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采用纤维涂层+热等静压的工艺方法制备出了SiC纤维增强GH4738复合材料,并应用SEM、XRD、TEM对复合材料制备过程中发生的界面反应进行了分析研究。结果显示:在热等静压过程中,SiC纤维与GH4738发生了剧烈的界面反应,反应层厚度可达25μm,反应产物主要为Ni_2Si、Cr_(23)C_6和C;从热力学和动力学对界面反应机理进行了分析,理论计算结果与试验结论符合性较好。对复合材料中纤维进行了顶出试验,从断口可以看出界面反应导致纤维性能剧烈损伤,生成的脆性界面反应产物易成为缺陷、裂纹萌生扩展的源区。
The SiC fiber reinforced GH4738 composite was prepared by fiber coating and hot isostatic pressing. The interfacial reactions occurred during the preparation of the composites were analyzed by SEM, XRD and TEM. The results show that during the process of hot isostatic pressing, the interface between SiC fibers and GH4738 undergoes intense reaction, the thickness of the reaction layer is up to 25μm, and the reaction products are mainly Ni_2Si, Cr_ (23) C_6 and C. The thermodynamics and kinetics of interfacial reaction The reaction mechanism is analyzed, the theoretical calculation results are in good agreement with the experimental conclusion. Fibers in the composite material were tested for the ejection test. It can be seen from the fracture that the interfacial reaction led to severe damage to the fiber properties. The resulting brittle interface reaction products easily became the source region for defects and crack initiation and propagation.