摘要
通过燃烧合成工艺制备了 Ti B2 - 4 0 % 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 Ti B2 是最稳定的相 ,中间相 Ti- Cu化合物最终转变为 Ti B2 相 ;XRD结果显示复合材料的相组成为 Ti B2 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 Ti B2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 Ti B2 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 Ti B2 - Cu基复合材料的致密度、弯曲强度和断裂韧性较 Ti B2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。
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
出处
《材料工程》
EI
CAS
CSCD
北大核心
2002年第9期14-17,共4页
Journal of Materials Engineering
基金
哈尔滨工业大学校科学基金资助 (项目号:HIT2 0 0 0 41)
中国博士后基金资助
