搅拌摩擦焊工艺参数窗口的建立与接头性能

Mechanical properties and welding parameters window of friction stir welding

关键词:  搅拌摩擦焊  铝合金  工艺参数窗口  接头性能  断口

Key words:  friction stir welding  aluminum alloy  mechanical property  welding parameters window  fracture

摘要:

搅拌摩擦焊的工艺参数对焊缝的表面成形和接头性能有着决定性的影响。以3 mm铝合金2024板材对接焊为代表,通过大量的工艺参数试验,考查了多种焊接参数组合下的焊接接头质量,并在此基础上建立了工艺参数窗口。结果表明,在转速375~475 r/min,焊接速度150~235 mm/min的工艺参数窗口内,接头可以获得母材80%以上的抗拉强度。通过对拉伸断口的显微分析,发现靠搅拌区上方的材料塑性较好,搅拌区底部材料抗变形能力较差,接头区沿厚度方向分层严重。

Abstract:

Friction stir welding parameters play an important role of figuration and mechanical properties of welded joint.In this study, the 3 mm plate of 2024 aluminum alloy was selected as base metal.By operating a great deal of butt welding experiments, the quality of welded joint under various parameters was tested.Furthermore, the welding parameters window was established.In the parameter of rotation speed 375-475 r min and welding speed 150-235 mm min, the tensile strength of welded joint can be higher than 80% of the one of base metal.By analyzing the tensile fracture, at the upper district of joint, the material had good plastic aspect, while the lower district was worse than the upper one.The joint showed distinct layers along the depth.