激光诱导增强电弧等离子体的放电状态研究  

Discharge State of Laser Induced and Enhanced Arc Plasma

作　　者：陈明华[1] 李陈宾[1] 刘黎明[1] 

机构地区：[1]大连理工大学材料科学与工程学院辽宁省先进连接技术重点实验室,大连116024

出　　处：《高电压技术》2013年第7期1661-1667,共7页High Voltage Engineering

基　　金：长江学者和创新团队发展计划(IRT1008);国家杰出青年科学基金(51025520)~~

摘　　要：为了研究激光诱导增强电弧复合焊接过程中复合等离子体的放电状态,采用高速摄影结合光谱诊断的方法,对复合堆焊镁合金的熔深状态、等离子体行为和光辐射特性进行了对比分析。结果表明:激光和电弧有3种复合方式,即激光未穿过电弧时电弧根部与激光"匙孔"分离、激光穿过电弧等离子体时电弧根部与"匙孔"分离、电弧根部处于"匙孔"处。当电弧根部作用于激光"匙孔"处时,"匙孔"等离子体与电弧等离子体连接并形成复合等离子体。复合等离子体在"匙孔"内部分具有较高的电导率(1.2×104 S/m)并接近局域热力学平衡状态,这导致激光诱导增强作用下的电弧等离子体在"匙孔"内部具有极高的电流密度(可达到103 A/cm2)和能量利用效率。By using the high speed observation and spectral diagnosis,we compared and analyzed the welding penetration depth,plasma behavior,and plasma spectral feature of magnesium alloy during laser-arc hybrid welding,for understanding the characteristics of arc plasma in the welding process.Results show that there are three kinds of laser-arc combination styles,i.e.arc root separating from laser keyhole when laser beam does not pass through the arc plasma,arc root separating from laser keyhole when laser beam passes through the arc plasma,and the root of arc plasma right on the laser keyhole.When arc plasma roots the laser keyhole,it connects with the keyhole plasma,and a hybrid discharge happens.The keyhole part of the hybrid plasma possesses extreme electric conductivity as high as 1.2×104 S/m and approaches thermal equilibrium state,resulting in the fact that the laser induced and enhanced arc plasma has high electric current density（approximately 103 A/cm2） and energy utilization.

关 键 词：电弧等离子体 激光 匙孔 复合放电 电导率 热力学平衡 

分 类 号：O53[理学—等离子体物理]