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为提高 Si C颗粒增强铝基复合材料 Al 2 12 4的耐蚀性 ,采用 X射线衍射、扫描电镜和电化学测试等手段 ,研究了 3种热处理工艺 (T1,T4和 T6 )对复合材料中第二相化合物的析出状况以及该材料在 Na Cl水溶液中的腐蚀行为的影响。结果表明 ,在 T1状态下 ,铝合金基体内及 Si Cp/铝合金界面上析出大量以 Cu Al2 为主的第二相化合物 ,导致复合材料表面点蚀活性位置增多 ,点蚀敏感性增大 ;但是 ,T6和T4热处理显著减少 Cu Al2 相析出并大幅度降低复合材料的点蚀敏感性。 3种热处理状态下 Si Cp/Al 2 12 4复合材料的耐点蚀性能可依下列顺序提高 :T1,T6 ,T4。
In order to improve the corrosion resistance of Al 2 12 4 reinforced with Si C particles, the effects of three heat treatments (T1, T4 and T6) on the corrosion resistance of the composite were investigated by X-ray diffraction, scanning electron microscopy and electrochemical measurements. The precipitation behavior of the second phase compound and the corrosion behavior of the material in NaCl aqueous solution. The results show that a large amount of second phase compounds mainly containing Cu Al2 are precipitated in the Al matrix and at the interface of Si Cp / Al alloy, which leads to the increase of pitting corrosion activity and pitting sensitivity of the composite. However, T6 and T4 heat treatment significantly reduce the Cu Al2 phase precipitation and significantly reduce the pitting sensitivity of the composite. The pitting corrosion resistance of Si Cp / Al 2 12 4 composites under three heat treatments can be improved in the following order: T1, T6, T4.