不同界面SiC纤维束复合材料的拉伸力学行为

利用国产三代SiC纤维通过化学气相渗透工艺(CVI)制备不同界面厚度和基体体积分数的SiC纤维束复合材料,并对其拉伸力学行为进行研究;同时,通过有限元方法研究界面厚度和基体体积分数对SiC纤维束复合材料热残余应力的影响。有限元分析结果表明:该纤维束复合材料的界面存在较为明显的径向和环向热残余应力,而且这两种应力均随着界面厚度增加而减小,随着基体体积分数的增加而增加。拉伸实验结果表明:随着界面厚度增加SiC纤维束复合材料的拉伸强度有增大趋势,且纤维拔出长度也相应增加;但在界面厚度相同的情况下,过高的基体体积分数将导致复合材料拉伸强度和韧性下降。

Tensile mechanical behavior of SiC fiber bundle reinforced composites with different interfaces

Based on the domestic third generation SiC fiber,the SiC fiber bundle reinforced composites with different interface thicknesses and matrix volume fractions were fabricated by chemical vapor infiltration,and the tensile behavior of the composites was investigated.Meanwhile,the influence of interface thickness and matrix volume fraction on the thermal residual stress of the SiC fiber bundle reinforced composites was analyzed by FEM.The FEM results indicate that the radial and hoop thermal residual stresses are obvious at the interface;the two kind of stresses are decreased with the increasing of the interface thickness and are increased with the increasing of the matrix volume fraction.The tensile tests results show that with the increasing of interface thickness,the tensile strength of the SiC fiber bundle reinforced composites tends to increase,and the fiber pull-out length also is increased correspondingly;but under the same interface thickness condition,a high volume fraction of the matrix will lead to the degradation of the tensile strength and toughness of the composites.