激光焊接工艺对QAl11-6-6铜合金焊接接头显微组织的影响

Effect of Laser Welding Technology on Microstructure of QAl11-6-6 Copper Alloy Welded Joint

采用金相显微镜、扫描电镜、能谱仪等分析手段研究了激光焊接工艺对QAl11-6-6铜合金焊接接头显微组织的影响。结果表明:焊接速度对焊缝的宏观形貌有较大的影响。焊接速度较低时焊缝及热影响区较大,而随着焊接速度的增加,焊缝变窄,但焊缝的熔透性变小。焊接速度为10 m/min时,由于热输入小、冷却速率大,焊缝区晶粒较细,其尺寸为5μm左右,且基本无氧化夹杂等缺陷;焊缝区的相组成主要为α相、β′相、K相,未发现γ2相的存在,因而可避免焊接接头出现脆性断裂。

The effect of laser welding technology on the microstructure of QAl11-6-6 copper alloy welded joint was studied by OM, SEM, EDS. The results show that welding speed has a great influence on the macro morphology of the weld. When the welding speed is low, the range of weld and heat-affected zone is large. With the increase of welding speed, the weld zone becomes narrow and the weld penetration becomes small. When the welding speed is 10 m/min, due to the small heat input and large cooling rate, the grains of weld zone is fine, the size is about 5μm and there is almost no oxide inclusions. The microstructure of weld zone is mainly composed of α phase, β phase and K phase, and no γ2 phase is found, which can avoid the brittle fracture of welded joint.