原位自生Ti3 Al金属间化合物基复合材料的微观结构

摘要

采用原位自生(XD)法制备Ti3Al金属间化合物基复合材料．对复合材料的XRD、OM和sEM的分析结果表明：Ti-17Al-0.5C复合材料的基体为Ti3Al、增强相为Ti3AlC，且增强相在基体中按一定的方位排列；Ti-17Al-1.5(2.0)C复合材料的基体为Ti3Al、增强相由心部TiC和包覆层Ti3AlC双层组成，随着含C量的增加，增强相由不发达的树枝晶变为等轴晶．对合金进行显微力学探针测试表明，增强相TiC和Ti3AlC的显微硬度和弹性模量均大于基体Ti3Al．随着C含量的增加，合金中增强相和基体的显微硬度和弹性模量无明显变化．%Ti3Al intermetallic matrix composites were prepared using a XD (exothermol deposition) method.The experimental results of composites obtained by XRD, OM, SEM techniques, and electron probe microa-nalysis indicate that in Ti-17Al-0.5C composite the matrix and the reinforcement are Ti3Al and Ti3AlCphases respectively, and the reinforcement has an orientation relationship with the matrix. However, in Ti -17Al-1.5 (2.0) C composites the matrix is Ti3A1, and the reinforcement is TiC coated with a Ti3AlC layer.With increasing C content, morphology of reinforcement changes from undeveloped dendrite to equiaxial den-drite. The microhardness and the elastic modulus of reinforcement and matrix were tested by MPM. The meas-ured results show that the microhardness and the elastic modulus of TiC and Ti3AlC are higher than that of thematrix Ti3Al. The microhardness and the elastic modulus of reinforcement and matrix have little variation withincreasing C content.