6mm厚6061-T6铝合金双轴肩搅拌摩擦焊工艺方法研究

Study of bobbin friction stir welding process on 6 mm thick 6061-T6 Al alloy plates

针对6 mm厚6061-T6铝合金板材,设计制造了不同结构形式和尺寸规格的双轴肩搅拌摩擦焊工具,并对搅拌摩擦焊工具的结构形式和尺寸规格对焊接过程及焊接接头质量的影响进行了系统的分析研究:设计制造了两体式和三体式双轴肩搅拌摩擦焊工具,并对两种结构形式进行分析;设计制造了环状轴肩和凹面轴肩,通过焊接工艺试验得知凹面轴肩焊缝成形性优于环状轴肩;设计制造了正-反螺纹搅拌针、正螺纹搅拌针、整圆柱搅拌针和圆柱铣扁搅拌针;圆柱铣扁搅拌针焊缝焊接质量优于其他三种结构形式的搅拌针。采用凹面轴肩和圆柱铣扁搅拌针组装成的搅拌头,对6 mm厚6061-T6铝合金板材进行焊接,在主轴转速为800 r/min、焊接速度为150 mm/min工艺参数下,焊接接头得到最大抗拉强度值为220MPa,达到母材抗拉强度(315 MPa)的70%。

In order to weld 6 mm thick 6061-T6 Al alloy plate, bobbin-tools of various structural forms and sizes were designed and manufactured. The effects of structural forms and sizes on the welding process and the quality of the welded joint were analyzed. Two poses bobbin tool and three postures bobbin tool were designed and manufactured. The characteristics of the two forms of the structure were analyzed. Ring-shaped tool shoulder and concave-shaped tool shoulder were designed and manufactured. The results show that the quality of the weld by concave-shaped shoulder was better than ring-shaped shoulder. Four kinds of pin were designed and manufactured, those were pin with both right-hand thread and left-hand thread, pin with righthand thread, cylinder pin and milling flat cylindrical pin. The results show that the quality of the weld by milling flat cylindrical pin was better than others. Using bobbin tool assembled by concave-shaped shoulder and milling flat cylindrical pin, 6 mm thick 6061-T6 Al alloy plates were welded under the spindle speed of800 r/min and the welding speed of 150 mm/min. The tensile strength of the joint was 220 MPa, which was70% of base material（Rm=315 MPa）.