采用失重法、极化曲线、电化学阻抗谱和腐蚀形貌等方法研究了微量Sb对Mg-5A1—2Sr合金在3．5mass％NaCl中性水溶液中耐腐蚀性能的影响。结果表明，Mg-5A1—2Sr—xSb（x=O，0．3，O．6，1．0）合金在3．5mass％NaCl中性水溶液中初期的腐蚀类型为点蚀，点蚀源于块状三元T相和颗粒状SbSr2相。这些相的数量越多，尺寸越大，合金的腐蚀愈严重。网状分布的A14Sr相能够成为合金腐蚀的有效障碍。Mg-5Al-2Sr合金中加入0．3％Sb不仅能够有效地细化OL—Mg基体组织，同时促进了A14Sr相的形成，使该相的分布更趋网状化，该合金的自腐蚀电位明显正移，腐蚀电流密度减小，腐蚀速率降低，合金的耐蚀性能提高。
Corrosion weight loss, polarization techniques, electrochemical impedance spectroscopy(EIS) and corrosion morphology were used to estimate the impact of Sb addition on corrosion properties of Mg-5Al-2Sr alloys in 3.5% NaCl solution. Experimental results show that the initial corrosion types of Mg-5Al-2Sr-xSb(x=0, 0.3, 0.6, 1.0) alloy in 3.5% NaCl solution is pitting corrosion. Pitting originated in massive ternary τ phase and granular SbSr2 phase. The larger amount and the bigger size of these phases corresponds to the poorer resistance. Mesh distribution A14Sr phase can become an effective barrier of corrosion. Adding 0.3% Sb not only refines the α-Mg matrix of Mg-5Al-2Sr alloy, but also promotes the formation of Al4Sr phase which distributed more in network. The corrosion potential of the alloy shifts positive obviously, the corrosion current density and corrosion rate reduces, thus, the corrosion resistance of the alloy is improved.
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