铝合金振镜激光-双脉冲CMT复合增材熔滴过渡特性  

Droplet Transfer Behavior in Oscillated Scanning Laser Hybrid Dual Pulsed CMT Additive Manufacturing of Aluminum Alloy

作　　者：张刚[1,2] 刘忠义 张程 朱明[1] 石玗[1,2] ZHANG Gang;LIU Zhongyi;ZHANG Cheng;ZHU Ming;SHI Yu(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050;Wenzhou Pump and Valve Engineering Research Institute of Lanzhou University of Science and Technology,Wenzhou 325105)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [2]兰州理工大学温州泵阀工程研究院,温州325105

出　　处：《机械工程学报》2025年第2期120-129,共10页Journal of Mechanical Engineering

基　　金：国家自然科学基金(52265050);陇原青年创新创业人才团队(2022LQTD34);中科院“西部之光”青年学者人才计划(21JR7RA202);兰州市青年科技人才创新(2023-QN-90);温州市级科技计划(2023G0157)资助项目。

摘　　要：先进复合热源在焊接过程精细化调控、组织微控及性能优化等方面独具优势,将成为高性能铝合金增材成形的优选热源。针对丝材铝合金增材过程稳定性低、气孔率高、成形精度低等问题,提出一种功率调制振镜激光与双脉冲CMT电弧复合增材制造的新方法。建立复合热源增材制造试验系统,开展增材工艺试验,分析复合热源作用下焊丝熔化、熔滴过渡行为及过程稳定性,并基于光谱和红外成像数据阐释复合热源交叉区等离子体和温度场变化规律,揭示激光等离子体对熔滴过渡行为的影响机制。结果表明,新工艺能够实现对铝合金增材稳定传质及精细化调控;复合热源下熔滴以射滴过渡+短路过渡的混合模式进行,且当平均电流由90 A增至100 A时,熔滴直径和射滴过渡频率分别从1.49 mm增至1.52 mm,从74 Hz增至82 Hz,短路过渡频率保持不变9 Hz;当激光功率由600 W增至1200 W时,熔滴直径和射滴过渡频率分别从1.52 mm增至1.63 mm,从70 Hz减小至64 Hz,短路过渡频率为8 Hz;熔滴过渡变化是光致等离子体增加复合区能量密度和电弧区电流密度以及高速扫描激光动态调控复合热源能场分布的综合作用结果。Advanced hybrid heat source has unique advantages in fine control of welding process,microstructure,and performance,and will become the preferred heat source for additively manufactured high-properties aluminum alloy.Aiming at the issues of low stability,high porosity,and low accuracy in the aluminum alloy AM process,a new power modulated oscillated scanning laser hybrid dual pulsed CMT method was proposed.An experimental setup was established,and the experiments were performed.The wire fusion,droplets transfer and mass transfer stability in AM process were analyzed,and the changes of plasma and the temperature in the laser-arc cross area were studied by using spectral and infrared data.The effect mechanism of the laser plasma on the droplet transfer was revealed.The results show that a stable mass transfer and fine regulation process of aluminum alloys AM can be obtained.Using the hybrid heat source,the droplet transfer is complied with the free combined short-circuit transition.When the average current increases from 90 A to 100 A,the diameter of the droplet increased from 1.49 mm to 1.52 mm and transition frequency increased from 74 Hz to 82 Hz.The short-circuit transition frequency is 9 Hz.As the laser power increases from 600 W to 1200 W,the transfer frequency decreases from 70 Hz to 64 Hz,the short-circuit transition frequency is 8 Hz,and droplet’s diameter increases from 1.52 mm to 1.63 mm.The change in the transition behavior of the melt droplet is the result of the combined effect of laser photo-plasma increasing the energy density in the composite zone and the current density in the arc zone,as well as high-speed scanning galvanometer laser dynamically modulating the energy field distribution of the composite heat source.

关 键 词：铝合金 振镜扫描激光-双脉冲CMT复合 熔滴过渡 温度场 等离子体 

分 类 号：TG444[金属学及工艺—焊接]