【摘要】 利用扫描电镜(SEM)结合能谱分析(EDS)、X射线衍射(XRD)、腐蚀失重实验、电化学极化曲线等方法,研究了0.1%,0.4%,0.7%和1.0%的Sm对AZ91D合金的微观组织和腐蚀性能的影响,并对其腐蚀机理进行分析。结果表明:随着Sm含量的增加,合金中粗大的枝状第二相(β-Mg17Al12)逐渐断裂变小,其体积分数下降,因为Sm会结合Al形成颗粒状的Al2Sm和杆状的Al3Sm,从而减少晶界处第二相的数量,使第二相呈不连续分布;AZ91D的耐腐蚀性随着Sm加入量的增多,先增加后降低;当Sm加入量为1.0%时,合金的耐腐蚀性与不添加Sm的AZ91D接近;Sm的最佳添加量为0.4%。更多还原

【Abstract】 The influence of 0.1%, 0.4%, 0.7% and 1.0% Sm addition on microstructure and corrosion property of AZ91 D alloy was studied by means of SEM with EDS, XRD, corrosion weight loss test and electrochemical polarization curve etc. The results show that with the increasing Sm content, the bulky dendritic second phase(β- Mg17Al12) in the alloy becomes finer and the volume fraction of which decreases gradually, whilst Sm may combine with Al to form granular Al2 Sm and rod-shaped Al3 Sm, thereby, cutting down the number of the second phase in grain boundaries, leading to the second phase discontinuous distribute; Sm can improve the corrosion resistance of alloy,but the corrosion resistance firstly increases and later decreases with the increasing Sm content.The corrosion resistance of the alloy with 1.0% Sm is close to the bare AZ91 D. The optimum addition amount is 0.4% Sm for the highest corrosion resistance.更多还原