Zn、Sb、Ti、Zr对ZL114合金腐蚀性能的影响

The influences of Zn、Sb、Ti、Zr on the corrosion of ZL114A alloy

采用电化学腐蚀试验和浸泡腐蚀试验研究了铸造铝硅合金在3.5%NaC1溶液中的腐蚀行为,同时还探讨了合金元素Zn、Sb、Ti、Zr对ZL114合金开路电压、腐蚀电流密度和腐蚀性能的影响规律,并利用金相显微镜和扫描电镜对合金浸泡腐蚀前后的形貌进行了观察与分析。电化学试验结果表明,试验合金的自腐蚀电位向负向移动,腐蚀电流密度增加。浸泡腐蚀试验结果表明,加入合金元素降低了ZL114的腐蚀性能,其中Zn影响较大。

The corrosion behaviour of cast Al - Si alloys in 3.5 % NaCl solution has been studied by electrochemical and immersion corrosion tests, at the same time. the effect of Zn. Sb, Ti and Zr on Corrosion potentials, corrosion current densities and corrosion properties of ZL114 alloys have been investigated in this paper. The morphologies of tested alloys before and after immersion corrosion were analyzed by SEM （ scanning electron microscopy）. The results of electrochemistry tests indicate that all the tested alloys may be passivated rapidly. The free corrosion potentials shifted to negative and the corrosion current densities of the alloys increased with the increasing of alloy elements, The results of immersion corrosion tests show that corrosion resis- tance of ZL114 alloy is decreased when it contains the testing alloy elements, especially the Zn.