Al_2O_3–ZrO_2/Co–Ni–BN金属陶瓷的制备与性能

Preparation and Properties of Al_2O_3–ZrO_2/Co–Ni–BN Cermets

用真空热压烧结工艺制备了Al_2O_3–ZrO_2(3Y)/Co–Ni–BN金属陶瓷。用扫描电子显微镜及能谱分析了样品显微组织及断裂形态,研究了金属相Ni–Co和陶瓷增强相h-BN的含量对样品力学性能的影响以及抗热震性能。结果表明:在烧结温度为1 500℃、压力为30 MPa、保温30 min条件下,当Ni–Co–BN含量为12%(质量分数)时,样品的最佳抗弯强度、断裂韧性、Vickers硬度分别为1 423 MPa、14.7 MPa·m^(1/2)、13.4 GPa。样品的临界热震温差为500℃,其热震断裂因子和损伤因子分别为R′=12 981.8 J·(m^2·s)和R″″=145μm;断裂功为557 J/m^2。

Al2OH-ZrO2（3Y）/Co--Ni-BN cermet was prepared by a vacuum hot pressing sintering method. The microstructure and fracture mode of metal ceramic was measured via scanning electron microscopy and energy dispersive spectroscopy. Moreover, effects of Ni--Co metallic phase and h-BN reinforced ceramic phase contents on the mechanical properties were investigated. In addition, the thermal shock resistance of Al2O3-ZrO2（3Y）/Co-Ni-BN was also analyzed. The results show that when the content of Ni-Co-BN is 12% （in mass fraction） the optimum bending strength, fracture toughness and hardness of metal ceramic prepared at 1 500 ℃ and 30 MPa for 30 min are 1 423 MPa, 14.7 MPa.m1/2 and 13.4 GPa, respectively. The threshold temperature difference of thermal shock is 500 ℃. The thermal shock fracture factor （R′, damage factor （R″″and rupture power are 12 981.8 J/（m2·s）, 145 μm and 557 J/m2, respectively.