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采用自蔓延燃烧合成及真空电弧熔炼的方法,以碳纤维(Cf)、钛粉及铝粉为原料,合成了Ti2AlC/TiAl复合材料。通过X射线衍射(XRD)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析了复合材料的物相组成和微观结构,讨论了原位合成Ti2AlC的反应和二次Ti2AlC的析出过程。结果表明,复合材料铸锭由Ti2AlC、TiAl和Ti3Al3相组成,基体由α2(Ti3Al)+γ(TiAl)片层和γ(TiAl)等轴晶粒构成,原位自生的Ti2AlC分布均匀,呈短纤维状或颗粒状。1200℃均匀化热处理促使Ti3Al分解为TiAl和Ti2AlC,导致Ti2AlC粗化,同时基体表面析出细小的二次Ti2AlC颗粒。
Using self-propagating combustion synthesis and vacuum arc melting method, carbon fiber (Cf), titanium powder and aluminum powder as raw materials, Ti2AlC / TiAl composite material was synthesized. The phase composition and microstructure of the composites were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The reaction of in situ synthesis of Ti2AlC and the precipitation of secondary Ti2AlC were discussed. The results show that the composite ingot consists of Ti2AlC, TiAl and Ti3Al3 phases. The matrix consists of α2 (Ti3Al) + γ (TiAl) lamella and γ (TiAl) equiaxed grains. The in-situ Ti2AlC distribution is uniform and short Fibrous or granular. The homogenization heat treatment at 1200 ℃ promoted the decomposition of Ti3Al into TiAl and Ti2AlC, resulting in the coarsening of Ti2AlC and the fine secondary Ti2AlC particles precipitated on the surface of the matrix.