中文摘要：

利用X射线衍射（XRD）、带能谱（EDS）的扫描电镜（SEM）、腐蚀失重实验、极化曲线等方法,研究了1.0%La,0.7%Ce和3.0%Sm对AZ91D合金腐蚀行为的影响,并对其腐蚀机理进行了分析。结果表明：添加La,Ce和Sm后可以细化合金;在AZ91D中添加稀土元素La,Ce和Sm后,合金的自腐蚀电位高,自腐蚀电流低,阴阳极Tafel斜率大,合金耐腐蚀性能明显提高,其腐蚀速率略低于添加单一稀土元素Sm的合金。

英文摘要：

The influence of simultaneous addition of 1.0La, 0.7Ce and 3.0Sm（mass fraction, %） on corrosion behavior of AZ91 D alloy was studied by means of corrosion loss test and polarization curve as well as XRD, SEM with EDS etc, and then the corrosion mechanism was also interpreted.The results show that the addition of La, Ce and Sm can refine the alloy. After the addition of La,Ce and Sm, the AZ91 D alloy exhibited higher free- corrosion potential, lower free- corrosion current, bigger Tafel slope and higher corrosion resistance performance, but which is slightly lower than the alloy with the addition of single rare earth Sm.