AZ91D镁合金真空电子束深熔焊接熔池气泡流数值模拟  

Simulation of bubble flow in molten pool of vacuum electron beam welding on AZ91D magnesium alloy

作　　者：叶宏[1] 罗怡[1] 余耀华[2] 

机构地区：[1]重庆理工大学材料科学与工程学院,重庆400050 [2]四川大西洋焊接材料股份有限公司,643010

出　　处：《焊接学报》2012年第7期73-76,117,共4页Transactions of The China Welding Institution

基　　金：重庆市教委科学技术研究资助项目(KJ100826)

摘　　要：针对AZ91D镁合金焊接熔池的气—液两相流系统,在质量守恒和动量守恒的基础上,建立了真空电子束焊接熔池二维气泡流数学模型,模拟计算了熔池中的气相分布、气泡流流动现象,分析了对空腔型缺陷形成、分布的实际影响.结果表明,完全穿透型焊缝熔池中的气体逸出可能性大大高于非穿透型焊缝,使其出现空腔型缺陷的几率在一定程度上低于非穿透型焊缝.典型空腔型缺陷的形成过程与电子束焊特有的深熔焊缝熔池中气泡流的流型及其流动特征有密切关系.较高的液相对流速度更有利于熔池中气体的逸出,从而使焊缝最终的含气率较低.The two-dimensional model of bubble flow in molten pool of vacuum electron beam welding on AZ91D magnesium alloy is developed based on the conservation of mass and momentum and the system of gas-liquid two-phase-flow.The gas distribution and velocity distribution of bubble flow in molten pool are simulated to analyze the formation and distribution of cavity defects.The results show that the possibility of gas escape in fully penetrated molten pool is much greater than non-penetrated molten pool.This also indicates that the probability of cavity defects in fully penetrated weld is lower than non-penetrated weld to some extent.The formation of cavity defects is closely related to the flow pattern and flow characteristics of the bubble flow in deep penetration molten pool.Higher liquid flow rate is more conductive to the escape of gas in molten metal,so that the final porosity in that weld is low.

关 键 词：数值模拟 真空电子束焊 气泡流 空腔型缺陷 

分 类 号：TG442[金属学及工艺—焊接]