激光-GMAW复合热源焊接熔池-小孔行为分析  

Analysis of Weld Pool and Keyhole Behaviors in Laser-GMAW Hybrid Welding

作　　者：张皓庭 武传松[1] 

机构地区：[1]山东大学材料连接技术研究所,济南250061

出　　处：《航空制造技术》2016年第19期45-51,共7页Aeronautical Manufacturing Technology

基　　金：山东省自然科学基金资助项目(ZR2014EEM002)

摘　　要：掌握和深入理解激光-GMAW复合热源焊接过程中的熔池与小孔行为,是实现复合热源焊接工艺参数优化并将其应用于实际工程的前提。综合考虑激光和电弧的热-力作用以及熔滴过渡带入熔池的质量、热量和动量,建立了激光-GMAW复合热源焊接过程的数值分析模型。定量分析了复合热源焊接过程中熔池流体流动与传热过程以及小孔的动态行为。数值分析结果表明,小孔壁面上各种力相互作用和影响,在小孔前/后壁上会周期性地出现微小凸台,小孔孔道处于短暂瞬间闭合与重新张开的瞬时演变状态。熔滴冲击造成的熔池凹陷与小孔周期性合并与分离,加剧了小孔的不稳定性。熔池内形成两个方向相反的涡流,并在电弧下方附近发生交汇。Deep understanding of weld pool and keyhole behaviors in laser-GMAW hybrid welding is a prerequisite to realize process parameters optimization and practical applications in manufacturing. In this study, a mathematical model is developed for analyzing laser-GMAW hybrid welding process through comprehensively considering thermal and pressure actions from laser and arc as well as the mass, heat and momentum delivered into weld pool by transferring droplets. The fluid flow and heat transfer in weld pool and the dynamic behaviors of keyholes are quantitatively analyzed. The numerical results show that the interaction of various forces on keyhole wall makes periodic formation of little lug at the front and rear walls of keyholes, which causes the momentary closing and re-opening of keyhole channel. The impingement from droplets results in a depression at weld pool surface, and this depression merges and separates with the keyhole periodically, which enhances the instability of keyholes. There are two flow loops with reverse directions inside weld pool, and they join at a location right below the arc.

关 键 词：复合热源焊接 激光 GMAW 熔池 小孔 流场 

分 类 号：TG40[金属学及工艺—焊接]