TiB2-Cu基复合材料的燃烧合成研究

通过燃烧合成工艺制备了TiB2-40%Cu(质量分数）基复合材料，对复合材料的反应热力学、相组成以及微观组织进行了研究。热力学计算结果表明TiB是最稳定的相，中间相Ti-Cu化合物最终转变为TiB2相；XRD结果显示复合材料的相组成为TiB2相和Cu相，没有生成其他中间相；微观组织观察表明，合成产物组织致密，增强体TiB2陶瓷颗粒尺寸细小，形貌主要呈近等轴状和块状，Cu作为金属粘结剂将TiB2陶瓷颗粒相互连接在一起，Cu的存在促进了燃烧合成过程中材料的致密化行为。Cu的加入使TiB2-Cu基复合材料的致密度、弯曲强度和断裂韧性较TiB2纯陶瓷均有大幅度提高，材料的韧化机制为裂纹尖端塑性钝化机制。

Study of TiB2-Cu Composite by Combustion Synthesis

The quasi static consolidation in uniaxial compression of combustion synthesized TiB 2 40%Cu(mass fraction) composite from Ti, B and Cu powders was investigated Microstructure and properties of the composite was also studied by XRD,XEM,and EPMA Thermodynamics of the system was calculated theoretically The results show that the TiB 2 is stable phase in the composite Interphase TiCu can convert into stable phase Only TiB 2 and Cu phases, without other phases, exist in the synthesized product It is consistent with the calculated result of thermodynamics The microstructure is dense Fine TiB 2 reinforcement grows in near equivalent axis like and block like shapes Copper as binder phase exists between TiB 2 and TiB 2 particles It is shown that copper improves the densification behavior during combustion synthesis The relative density, bend strength and fracture toughness of TiB 2 Cu composite is much higher than those of TiB 2 ceramic Crack tip plastic blunting by a ductile metallic phase and crack deflection by the stress due to the difference of thermal expansion coefficient and elastic modulus between TiB 2 and Cu are the principal mechanisms of toughness improvement of the composite