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研究了可降解Zn-7Mg合金经不同时间热处理后的显微组织演变及耐蚀性能。设计了锌镁合金Zn-7Mg材料,通过改变热处理时间获得Mg_2Zn_(11)相。通过EDS和ICP确定了锌镁合金的成分,运用OM和SEM分析合金的微观组织,利用XRD谱表征合金的物相组成,采用电化学方法测试合金的耐蚀性能。结果表明,Zn-7Mg合金在铸态时主要由α-Zn和MgZn_2两相组成,热处理时包晶反应迅速发生。Zn-7Mg合金热处理后的平衡组织为Mg_2Zn_(11)相和少量残余的Mg Zn2相;电化学开路电位和电化学阻抗谱分析表明,Mg_2Zn_(11)在PBS溶液中的耐腐蚀性能较纯Zn差,在实际生产中应避免Mg_2Zn_(11)的产生。
The microstructure evolution and corrosion resistance of degradable Zn-7Mg alloy after different heat treatments were studied. The Zn-7Mg material was designed and the Mg_2Zn_ (11) phase was obtained by changing the heat treatment time. The composition of zinc-magnesium alloy was determined by EDS and ICP. The microstructure of the alloy was analyzed by OM and SEM. The phase composition of the alloy was characterized by X-ray diffraction (XRD) and the corrosion resistance of the alloy by electrochemical method. The results show that the as-cast Zn-7Mg alloy mainly consists of α-Zn and MgZn 2 phases, and the peritectic reaction occurs rapidly during the heat treatment. The equilibrium structure of Zn-7Mg alloy after heat treatment was Mg 2 Zn 11 phase and a small amount of residual Mg Zn 2 phase. Electrochemical open circuit potential and electrochemical impedance spectroscopy analysis showed that the corrosion resistance of Mg 2 Zn 11 in PBS solution was better than pure Zn Poor, in the actual production should avoid the production of Mg_2Zn_ (11).