Hybrid effect of TiCp and TiBw co-strengthening Ti matrix composites prepared by spark plasma sintering and hot extrusion

Abstract

Ti matrix composites singly and hybrid-strengthened by TiCp and TiBw were prepared and their mechanical properties were studied by tensile tests at room temperature. Then, hybrid strengthening effect of TiCp and TiBw was studied by contrastive experimental studies and theoretical calculations. Results showed the high strength of (TiCp + TiBw)/Ti composites came from the collective reaction of different strengthening factors and that their contributions were TiB whiskers > hybrid effect > grain refinement of matrix > O/N solution > TiC particles in general. Hybrid effect closely depended on the ratio of TiCp to TiBw. With the increase of TiCp/TiBw mole ratio from 1:4 to 4:1, the hybrid effect decreased continuously. This study provided quantitative and quasi-quantitative descriptions on different strengthening factors, and could benefit the chemical and microstructural design of Ti matrix composites with good combination of high strength and favor ductility.