Effect of β heat treatment temperature on microstructure and mechanical properties of in situ titanium matrix composites

摘要

TiB and La_2O_3 reinforced titanium matrix composites were in situ prepared by casting and hot working. An effort was made to investigate relationship between β heat treatment temperature, microstructure and mechanical properties. Tensile tests were performed at room temperature, 600, 650 and 700 ℃, respectively. Results indicated that composites treated at 10 ℃ above β transus points obtained fine grain microstructures and superior mechanical properties. When composites were treated at 20 ℃ above β transus points, the larger α colonies sizes led extremely decreased strength and the effect of reinforcements' volume fraction on matrix of composites was reduced; dominant failure modes at high temperatures also differed from the fine microstructure.