论文部分内容阅读
以Ti-Al-Ti_3AlC_2为反应体系,采用真空热压技术(1100℃×1 h)制备Ti_2AlC/TiAl基复合材料。借助XRD、SEM等测试手段分析相组成以及微观结构,并测量其密度、维氏硬度、抗弯强度、抗压强度和断裂韧性等室温力学性能。结果表明,产物主要由TiAl、Ti_2AlC和Ti_3Al相组成。利用Ti_3AlC_2分解反应原位自生的Ti_2AlC增强相主要分布于基体晶界处,部分钉扎于晶内,且随着Ti_2AlC生成量的增大,团聚现象加剧。室温力学性能测试表明,Ti_2AlC/TiAl基复合材料的力学性能明显优于单相TiAl材料,当Ti_3AlC_2掺杂量为10 mass%时,综合性能较好,密度、硬度、抗弯强度、抗压强度和断裂韧性分别为3.97 g/cm~3、4.82 GPa、488.61 MPa、1340 MPa和5.68 MPa·m~(1/2)。断裂机制主要表现为沿晶断裂、穿晶断裂、裂纹偏转与桥联;颗粒相增韧、裂纹偏转与桥联以及层状增韧是主要的增韧方式。
Ti 2 AlC / TiAl matrix composites were prepared by vacuum hot pressing (1100 ℃ × 1 h) using Ti-Al-Ti_3AlC_2 as reaction system. The phase composition and microstructure were analyzed by means of XRD and SEM, and the mechanical properties at room temperature such as density, Vickers hardness, flexural strength, compressive strength and fracture toughness were measured. The results show that the product mainly consists of TiAl, Ti 2 AlC and Ti 3 Al phases. In situ Ti3AlC_2 decomposition reaction using Ti 2 AlC reinforcement phase mainly distributed in the matrix grain boundaries, some pinned in the crystal, and with the increase of Ti 2 AlC formation, agglomeration increased. The mechanical properties at room temperature show that the mechanical properties of Ti_2AlC / TiAl matrix composites are obviously better than that of single phase TiAl. When the content of Ti_3AlC_2 is 10%, the comprehensive properties are better. The density, hardness, flexural strength, compressive strength And fracture toughness were 3.97 g / cm ~ 3,4.82 GPa, 488.61 MPa, 1340 MPa and 5.68 MPa · m ~ (1/2), respectively. The fracture mechanism mainly includes intergranular fracture, transgranular fracture, crack deflection and bridging; the toughening mode is the toughening mode of particle phase toughening, crack deflection and bridging and layered toughening.