真空电子束深熔焊接匙孔前沿蒸发传热分析模型  

An analytical model of heat transfer by evaporation on front keyhole wall in vacuum electron beam welding

作　　者：罗怡[1] 杜长华[1] 许惠斌[1] 杨世科 

机构地区：[1]重庆理工大学材料科学与工程学院,重庆400050 [2]重庆电力建设总公司,重庆400060

出　　处：《焊接学报》2011年第6期65-68,116,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);科技部高新技术资助项目(2008EG115065)

摘　　要：根据真空电子束焊接过程匙孔深熔效应的特点,建立简化的圆柱形匙孔物理模型.考虑到匙孔前沿的强烈蒸发现象,提出一种基于传热学理论的匙孔前沿气固界面传热分析模型.通过模型分析了AZ系列镁合金材料的主要金属元素Mg,Al,Zn和Mn在匙孔前沿的蒸发效应,以及匙孔半径变化对匙孔前沿气固界面处4种金属元素温度变化的影响.结果表明,AZ系列镁合金的真空电子束焊接过程中,Mg和Zn元素是极易发生烧损的金属元素,且镁的蒸发先于锌发生;较小的匙孔半径将使匙孔前沿的温度显著提高,对于元素的蒸发效应具有较大的影响.A simple cylindrical physical model of keyhole was developed according to the characteristic of deep-penetration effect in vacuum electron beam welding.An analysis model of heat transfer on the interface of vapor phase and front keyhole wall was proposed to the temperature calculation on the basis of heat transfer theory.The evaporation of the primary elements,which are Mg,Al,Zn and Mn in AZ series magnesium alloy,can be analyzed by the model,as well as the influence of keyhole radius varying to the temperature on the vapor-solid interface of the front keyhole wall.The calculation result shows that Mg and Zn are vulnerable to vaporize loss during the vacuum electron beam welding on AZ series magnesium alloy,and the evaporation of Mg occurs earlier than the Zn.The smaller keyhole radius will significantly increase the temperature of the front keyhole wall,which has a great influence on the evaporation effect of the elements.

关 键 词：真空电子束焊接 匙孔效应 蒸发传热 匙孔尺寸 镁合金 

分 类 号：TG402[金属学及工艺—焊接]