纤维增韧陶瓷基复合材料的比例极限应力与残余热应力关系

Relationships between proportion limit stress and residual thermal stress for CFRCMC

从细观力学角度分析并建立了纤维增韧陶瓷基复合材料从制备温度冷却到室温过程中产生的残余热应力与复合材料的比例极限应力的关系模型。该模型表明,减少复合材料的残余热应力或提高复合材料的纤维与基体的模量比,均可提高复合材料的比例极限应力。通过单调拉伸实验测试了先驱体浸渍裂解法(PIP)制备的2D SiC/SiC复合材料的比例极限应力,并采用文中建立的比例极限应力与残余热应力关系模型,计算出复合材料SiC基体的残余热应力为-19.5 MPa。分析表明,该结果是合理的。此外,引用了公开文献报道的5种复合材料体系数据,用于验证文中所建立的比例极限应力与残余热应力关系模型的适应性和可靠性,计算结果与实验结果最大误差为18.6%,表明该模型具有较好的适应性和可靠性,可为纤维增韧陶瓷基复合材料的研究提供新思路。

The relational model between the proportion limit stress （PLS） of continuous fiber reinforced ceramic matrix composites （CFRCMC） and the residual thermal stress （RTS） due to cooling down from the fabricating temperature to room temperature by the mesomechanics view.The PLS and RTS relational model shows that either decreasing the RTS in the CFRCMC or improving modulus ratio of fiber to matrix could enhance the PLS of the CFRCMC.The PLS of 2D SiC/SiC composites fabricated by Polymer Impregnation Pyrolysis （PIP） process was obtained by the unidirectional tensile test,and the RTS in SiC matrix with a reasonable value of-19.5 MPa was calculated by the relational model.In addition,the paper referred to five kinds of CFRCMC systems data reported in published literatures to verify the adaptability and reliability of the paper established PLS and RTS relation model.The results show that the maximum deviation between the calculated results the experimental ones is 18.6%,which means that the PLS and RTS relational model has good adaptability and reliability,and then,it may provide a novel train of thought for the CFRCMC research.