【摘要】 镀锌板以其优良的抗腐蚀性能而大量应用于汽车工业中 ,由于锌的熔点和气化温度较低 ,在焊接加热过程中极易挥发 ,从而导致气孔、裂纹等焊接缺陷 ,给镀锌板的焊接带来很大问题。激光填丝钎焊的低热输入与小加热区域的特点可有效解决镀锌板焊接的上述问题。本文研究了激光功率、光斑直径、加热时间等对钎料在镀锌板表面铺展行为的影响 ,并在此基础上对卷对接接头、对接接头、搭接接头的激光填丝钎焊工艺特点进行了试验研究 ,分析了镀锌板激光填丝钎焊的主要缺陷及其关键影响因素。更多还原

【Abstract】 Galvanised thin sheets is widely applied in automobile industry because of its favorable corrosion resistance and cost. The low melting and evaporating point of zinc make it strongly evaporate during fusion welding process, and lead to the problems of pores and crack. A new technique of laser brazing with automated wire feed was presented in this paper, which can solve the problems of welding galvanized thin sheets. The influence of laser power, spot diameter and heating time on the wetting and spreading behavior of brazing filler metal on the surface of galvanized thin sheets were presented at first. Moreover, aiming to the butted joint, flange butt joint and lap joint, the welding characteristics of laser brazing with automated wire feed were investigated, the main welding defects were also analyzed in this paper.更多还原