复合材料对LY12CZ铝合金C-环应力腐蚀性能的影响

采用铝合金C-环试样应力腐蚀试验方法，将碳纤维环氧复合材料与LYl2CZ铝合金相互偶接，研究由于电偶腐蚀的存在，对LYl2CZ铝合金应力腐蚀性能的影响，利用SEM方法对裂纹断口进行了分析。结果表明，复合材料与LYl2CZ铝合金的电偶腐蚀作用，促进了LYl2CZ铝合金C-环应力腐蚀裂纹形成与扩展，电偶作用使晶粒表面的点蚀减少，晶界腐蚀的溶解速率明显加快，晶界的二次裂纹大大增加，而与铝合金偶接的复合材料表面形貌基本无变化。

Effect of Composite Materials on the C-ring Stress Corrosion Cracking of LY12CZ Aluminum Alloy

C-ring stress corrosion method was conducted in 3. 5% NaCl solution. Graphite epoxy composite materials (GECM) and LY12CZ aluminum alloy were coupled, in order to evaluate the effect of the galvanic corrosion between GECM/LY12CZ couple on the stress corrosion cracking (SCC of LY12CZ aluminum alloy. SEM technique was used to study the microstructure of the fracture cracking. The results show that galvanic corrosion promote the formation and propagation of the stress corrosion cracking of the LY12CZ aluminum alloy C-ring samples. Pit corrosion sites are decreased, corrosion rate of the grain boundary is accelerated, and sub-cracks are increased obviously by galvanic corrosion. The surface morphology of the GECM coupled with LY12CZ aluminum alloy do not change greatly.