6061-T4铝合金无倾角搅拌摩擦焊接头组织与性能研究

Microstructure and Properties of Friction Stir Welded Joint of 6061-T4 Aluminum Alloy

采用了厚度为5 mm的6061-T4铝合金板,使用无倾角搅拌摩擦焊进行单道平板对接焊,研究了不同焊接参数对接头组织和性能的影响。结果发现,在搅拌头的焊接速度达到300 mm/min时,随着转速提升,热输入不断增加,晶粒的尺寸变大。焊接温度是影响焊核区晶粒变化的主导因素,焊缝抗拉强度先上升后下降,并在转速为1200 r/min时,焊缝的抗拉强度达到最大值200.58 MPa,为母材的93%;当转速提高至800 r/min后,试样断口均出现在焊缝前进侧热影响区。

6061-T4 aluminum alloy plate with a thickness of 5 mm was adopted,and single pass butt welding of flat plates was carried out by friction stir welding without inclination angle.The effects of different welding parameters on microstructure and properties of joints were investigated.The results indicate that when the welding speed of stirring head reaches 300 mm/min,the heat input is increased,and the grain size becomes larger with the increase of rotating speed.The grain transformation in the nugget zone is dominated by welding temperature.The tensile strength of weld is increased firstly and then decreased,which achieves the maximum value of 200.58 MPa at the rotating speed of 1200 r/min,reaching 93%of the base metal.When the rotating speed is increased to 800 r/min,fractures of specimens occurrs in the heat affected zone at the front side of the weld.