高功率光纤激光非熔透焊接5A06铝合金

Partial penetration welding of 5A06 aluminum alloy with high power fiber laser

为了解决高功率光纤激光非熔透焊接5A06铝合金过程中,焊接熔深的控制、合金元素的烧损、焊缝表面质量的改善等方面难以兼顾的问题,采用固定激光功率和正面焊接保护气的方法,通过改变单一焊接参量,研究了焊接速率、离焦量、搭接板间间隙的变化对焊缝表面质量的影响,并对焊缝内部镁元素的分布规律进行了理论分析和实验验证。结果表明,焊缝的硬度与镁元素的分布相一致;由于熔合线附近晶粒细化和母材镁元素扩散的共同作用,使熔合线附近的硬度高于其它部位;优化参量后的非熔透激光焊接头强度大于电弧铆焊接头,间隙为0.2mm的时候,激光焊接头强度最大,为母材抗拉强度的68.1%。这一结果对指导工业中的铝合金非熔透激光焊接是有帮助的。

In order to solve the problems such as the control of welding penetration , the loss of alloy element and weld surface quality in the process of partial penetration welding of 5A06 aluminum alloy with high power fiber laser , the effects of welding speed , defocusing amount , and lap plate gap on the quality of weld surface were studied by changing one of the welding parameters at fixed laser power and positive welding protective gas .The distribution rule of magnesium element was analyzed theoretically and verified experimentally .The test results show that weld hardness is consistent with the distribution of magnesium element.Due to the common effect of grain refinement and magnesium element diffusion of parent metal , the hardness near fusion line is greater than the other parts .The strength of laser partial penetration welding joint with optimized parameters is greater than the strength of arc riveting joint .When the clearance is 0.2mm, the strength of laser welding joint is highest and can reach 68.1%of the tensile strength of the parent material .The results are helpful to guide the partial penetration laser welding of aluminum alloy .