稀土镱对2519A铝合金抗晶间腐蚀性能的影响  

Influence of Yb addition on intergranular corrosion resistance of aluminum alloy 2519A

作　　者：郑玉林[1] 暨波 叶凌英[1] 张新明[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2013年第12期4806-4810,共5页Journal of Central South University:Science and Technology

基　　金：国家重点基础研究发展规划("973"计划)项目(G1999064908)

摘　　要：采用铸锭冶金法制备不同镱含量的2519A铝合金试样,通过极化曲线测试、晶间腐蚀研究、金相显微镜与透射电镜等分析方法,研究镱对2519A铝合金抗晶间腐蚀性能的影响。研究结果表明:含镱合金比不含镱合金腐蚀电流小,晶间腐蚀最大深度也减小。添加镱使析出θ′相细化,其面积分数增大,阻止θ(Al2Cu)相在晶界上连续析出,减小晶界无沉淀析出带宽度(PFZ),使晶界析出相变成非连续分布,从而提高合金的晶间腐蚀抗力。The aluminum alloy 2519A samples with different Yb additions were prepared by ingot metallurgy method, and the influence of Yb addition on corrosion resistance of aluminum alloy 2519A was investigated by polarizing curve test, intergranular corrosion study, optical microscopy （OM） and transmission electron microscopy （TEM） analytical methods. The results show that Yb addition decreases the corrosion current of aluminum alloy 2519A and reduces the maximum depth of intergranular corrosion. Compared with aluminum alloy 2519A, Yb addition can refine θ＇ phase and increase its area fraction. As a result, the continuous precipitation of θ（Al2Cu） phase in the grain boundaries can be prevented. Aslo, it can make precipitation in grain boundaries become discontinuous and lessen the width of PFZ size in grain boundaries. So intergranular corrosion of the alloy can be improved.

关 键 词：2519A铝合金 稀土 镱 晶间腐蚀 

分 类 号：TG172.9[金属学及工艺—金属表面处理]