基于VOF模型的铝钎焊板钎料流动成形的数值模拟  

Simulation of filler metal ′s flow and shaping during Aluminum brazing process of heat exchanger cruciform joint

作　　者：罗冲 张振林 单际国[1,2] 

机构地区：[1]清华大学机械工程系,北京100084 [2]先进成形制造教育部重点实验室,北京100084

出　　处：《焊接学报》2018年第7期88-92,共5页Transactions of The China Welding Institution

摘　　要：采用VOF多相流模型,应用Fluent软件对炉中钎焊过程中铝钎焊板十字接头的钎角成形进行模拟研究,讨论了钎焊温度、钎缝间隙等因素对钎角成形的影响规律,并进行了试验验证.结果表明,该模型较好的模拟了钎角的形状以及温度对钎角成形的影响规律,从而验证了模型的可靠性.同时发现温度对钎角成形有较大影响,温度较低(590℃)时,钎料润湿性不足,铺展长度较小;温度过高(610℃)时,钎料流失加剧,铺展长度减小,600℃为最佳温度.接头短间隙过小容易导致钎料聚集,长间隙过大会抑制钎缝的毛细作用,均不利于钎料铺展,等间隙更有利于钎角成形.In order to increase efficiency and improve quality of heat exchanger in air condition further,simulations of Aluminum brazing sheet cruciform joint based on VOF 3D model were carried out to research the wetting process of filler metal under different brazing temperature and joint gap.Meanwhile,experiments were conducted.The results show that the model can simulate the flow and shaping of joint approximately and predict the influence rules of temperature on wetting length,which validates this model.Brazing temperature affects the shaping of joint considerably.Compared to 600℃,590℃and 610℃both led to the decrease of wetting length due to insufficient wettability and running off increasingly of filler metal,respectively.Too little gap generated aggregation of filler metal at bottom of joint and too large gap weakened capillary action,both of which went against the wetting of filler metal.So symmetrical gap for the joint is best.

关 键 词：铝钎焊 数值模拟 钎角成形 钎焊温度 钎缝间隙 

分 类 号：TG454[金属学及工艺—焊接]