铝合金表面不同预处理方式对其焊接质量影响研究

Study on the Influence of Different Pretreatment Methods on the Welding Quality of Aluminum Alloy Surface

为了研究铝合金表面不同预处理方式对其激光-电弧复合热源焊接质量的影响,分别对10mm厚的5083铝合金板进行了化学腐蚀、钢刷打磨和简单清洗,并利用YAG激光-MIG电弧复合热源分别对三种表面状态的铝合金板进行了焊接试验。采用体式显微镜、金相显微镜、高速相机和材料力学性能试验机分别研究了不同表面预处理方式对铝合金复合焊接焊缝成形质量、气孔率、熔滴过渡特征和力学性能的影响。研究结果表明,化学腐蚀表面状态下,工件对热源能量的吸收率最高且工件表面应力最小,进而熔池内部温度场梯度最小,激光-电弧相互作用效果最好,熔池流动性最佳,熔滴过渡频率最小,使得焊缝成形质量最好,气孔率最小,力学性能最优;钢刷打磨表面次之;原始表面最差。

To study the effect of different pretreatment methods on laser-arc welding quality of aluminum alloy surface,10 mm thick 5083 aluminum alloy plates were chemical corroded,grinded by steel brush and easy cleaned respectively,aluminum alloy plates of three types were welded by YAG laser-MIG arc hybrid welding for tests.The influence of different pretreatment methods on welding quality,porosity,droplet transfer characteristics and mechanical properties were investigated by using microscopy,metallographic microscope,high-speed camera and materials testing machine.The results showed that the sample surface which was corroded by chemistry had the highest energy absorption,the lowest surface stress,the minimum temperature filed gradient of molten pool,optimal interaction between laser and arc,the best molten pool fluidity and minimum droplet transfer frequency,it also contributed to the best formation quality of weld,the lowest porosity and optimal mechanical properties.Steel brush grinded surface was worse than chemical corroded surface,the original surface was the worst.