大功率激光焊接熔池特性数值模拟

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1、兰州理工大学硕上论文摘要摘要随着现代技术的发展，激光焊接的功率越来越大，出现了10Kw的FiberLaser焊接新技术，可以焊接lO哪厚的不锈钢板，焊缝宽度仅l舢左右。当激光功率为10Kw，焊速为4—20m／min时形成特有的大长宽比焊接熔池，本文采用数值模拟的方法对此现象进行了研究。首先运用焓一孔隙度方法建立了移动热源作用下激光焊接过程的控制方程组，给出能量方程和动量方程的边界条件，然后在软件PHOENICS3．4中进行二次开发，分别在Ql控制卡和模块GROUND中编制相应的接口程序，模拟了浮力、表面张力、反蒸

2、发力单独作用及联合作用下不锈钢大功率激光焊接的温度场和流场。论文最后分析了反蒸发力与熔池长度之问的关系，并且验证了模型在低碳钢激光焊接时的实用性。通过模拟结果与试验结果的对比发现：在大功率激光高速焊接时喷发的等离子体对熔池内金属的流动产生很大的影响，等离子体的喷发加速了“匙孔’’附近熔池内金属的流动，将热量带向熔池后部，是大功率激光焊接大长宽比熔池现象形成的主要原因。关键词：大功率激光焊接小孔反蒸发力PHOENICs兰州理工大学硕．仁论文AbstmctAbstractIJaserwelding，whichhaSm

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