6061-T6铝合金高速高功率CO_2激光填丝焊接性的研究

Research on High Speed High Power CO_2 Laser Welding of 6061-T6 Aluminum with Filler Wire

为实现6061－T6铝合金薄板的高速高功率CO2激光填丝焊接，选用了ER4043，ER5356两种焊丝进行了焊接性试验。利用鱼骨状试样对两种焊丝的激光焊接铝合金6061-T6的热裂纹敏感性进行了分析；利用金相显微镜、扫描电镜、显微硬度计以及万能材料试验机分析了焊接接头的组织与性能。研究结果表明，与填充ER5356焊丝相比，填充ER4043焊丝的焊接接头热裂纹敏感性较低，焊接速度可达6m／min。焊缝主要是柱状晶、等轴晶及少量树枝晶，显微硬度在60－80HV，拉伸强度可达240～262MPa，弯曲性能良好。

In order to realize the high power CO2 laser welding of 6061-T6 aluminum alloy sheet under high travel speed, filler wire ER4043 and ER5356 are selected for welding. In the experiments, welding hot cracking sensitivity is analyzed by use of fishbone samples, and optical microscope, scanning electron microscope, micro-hardness test and mechanical property test are applied to analyze the microstructure and properties of the joints. Results indicate that compared with filling wire ER5356, the hot crack sensibility of the joint welded with wire ER4043 is lower, and a maximal welding speed of 6 m/min can be reached. The weld contains columnar grains, equiaxes grains, and some dendrites grains. The weld has a micro-hardness of joint with ER4043 of 60- 80 HV, a tensile strength of 240-262 MPa and a good bending property.