焊接方式对铝合金搅拌摩擦焊T型接头性能的影响

Effects of Welding Ways on Properity of Aluminum Alloy T-Joint During Friction Stir Welding

采用4种规格的搅拌头进行了2A70-T6铝合金T型接头搅拌摩擦焊试验,并对焊缝横截面进行了观察以及焊缝抗拉强度的测试。结果表明:焊缝中前进侧熔合过渡区的金属变形比返回侧剧烈,焊缝断裂往往发生在前进侧;在相同的焊接参数下,单道焊缝的焊核宽度与抗拉强度随着搅拌针直径的增大而增大,但增大的幅度较小,并列焊的焊缝抗拉强度仅为单道焊缝的93%左右;为了获取相同宽度的焊核,采用加粗搅拌针单道焊比并列焊更具有优势。

Friction stir welding for T-joint of 2A70-T6 aluminum alloy is carried out by using four different kind of welding tools, the weld cross section is observed and the tensile strength of weld is tested. The results show that the transition metal at the advancing side deform excessively compared to the retreating side. The joints often break at the advancing side, under the same welding parameter. The nugget width and the tensile strength increase along with the diameter of the pin increases in the single-passs weld, but the increment is small. The tensile strength of parallel weld is about 93 % of the single-pass weld. In order to get the same width nugget, it is advantage to adopt single-pass weld- ing by using big diameter pin over parallel welding.