三维正交Cf/Al复合材料的显微组织与弯曲性能

采用真空压力浸渗法制备了Cf体积分数为50%的三维正交Cf/Al复合材料,主要研究了复合材料的显微组织以及室温、高温下的弯曲性能,并分析了复合材料弯曲失效机理。结果表明,三维正交Cf/Al复合材料经向显微组织的微孔缺陷较纬向显微组织要略多,复合材料在室温、350℃和400℃时,弯曲强度分别为498.8、363.0、303.0 MPa,弯曲模量分别为70.8、63.7、65.6GPa。其中,弯曲失效主要由于内侧面受压应力导致经向纤维束屈曲变形,纬向纤维束形态较完好;外侧面受拉应力导致复合材料拉伸破坏,存在纤维拔出现象。

Microstructure and Bending Properties of Three-dimensional Orthogonal Cf/Al Composites

Three-dimensional orthogonal Cf/Al composites with volume fraction of 50%Cfwere fabricated by vacuum pressure infiltration.The microstructure and bending properties of the composites at room temperature and high temperature were investigated.The failure mechanism of bending properties of the composites was described.The results indicate that the micro-void defects in the warp microstructure of three dimensional orthogonal Cf/Al composites are slightly more than those in the weft microstructure.The bending strength of the composites at room temperature、350℃and 400℃reaches 498.8 MPa、363.0 MPa and 303.0 MPa,respectively.The bending modulus of the composites at room temperature、350℃and 400℃reaches 70.8 GPa、63.7 GPa and 65.6 GPa,respectively.The bending failure is mainly attributed to the buckling deformation of the warp fiber bundles caused by the compression on the inner surface,and the morphology of weft fiber bundles is relatively intact.In addition,the tensile failure of the composites is caused by the tension of the external side and existence of fiber pull-out.