CO_2激光焊接快速凝固耐热铝合金AA8009  

Rapid solidified heat-resistant aluminum alloy AA8009 by CO_2 laser welding

作　　者：丁荣辉[1] 黎文献[1] 王日初[1] 肖于德[1] 马正清[1] 余琨[1] 路彦军[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）》2006年第2期217-222,共6页Journal of Central South University:Science and Technology

基　　金：国家"十五"科技攻关项目(TG1999064912)

摘　　要：采用3种不同的焊接速度（0.6, 1.5和2.4 m/min）, 对板厚为1 mm的耐热铝合金AA8009进行CO2激光焊接. 研究结果表明： 在焊接冷却速度为102～103 ℃/s时, 焊缝中心凝固组织为亚共晶组织, 大量细小的第二相粒子弥散分布在细小近等轴的α-Al中;在熔化区边界存在大量粗大的针状相分布在粗大胞状枝晶α-Al中;提高焊接速度可改善焊接接头组织和性能, 当焊接速度为2.4 m/min时, 焊缝组织类似于基材组织;焊接接头断裂发生在熔化区边界.Three kinds of welding speed（0.6, 1.5 and 2.4 m/min） were used to joint the heatresistant aluminum alloy AA8009 plate with 1 mm in thickness by CO2 laser welding. The results show that when the cooling rate of the heat-resistant aluminum alloy by CO2 laser welding is 102 - 103℃/s, at the center of the fusion zone, the structure exhibits hypoeutectic morphology, and a large number of fine second phases precipitate in the fine equiaxed α-Al matrix; near the fusion boundary there is a lot of coarse needle-like phases existing in the coarse cellular α-Al matrix. The higher the welding speed is, the better the welding structure and performance are. When the welding speed is 2.4 m/min, the microstructure of center region is similar to that of base metal; the fractures of the welded joints occur in the fusion boundary region.

关 键 词：快速凝固 耐热铝合金AA8009 CO2激光焊接 

分 类 号：TG439.4[金属学及工艺—焊接]