材料性能对铝合金搅拌摩擦焊焊缝成形的影响

发布时间：2018-01-16 15:24

本文关键词：材料性能对铝合金搅拌摩擦焊焊缝成形的影响　出处：《南昌航空大学》2017年硕士论文　论文类型：学位论文

【摘要】：本课题采用自主设计的左螺纹圆柱形搅拌头对10mm厚的1060纯铝、5A06和7075铝合金进行同种及异种材料搅拌摩擦焊对接实验,通过同种材料对接,研究材料性能和焊接工艺参数对搅拌摩擦焊焊缝成形及接头抗拉强度的影响;通过异种材料和同种材料异种状态的对接焊和叠层焊接,研究了材料性能对焊缝塑性金属流动行为的影响规律。研究结果表明:随着被焊材料强度、硬度的增大,焊接速度和搅拌头旋转速度对焊缝成形的影响强度增大。强度、硬度低的材料获得良好焊缝成形的可选择工艺参数范围更广,且不容易出现缺陷。强度、硬度高的材料则只能在较窄的工艺参数范围内形成良好的焊缝。在相同的焊接工艺参数下,被焊母材性能不同时,焊核尺寸表现出不同的规律。在一定范围内,增大搅拌头旋转速度和减小焊接速度都会使焊核尺寸变大。同种材料搅拌摩擦焊接时,强度、硬度低的材料,焊缝周围金属对焊缝塑性金属的约束作用力小,焊核尺寸和面积较强度、硬度高的材料更大。异种材料焊接时,在焊接参数相同的情况下,搅拌针表面螺纹与强度、硬度低的材料的焊缝金属过早地发生滑动摩擦导致驱动力不足,焊核宽度和面积更小,焊缝中心向强度、硬度高的材料一侧偏移。同种材料的异种状态叠层实验发现,不同厚度的焊缝横截面表现出不同的形貌,轴肩作用区金属变形程度最大且在两种金属汇合程度较大的紊流区产生缺陷。搅拌针两侧金属层发生较大变形且厚度减小,其中强度、硬度低的材料减小的程度更大。
[Abstract]:This topic uses the left threaded cylindrical designed mixing head on 1060 pure aluminum 10mm thick, 5A06 and 7075 Aluminum Alloy were stirring friction welding docking experiments of similar and dissimilar materials, by the same material docking, the effects of material properties and welding parameters on friction stir welding of tensile strength and joint shape by butt welding; dissimilar materials and the same material dissimilar state and laminated welding, studied the influence of weld material properties of plastic metal flowing behavior. The results show that with strength of welding materials, hardness increases, influence of welding speed and rotational speed on the weld strength. Strength, low hardness of the material good weld can be more a wide range of process parameters, and not prone to defects. The strength, the hardness of the material is only in a narrow range of process parameters to form a good The weld in the same welding parameters, welding performance is not at the same time, the nugget size showed different rules. In a certain range, increasing the rotating speed and the decrease of welding speed will make the weld nugget size. Friction stir welding of the same material, strength, low hardness material and around the weld metal on the weld metal plastic constraint force is small, the nugget size and area compared with the strength and hardness of the material is larger. Welding of dissimilar materials, the welding parameters are the same, the pin thread surface and strength of weld metal materials to premature low hardness of the sliding friction caused the lack of driving force, welding width and smaller area, to the center of weld strength, material side offset high hardness. Found dissimilar laminated materials of the same kind of experimental condition, the weld cross section with different thickness exhibit different morphology, shoulder region The deformation degree of metal is the largest and the defect occurs in the turbulent area where the two metals converge. The metal layer on both sides of the stirred needle has larger deformation and thickness decreases, and the material with lower strength and hardness decreases more.

【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG453.9

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