Ti2AlC/Al2O3复合材料的原位合成及其力学性能  

Synthesis and mechanical properties of Ti_2AlC/Al_2O_3 in situ composites

作　　者：刘建科[1] 解晨[2] 朱建锋[3] 叶兰[3] 

机构地区：[1]陕西科技大学理学院、教育部轻化工助剂化学与技术重点实验室,西安710021 [2]陕西科技大学电气与信息工程学院,西安710021 [3]陕西科技大学材料科学与工程学院,西安710021

出　　处：《功能材料》2015年第7期7143-7147,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51272145);陕西省自然科学专项基金资助项目(2011JM1014)

摘　　要：以Ti、TiC、Al和TiO2为原料,通过原位热压反应烧结法在1 350℃合成Ti2AlC/Al2O3复合材料。利用XRD详细研究了其反应过程,并分析了Al2O3对材料微观结构和性能的影响。结果表明,该体系在热压过程中的反应分多步进行,主要包括Ti粉与Al粉反应生成Ti-Al金属间化合物,TiO2与Al反应生成Al2O3以及Ti-Al金属间化合物与TiC反应生成Ti2AlC材料。原位反应生成的Al2O3均匀分布在Ti2AlC晶界上,抑制了Ti2A1C晶体的异常生长,从而使基体相Ti2AlC晶粒细小、均匀。力学性能测试表明Ti2AlC/12%(质量分数)Al2O3复合材料的硬度、抗压强度、抗弯强度和断裂韧性较Ti2AlC单相材料分别提高了66%,126%,130%和19.3%,并分析了其改性机理。Ti2AlC/12wt% Al2O3 composite was successfully synthesized from the powder mixture of Ti,TiC,Al and TiO2 by in situ hot-pressing method at 1 300 ℃.The reaction path and the effect of Al2O3 addition on the microstructure and mechanical properties of the Ti2AlC/12wt% Al2O3 composite were investigated in detail.It was found that the reactions of powder mixture during the hot press sintering contain several intermediate phases,including the formation of Ti-Al intermetallics from Ti and Al,reducing TiO2 by Al to form Al2O3,and reacting of TiAl intermetallics with TiC to form Ti2 AlC.Meanwhile,the in situ formed Al2O3 inhibits the abnormal growth of Ti2 AlC,and makes the microstrcture possess fine grains with a uniform dispersion.The Rockwell hardness,compressive,flexural strength and fracture toughness of the Ti2AlC/12wt% Al2O3 composite are increased by 66%,126%,130%,19.3%,compared to the monolithic Ti2 AlC.

关 键 词：TI2ALC AL2O3 微观结构 力学性能 

分 类 号：TQ174[化学工程—陶瓷工业]