中文摘要：

通过电子背散射衍射（EBSD）对微合金化的铝合金A356的晶粒尺寸、晶界类型、晶界特性进行了研究,探究微合金化后晶粒尺寸和晶界特性对铝合金耐蚀性能的影响机制。研究结果表明：随着元素比例的变化,晶粒的尺寸、晶界中特殊晶界特征和比例以及晶界的取向差角都发生了明显改变;当元素比例达到La质量分数0.15%、Y质量分数0.2%时,晶粒细化最为明显,Σ3晶界所占比例最高,小角度晶界所占比例明显提高,耐腐蚀性显著增强。

英文摘要：

Electron backscatter diffraction（ EBSD） experiments have been conducted to study grain size and grain boundary types in aluminium alloys.Electrochemical measurements were used to study the corrosion resistance of aluminum alloys,and explore how this is affected by crystal grain boundaries.The results show that changes in elemental composition result in significant changes in grain size,special grain boundaries,and the proportion as well as the orientation angle in grain boundaries.When the elemental mass fractions of La and Y were 0.15% and0.2% respectively,the most obvious grain refinement occurred,Σ3 accounted for the highest proportion of grain boundaries,and the proportion of small- angle grain boundaries led to significantly improved corrosion resistance.