稀土元素对Zn-5Al-2Mg-0.5Si合金微观组织和性能的影响

Effect of Rare Earth Elements on Microstructure and Properties of Zn-5Al-2Mg-0.5Si Alloy

为了开发新型高耐腐蚀热浸镀锌合金材料,使用微合金化方法将稀土元素添加到Zn-5Al-2Mg-0.5Si合金中,并对试样的微观组织、腐蚀性能、硬度和腐蚀产物进行了分析和表征。结果表明:稀土元素的加入可以为合金提供异质形核核心,增加形核数目,细化晶粒,提高合金的硬度。另外稀土元素还可以增加电荷转移的阻力,降低腐蚀反应的驱动力,促进腐蚀产物中Zn_(5)(OH)_(6)(CO_(3))_(2)的生成,该物质可能与合金腐蚀性能的提高紧密相关。

To develop a new type of hot dip galvanized alloy material with high corrosion resistance,rare earth elements were added to Zn-5Al-2Mg-0.5Si alloy by microalloying method,and the microstructure,corrosion properties,hardness and corrosion products of the sample were analyzed and characterized.The results show that the addition of rare earth elements can provide the heterogeneous nucleation core for the alloy,increase the number of nucleation,refine the grain and improve the hardness of the alloy.Rare earth elements can also increase the resistance of charge transfer,reduce the driving force of corrosion reaction,promote the formation of Zn_(5)(OH)_(6)(CO_(3))_(2) in the corrosion products,which may be closely related to the improvement of corrosion performance of the alloy.