采用真空热压烧结技术制备了纳米TiC体积分数为3%~5%的Al2O3/TiC/Mo/Ni微纳陶瓷复合材料, 并对其力学性能、相对密度、微观结构和三点弯曲断口形貌进行了研究。结果表明: 微纳陶瓷复合材料中存在非典型的灰芯/白环结构; 复合材料的断裂方式为穿晶断裂和沿晶断裂的混合形式; 添加的纳米粒子分布于Al2O3基体晶粒的内部与晶界, 形成了晶内/晶界型结构, 细化了晶粒, 强化了晶界, 提高了复合材料的强度和相对密度, 其抗弯强度、断裂韧度、硬度和相对密度分别为970 MPa, 5.5 MPa·m1/2, 20.4 GPa和99.5%。

Al2O3/TiC/Mo/Ni micro-nano-ceramic composite with 3 vol.%-5 vol.% of nano-sized TiC particles was fabricated by hot-pressed sintering in vacuum. The mechanical properties, relative density, microstructure and three-point-bending fracture surface morphology of the composite were studied. Results show that there was a non-typical structure of gray core/white rim in the microstructure of the composite. The composite fractured as a mixing mode of intergranular fracture and transgranular fracture. As the added nano-sized TiC particles dispersed in the boundaries or inside of the grains of the Al2O3 matrix, intragranular and intergranular structures formed, grains were refined, and the grain boundaries were strengthened, thus the strength and relative density of the composite improved. The bending strength, fracture toughness, Vichers hardness and relative density were 970 MPa, 5.5 MPa·m1/2, 20.5 GPa and 99.5%, respectively.