基于复合搅拌摩擦焊的6063铝合金焊接接头残余应力控制研究

Study on Residual Stress Control of 6063 Aluminum Alloy Welded Joint Based on Composite Friction Stir Welding

分别采用普通搅拌摩擦焊和带随焊旋转滚压装置及随焊水雾冷却装置的复合式搅拌摩擦焊对6063铝合金薄板进行焊接试验,并对两组试验的纵向残余应力数据进行对比分析。试验结果表明：普通搅拌摩擦焊接焊后试样的最大纵向残余应力是拉应力,其值为83.6 MPa,位于前进侧的搅拌头轴肩边缘处。前进侧与返回侧两侧的纵向残余应力基本对称,从焊缝中心到边缘,纵向残余应力由小变大后再变小,最后转变为压应力;复合搅拌摩擦焊接焊后试样的最大纵向残余应力比普通搅拌摩擦焊减小了38.9 MPa,其分布与普通搅拌摩擦焊时基本相同,但其变化范围窄。这说明随焊旋转滚压装置及随焊水雾冷却装置能有效减小纵向残余应力,从而能减小焊后变形,提高搅拌摩擦焊接接头质量。

The common friction stir welding and composite friction stir welding with rotary rolling device and water mist cooling device of 6063 aluminum alloy thin plate were carried out, and the longitudinal residual stress data of the two groups were compared and analyzed. The test results show that the maximum longitudinal residual stress of the welded specimen after commonl friction stir welding is tensile stress, which is 83.6 MPa, and it appears at the edge of mixing head shoulder at advancing side. The longitudinal residual stresses at advancing side and retreating side are basically symmetrical, and it changes from small to large then small, then changes to compressive stress from the weld center to the edge. The maximum longitudinal residual stress of the specimen welded by composite friction stir welding is 38.9 MPa lower than that of the specimen welded by common friction stir welding. Its distribution is basically the same as that of common FSW, but its variation range is narrow. It shows that the rotating roller device and water mist cooling device can effectively reduce the longitudinal residual stress, thus reducing the deformation after welding and improving the quality of friction stir welded joints