Numerical analysis of thermal fluid transport behavior during electron beam welding of 2219 aluminum alloy plate  

2219铝合金板电子束焊接过程热流传输行为的数值分析（英文）

作　　者：Cheng-cai LIU Jing-shan HE 刘成财;何景山(哈尔滨工业大学先进焊接与连接国家重点实验室,哈尔滨150001)

机构地区：[1]State key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China

出　　处：《Transactions of Nonferrous Metals Society of China》2017年第6期1319-1326,共8页中国有色金属学报（英文版）

摘　　要：A two-dimensional mathematical model based on volume-of-fluid method is proposed to investigate the heat transfer,fluidflow and keyhole dynamics during electron beam welding(EBW)on20mm-thick2219aluminum alloy plate.In the model,anadaptive heat source model tracking keyhole depth is employed to simulate the heating process of electron beam.Heat and masstransport of different vortexes induced by surface tension,thermo-capillary force,recoil pressure,hydrostatic pressure and thermalbuoyancy is coupled with keyhole evolution.A series of physical phenomena involving keyhole drilling,collapse,reopening,quasi-stability,backfilling and the coupled thermal field are analyzed systematically.The results indicate that the decreased heat fluxof beam in depth can decelerate the keyholing velocity of recoil pressure and promote the quasi-steady state.Before and close to thisstate,the keyhole collapses and complicates the fluid transport of vortexes.Finally,all simulation results are validated againstexperiments.提出一种基于有限体积法的二维数学模型,以研究20 mm厚2219铝合金板在电子束焊接过程的热传递、流体流动以及匙孔的动力学行为。采用一种能够实时跟踪匙孔深度的自适应热源模型来数值模拟电子束的加热过程。由表面张力、热毛细力、反冲压力、流体静压力以及热浮力等诱导的不同涡旋的热和质量输运作用与匙孔演变相互耦合。详细分析了一系列物理现象,包括电子束焊接过程中的匙孔钻取、塌陷、重新打开、准稳态过程、回填过程以及在此过程中的温度变化。结果表明,深度方向降低的电子束热流能减慢反冲压力的匙孔钻取速度,并促进准稳定状态的出现。在准稳定状态出现之前,匙孔会发生塌陷并加剧涡旋流体输运的复杂性。最后,所有的计算结果与实验结果进行对比,来验证数学模型的可行性。

关 键 词：heat transfer fluid flow keyhole dynamics electron beam welding mass transport VORTEX recoil pressure BACKFILLING 

分 类 号：TG456.3[金属学及工艺—焊接]