【摘要】 用CO2激光对4 mm厚的AZ31B变形镁合金进行了焊接试验,试验中出现了三种焊接模式:小孔焊、热导焊、模式不稳定焊。分析发现在一定参数范围内激光功率是焊接模式的决定因素。提出用正面熔宽与纵深段熔深的比值来表征小孔焊焊缝的形状特点,并对焊缝形状参数的影响因素进行了分析。发现焊接热输入是控制焊缝形状的最主要因素,而焊接速度变化引起的激光能量利用率的变化和激光功率变化引起的等离子体羽翼导热影响范围的变化也是焊缝形状的影响因素。在保证熔透的前提下,选择较低的激光功率、较高的焊接速度和较弱的焊接规范有利于获得深而窄的焊缝。更多还原

【Abstract】 4 mm thickness plates of AZ31B alloy were welded by CO2 laser.Three welding modes of deep penetration welding,heat conduction welding and unstable mode welding were found,and laser power was found to be the main factor for welding mode.The ratio of topside width and penetration of "deep and narrow segment" was proposed to characterize the weld shape,and the influencing factors of weld shape were investigated.Heat input was found to be the most important factor,while the laser power efficiency affected by welding velocity and the size of plasma-flume-affected zone affected by laser power could also influence the weld shape.When welds are fully penetrated,low laser power,high welding velocity and parameter combination of low laser power and welding velocity is favorable for weld of deep and narrow shape.更多还原