含铒铝合金TIG焊接头组织与性能  

Microstructure and properties of Er-containing aluminum alloy TIG weld joints

作　　者：靳立坤[1] 李晓延[1] 贺定勇[1] 蒋建敏[1] 杨东霞[2] 聂祚仁[2] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124 [2]北京工业大学新型功能材料教育部重点实验室,北京100124

出　　处：《焊接学报》2011年第8期85-88,117,共4页Transactions of The China Welding Institution

基　　金：国家863高技术研究发展计划基金资助项目(2009AA03E516;2009AA0303801)

摘　　要：为了研究Er元素对焊缝的强化作用及机理,对含Er元素铝合金进行TIG重熔焊试验,通过对接头组织结构观察和力学性能测试,发现在焊缝的晶界处有初生Al3Er相析出,但与母材相比析出相数量较少,在晶界处未形成连续的环状,次生Al3Er相在焊缝中也有析出,但数量极少,Er元素将以固溶态和偏析的形式存在.Er元素对焊接接头的强化作用主要以初生相Al3Er粒子的细晶强化为主,而次生相对位错和亚晶界的钉扎作用很小.结果表明,Er元素对焊缝的强化作用有限,焊接接头力学性能明显下降,焊接接头的抗拉强度为297 MPa,是母材强度的72%,拉伸断裂位置主要是分布在焊缝中心或熔合区附近.To study the strengthening effect and mechanism of Er element on the weld, the remelting welding of Al-Mg alloy with Er was adopted, and the organizational structure and mechanical properties of the joint were observed. The results show that there is primary Al3Er phase precipitation on the grain boundaries in weld, but the quantity of it is fewer than that of in the base material, and the precipitation doesn't form a continuous ring. The secondary Al3Er precipitation also can be found in the welding, but the precipitation phase quantity is very few. Er elements will presence in the solid solution or segregation way. The strength of Er element on the weld joint is mainly based on the primary Al3Er to refine the grain. The effect of the secondary phase on the weld joint is small, and so the weld joint mechanical properties decrease evidence. The tensile strength of welded joints is 297 MPa, and the strength coefficient of welded joints is 72% of base material. Tensile fracture position is mainly in the center of the weld and near the fusion zone.

关 键 词：初生相 次生相 细晶强化 析出强化 

分 类 号：TG146.2[一般工业技术—材料科学与工程]