搅拌摩擦焊下压力控制系统的开发及在模拟非刚性环境下的验证试验

发布时间：2018-11-08 19:28

【摘要】：搅拌摩擦焊接(Friction stir welding,FSW)是材料固态连接新技术,但FSW在焊接过程中一般会对工件施加较大的下压力,焊接设备和被焊工件在下压力的作用下均可能产生变形,使得常规FSW中设定的下压量这一关键参数偏离预期值,无法保证焊接工艺的稳定性。为了解决这一问题,开发一套下压力反馈控制系统,通过调节搅拌头对工件的下压量来调节下压力,使焊接过程中下压力保持稳定。该系统使用一台计算机作为顶层控制器,根据压力传感器反馈的实时下压力调节FSW设备Z轴的进给。使用该系统在悬空的钢板上焊接6082-T6铝合金平板对接焊缝,焊接过程中工件在下压力的作用下产生的弯曲变形高达0.931 mm,但所得的焊缝成形良好,沿焊缝方向不同位置的接头的横截面形貌基本一致,其横向拉伸应力应变曲线高度重合,接头的平均抗拉强度为222.8 MPa。结果表明,工件在下压力作用下产生变形的条件下,下压力控制的FSW系统仍能保证工艺稳定性。
[Abstract]:Friction stir welding (Friction stir welding,FSW) is a new technology for solid-state bonding of materials. However, in the process of welding, FSW usually exerts a large downward pressure on the workpiece, and the welding equipment and the welded workpiece may deform under the action of the downward pressure. The key parameter of the lower pressure set in conventional FSW deviates from the expected value, which can not guarantee the stability of welding process. In order to solve this problem, a feedback control system for downward pressure is developed, which adjusts the downward pressure by adjusting the pressure of the mixing head to the workpiece, so as to keep the downward pressure stable in the welding process. The system uses a computer as the top controller and adjusts the Z axis feed of FSW equipment according to the pressure sensor feedback. Using the system to weld the 6082-T6 aluminum alloy plate butt weld on the suspended steel plate, the bending deformation of the workpiece under lower pressure is up to 0.931 mm, during the welding process, but the weld formed well. The cross section morphology of the joints with different positions along the weld direction is basically the same. The transverse tensile stress-strain curves are highly overlapped, and the average tensile strength of the joints is 222.8 MPa.. The results show that the process stability can be guaranteed by the FSW system controlled by the lower pressure when the workpiece is deformed under the lower pressure.
【作者单位】：清华大学机械工程系;清华大学摩擦学国家重点实验室;
【分类号】：TG453.9

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