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采用箔-纤维-箔法和1150℃/150 MPa/30 min的真空热压工艺成功制备了SiCf/Ti-43Al-9V复合材料,并使用金相显微镜、X射线衍射仪、扫描电镜及能谱仪对该复合材料微观组织的形成进行了研究。结果表明,制备过程中SiC纤维与TiAl基体合金发生反应,并形成一定厚度的反应层;基体组织为等轴晶,粒径约为8μm,与原始合金组织相比明显细化;从反应层到远处的TiAl基体合金,基体合金的组织由全γ相转变为α2/γ片层组织、γ晶粒和晶间B2相的混合组织。其中全γ相区域的厚度为2~4μm,并围绕纤维分布。根据Ti-Al-V相图、C原子和V原子的扩散,分析了这两个基体区域的形成机理,并结合热压成形过程中的塑性变形和变形储存能,解释了基体合金晶粒大小的变化。
The SiCf / Ti-43Al-9V composites were successfully prepared by foil-fiber-foil method and vacuum hot pressing at 1150 ℃ / 150 MPa / 30 min. The microstructure of the composites was characterized by means of metallographic microscope, XRD, SEM and EDS The formation of the composite microstructure was investigated. The results show that SiC fiber reacts with TiAl matrix alloy during the preparation process and forms a certain thickness of reaction layer. The matrix structure is equiaxed and has a grain size of about 8μm, which is obviously refined compared with the original alloy. From the reaction layer to In the distant TiAl matrix alloy, the microstructure of the matrix alloy changes from the all-γ phase to the α2 / γ lamellar structure and the mixed structure of γ grains and intergranular B2 phase. The thickness of the whole γ-phase region is 2 ~ 4μm, and distributed around the fiber. According to the phase diagrams of Ti-Al-V, the diffusion of C atoms and V atoms, the formation mechanism of these two matrix regions was analyzed. Based on the plastic deformation and deformation energy storage in the hot press forming process, the grain size of the matrix alloy The change.