Mechanical properties and microstructure of TiB2/ZrB2/SiC composite functional materials composites

TiB2/ZrB2/SiC functional composite materials were fabricated by the spark plasma sintering technology. Phase composition and microstructure of the composite were analyzed by XRD and SEM. The bend strength, fracture toughness and hardness were detected. The results show that the particle size of TiB2/ZrB2/SiC powder is 2~4 μm after double milling refinement, which makes the size and distribution uniform, and almost without reunion phenomenon. Moreover, the new phases of (TixZry) B2 solid solution are produced in the sintered functional composite. When the volume fraction of ZrB2 is 30%, the generated (TixZry) B2 solid solution plays a very important role in grain refinement and interface fusion. The bending strength and fracture toughness of TZS30 composite ceramic materials are much higher than TZS0, which are increased by 119.8% and 98.9%, respectively. Meanwhile, the self-lubricating of TiB2/ZrB2/SiC ceramic materials can be realized by the friction chemical reaction with oxygen under high-temperature.