Weak interface dominated high temperature fracture strength of carbon fiber reinforced mullite matrix composites
Weak interface dominated high temperature fracture strength of carbon fiber reinforced mullite matrix composites
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DOI：
10.1016/j.jeurceramsoc.2017.03.033
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发表时间：
2017-07
影响因子：
5.7
通讯作者：
L. Yang;H. T. Liu;R. Jiang;X. Sun;W. Mao;H. F. Cheng;J. Molina-Aldareguia
中科院分区：
文献类型：
--
作者：
L. Yang;H. T. Liu;R. Jiang;X. Sun;W. Mao;H. F. Cheng;J. Molina-Aldareguia
陶瓷基复合材料的增韧性能主要取决于纤维/基体之间的弱界面。本文报道了一种新型的溶胶-凝胶法制备的碳纤维增强莫来石基复合材料，其中纤维/基体界面的剪切性能是固有的弱（1.25 MPa），通过纤维推入试验测量原位。透射电子显微镜观察表明，界面微观结构具有明显的化学特征。弱界面的结果是裂纹偏转等增韧机制的充分触发，用单边缺口梁法测得复合材料的断裂韧性为12 MPa·m ~（-1）。最后，由于纤维/基体界面较弱以及纤维和基体的大的热膨胀失配，高温断裂强度在25 ° C至1200 °C的温度范围内增强，这归因于在升高的温度下界面性质的增强，这有利于复合材料组分之间更好的载荷传递。
Weak fiber/matrix interface dominates the toughening properties of ceramic matrix composites. This paper reports a novel sol-gel fabricated carbon fiber reinforced mullite matrix composite, in which the fiber/matrix interface was inherently weak in shear properties (∼25 MPa), measuredin-situby fiber push-in tests. The interface microstructure was chemically sharp, characterized by transmission electron microscopy. The outcome of the weak interface was the full trigger of the toughening mechanisms like crack deflection,etc., leading to significant enhancement of the fracture toughness of the composite (∼12 MPa√m), measured by single edged notch beam method. Finally, due to the weak fiber/matrix interface and large thermal expansion mismatch of the fiber and matrix, the high temperature fracture strength was enhanced in the temperature range from 25 to 1200 °C, which is attributed to the enhancement of the interfacial property at elevated temperatures that favors better load transfers between composite constituents.