研究了Ni和Ti的添加对真空热压烧结方法制备的Al2O3-Ti(C,N)陶瓷基复合材料的显微组织和力学性能的影响.发现添加Ni和Ti的复合材料主要由Al2O3、Ti(C,N)和Ni组成,没有发现存在金属Ti.Ti由于非常活泼,在热压烧结过程中可能与石墨模具产生的含C气氛反应生成TiC,或与高温下Ti(C,N)的少量分解产生的N2气氛反应生成TiN,这有利于减少复合材料中的气孔.适量添加Ni可通过液相烧结促进复合材料的致密化,提高复合材料的相对密度,并能通过产生裂纹偏转和裂纹桥联提高复合材料的断裂韧性.热压温度为1550℃、等摩尔比的Ni和Ti混合粉末添加量为5vol％时,Al2O3-Ti(C,N)-Ni-Ti复合材料的相对密度为99.6％,硬度为21GPa,抗弯强度为818MPa,断裂韧性为8.1 MPa·m1/2.%Al2O3/Ti(C, N)-Ni-Ti composites were synthesized by vacuum hot press sintering. The effect of Ni and Ti on microstructure and mechanical properties were investigated. The results indicated that the composites with Ni and Ti addition were composed mainly of A12O3, Ti(C, N) and Ni with no Ti. Due to its high reactivity, Ti may react with the C containing atmosphere produced by the graphite die in the hot pressing process to form TiC, or with the possible N2 resulted from the small amount decomposition of Ti(C, N) at high temperature to form TiN, which is beneficial to the elimination of pores. Suitable addition of Ni promotes densification of the composites via liquid phase sintering, and increases relative density of the composites. Ni can also increase fracture toughness of the composites through crack deflection and crack bridging. With the addition of 5vol% of mixture of Ni and Ti (equal molar amount of Ni and Ti), the composite hot-pressed at 1500℃ has a relative density of 99.6%, Vicker's hardness of 21 Gpa, three point bending strength of 818 Mpa, and fracture toughness of 8.1 Mpa·m1/2.
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