高功率CO2激光焊中He-Ar侧吹气体组分研究
Study on Side Assist Blowing Gas with Different Composition in High Power CO2 Laser Welding
刘必轩， 李国华， 蔡 艳， 吴毅雄
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作者单位：（上海交通大学 材料科学与工程学院，上海 200030）
中文关键字：高功率CO2激光焊； 光致等离子体； 氦氩混合气体
英文关键字：high power CO2 laser welding； laser induced plasma； He-Ar mixed gas
中文摘要：在高功率CO2激光深熔焊中，光致等离子体的抑制是保证熔深、稳定焊接过程的关键技术之一。常用的抑制方法是侧吹氦气，而采用氦氩混合气体可降低生产成本，特别是当氦气含量高于50％时。本文采用氦氩比为4∶6的混合气体，对12 mm厚船用E级钢板进行高功率CO2激光焊接，通过工艺参数优化实现了稳定的焊接过程，全熔透焊缝的质量达到船级社标准。采用流体力学方法建立了高功率CO2激光焊光致等离子体的物理数学模型，分析了氦氩混合气体侧吹时的等离子体特性及对激光能量的影响。
英文摘要：Laser induced plasma can affect the process stability and seam quality in high power CO2 laser welding. As the normal suppression method, pure helium is gradually replaced with He-Ar mixed gas for economical efficiency, especially the He content is more than 50%. The qualified E grade steel seam with 12 mm thickness was welded, when He-Ar ratio was 4:6. Plasma characteristics and its interaction with laser beam were investigated through computational fluid dynamics model for high power CO2 laser welding-induced plasma.