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为分析 Si C W层状复合材料增韧机理 ,对以 Si C陶瓷胶片为基体层 ,金属 W为夹层的 Si C W层状复合材料进行了力学性能测试 ,并用电镜法得到其断面显微结构照片。试验结果表明 :1)与 Si C单材料断裂韧性相比 ,Si C W层状复合材料的断韧性增大 ;2 )在基体层厚度不变 ,夹层厚度为 10～ 5 0μm时 ,Si C W层状复合材料的断裂韧性随夹层厚度的增加而增大 ,而抗弯强度随之下降 ;3)材料在不同方向断裂韧性不同。 Si CW层状复合材料裂韧性增大的原因是 :1)夹层晶体颗粒大于基体层的 ,其沿晶断裂形式延长了裂纹扩展路径 ;2 )断裂过程中有晶片拨出消耗了能量 ;3)二级层状结构中片层间的微裂纹阻止了断裂裂纹的扩展
In order to analyze the toughening mechanism of Si C W layered composites, the mechanical properties of Si C W layered composites with Si C ceramic film as the base layer and W as the interlayer were tested. The microstructure of the Si C W composite was obtained by electron microscopy. The results show that: 1) Compared with the fracture toughness of Si C single material, the fracture toughness of Si CW layered composites increases; 2) When the thickness of the matrix layer is constant and the thickness of interlayer is 10 ~ 50 μm, The fracture toughness of the composites increases with the increase of interlayer thickness, while the flexural strength decreases. 3) The fracture toughness of the composites varies in different directions. The reason for the increased fracture toughness of Si CW layered composites is that 1) the intercalated crystal particles are larger than the matrix layer, and the crack growth path is extended along the intergranular fracture; 2) the wafers are dislodged during the fracture to consume energy; 3) The microcracks between the sheets in the secondary lamellar structure prevent the propagation of fracture cracks