(河南科技大学 材料科学与工程学院，洛阳 471003)
摘 要: 通过分析Al-7Zn-0.1Sn-0.015Ga-2Mg阳极合金中的第二相及其腐蚀特性，研究第二相对该合金腐蚀行为的影响。结果表明：Al-7Zn-0.1Sn-0.015Ga-2Mg阳极合金中的第二相主要为球状和棒状的MgZn2相。MgZn2相的腐蚀电位较α(Al)基体的负，腐蚀电流密度较高且极化电阻较小。MgZn2相对于α(Al)基体为阳极相，其在3.5%NaCl溶液中与α(Al)基体组成腐蚀微电池，引起MgZn2相自身优先溶解，进而引发合金全面溶解。
关键字: 铝合金；牺牲阳极；第二相；腐蚀行为
（School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China）
Abstract:Influence of the second phase on the corrosion behavior of Al-7Zn-0.1Sn-0.015Ga-2Mg alloy was investigated through the analysis of the second phase and its corrosion characteristics in Al-7Zn-0.1Sn-0.015Ga-2Mg alloy. The results show that the second phases in Al-7Zn-0.1Sn-0.015Ga-2Mg alloy mainly are MgZn2 particles with spherical and rod-like. MgZn2 has a more negative corrosion potential, a higher corrosion current density and a smaller polarization resistance than α(Al) matrix. The MgZn2 particles are the anodic phase relative to α(Al) matrix, they form many micro-corrosion cells with α(Al) matrix in 3.5% NaCl solution, which lead to the anodic self-dissolution of MgZn2 particles preferential, and resulting in the whole dissolution process of the aluminum sacrificial anode.
Key words: aluminum alloy; sacrificial anode; second phase; corrosion behavior
