(河南科技大學(xué) 材料科學(xué)與工程學(xué)院，洛陽 471003)
摘 要: 通過分析Al-7Zn-0.1Sn-0.015Ga-2Mg陽極合金中的第二相及其腐蝕特性，研究第二相對該合金腐蝕行為的影響。結(jié)果表明：Al-7Zn-0.1Sn-0.015Ga-2Mg陽極合金中的第二相主要為球狀和棒狀的MgZn2相。MgZn2相的腐蝕電位較α(Al)基體的負(fù)，腐蝕電流密度較高且極化電阻較小。MgZn2相對于α(Al)基體為陽極相，其在3.5%NaCl溶液中與α(Al)基體組成腐蝕微電池，引起MgZn2相自身優(yōu)先溶解，進(jìn)而引發(fā)合金全面溶解。
關(guān)鍵字: 鋁合金；犧牲陽極；第二相；腐蝕行為
（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
