improvement of reinforcement dispersion made the grain streams thinner and increased their amount, but had little influence on the texture evolution. The strength and elongation of TiB2/AZ31 composites increased simultaneously due to the promotion of particle distribution induced by coupled-field dispersion treatment.