为研究能量配比系数(激光功率与电弧功率的比值)对铝合金激光-MIG复合焊接气孔的影响,采用X射线无损检测与金相显微组织观察法对6 mm厚6061铝合金激光-MIG复合焊接接头在能量配比系数为4.0、3.5、3.1下的气孔进行了分析。结果发现:激光功率对焊缝横截面底部熔宽的影响显著,增大电弧功率能有效增大复合作用区域的深度;在较高的能量配比系数下,焊缝内部气孔的直径较大,但其数量较少,气孔率较低;在焊缝横截面上,气孔主要分布在焊缝上部,下部较少;但是当能量配比系数降低至3.1时,气孔的分布趋于均匀,下部气孔数量增加显著,且工艺气孔的数量也有所增加。结果表明,提高激光功率的能量占比有利于降低气孔率。

To study the effect of energy ratio coefficient (the ratio of laser power to arc power) on pores during the aluminum alloy laser-MIG hybrid welding process, 6 mm thick 6061 aluminum alloy laser-MIG hybrid welded joints were measured using X-ray nondestructive testing and metallographic microstructure observation. Pores under the energy ratio coefficient of 4.0, 3.5, and 3.1 were analyzed. It was observed that the laser power has a significant effect on the bottom weld width in the cross-setion of the weld and increasing the arc power can effectively deepen the hybrid zone. Under the higher-energy ratio coefficient, the diameter of the pores inside the weld is larger, but the number of pores is smaller, contributing to low porosity. The pores in the weld cross-section are mainly distributed in the upper part of the weld and less in the lower part. However, when the energy ratio coefficient is reduced to 3.1, the distribution of pores tends to be uniform, the number of pores in the lower part significantly increases, and the number of process pores increases. These results show that increasing the energy ratio of laser power during laser-MIG is beneficial to reduce the porosity.