焊接参数对6061-T6铝合金薄板的HR-FSW轴向力的影响

采用高转速搅拌摩擦焊接(HR-FSW)方法实现了1mm厚6061-T6铝合金薄板的对接试验,研究了焊接速度对轴向力和力学性能的影响。试验结果表明:焊接速度对轴向力起到决定性的作用,焊接轴向力随着焊接速度的增加而增加;当轴向力处于0.9-1 kN之间(焊接速度为200-300 mm/min)时,焊接接头组织均匀,力学性能较好;在主轴转速为10000 r/min,焊接速度为300 mm/min,轴肩下压量为0.06 mm下可以获得最佳焊缝,其组织均匀,外表成型美观、无焊接缺陷,抗拉强度达到201.92 MPa,约为母材的70%。

轴肩直径对6061铝合金搅拌摩擦焊轴向力的影响

目的降低搅拌摩擦焊接过程中的轴向力,选择直径合适的轴肩,提高搅拌摩擦焊的焊接效率以及接头性能。方法设计并使用了3种不同轴肩直径的搅拌头(9,12,15 mm)对6061铝合金进行焊接,记录并分析焊接轴向力的变化,观察焊缝表面形貌及微观组织,选择合适的轴肩直径。结果“轴向力-时间”曲线上下起伏,当轴肩直径为15 mm时,曲线呈现较大的起伏;随着轴肩直径的减小,焊接轴向力也随之减小,当焊接速度为95 mm/min,搅拌头旋转速度为1500 r/min时,轴肩直径为9 mm的搅拌头所产生的平均轴向力最小,最小值约为2311 N;9 mm轴肩焊接所形成的焊缝表面形貌光滑,飞边量少;轴肩直径越小,焊核区晶粒尺寸越细小,当轴肩直径为9 mm时,焊核区晶粒尺寸为9.77μm。结论在相同的焊接参数下,选用9 mm轴肩所产生的轴向力小,焊缝表面形貌优,焊核区晶粒尺寸细化,接头力学性能好。

Effect of process parameters on tensile strength of friction stir welded cast A356 aluminium alloy joints

A356 is a high strength aluminium-silicon cast alloy used in food,chemical,marine,electrical and automotive industries.Fusion welding of this cast alloy will lead to many problems such as porosity,micro-fissuring,and hot cracking.However,friction stir welding（FSW） can be used to weld this cast alloy without above mentioned defects.An attempt was made to study the effect of FSW process parameters on the tensile strength of cast A356 aluminium alloy.Joints were made using different combinations of tool rotation speed,welding speed and axial force.The quality of weld zone was analyzed by macrostructure and microstructure analyses.Tensile strengths of the joints were evaluated and correlated with the weld zone hardness and microstructure.The joint fabricated using a rotational speed of 1000 r/min,a welding speed of 75 mm/min and an axial force of 5 kN showed a higher tensile strength compared to the other joints.