铝片-铜管太阳能集热板超声波焊接机理研究

Study of ultrasonic welding mechanism for aluminum sheet-copper tube solar collector

在铝片-铜管太阳能集热板超声波焊接试验的基础上,首先从弹塑性理论特别是铝的应力-应变曲线导出焊接区域主要发生塑性变形,进而推导出焊接接头区域理论温度;然后通过人工热电偶试验测得铝片表面及铝片-铜管间的温度,再结合接头扫描电镜图片进行验证,认为焊接接头的形成是由材料本身的塑性本质、一定的摩擦升温、工具头竖直方向压力3个因素共同作用的结果,整个过程使接头区域材料发生充分的塑性变形,破坏并清除氧化物、油污,使焊件材料原子之间发生力的作用而形成金属键合。

Basing on the experiment of aluminum sheet-copper tube solar collector ultrasonic welding, this paper firstly concluded from elastic-plastic theory especially stress-strain curve of aluminum that the main change in welding region was plastic deformation, then that the theoretic temperature of the region; secondly, by using thermocouple and scanning electron microscopy, temperatures of aluminum surface and the area between copper tube and aluminum sheet were obtained and testified, all of which proved that the forming of the welded joint is determined by the material's plastic nature, friction heating-up and the vertical pressure of the tool head, the whole process makes the plastic deformation happen in welded joint region, destroys oxid and oil pollution then makes atoms of welding material metal bond because of force.