激光-氩弧焊电弧复合热源表面熔覆工艺及成形特征

Technology and Forming Characteristics of Laser Tungsten Inert Gas Hybrid Heat Source Surface Cladding

为研究激光-氩弧焊(TIG)电弧复合热源表面熔覆工艺对熔覆层成形特征的影响,建立了激光电弧复合热源表面熔覆试验系统,分别采用大光斑半导体激光热源、激光与TIG复合热源在Q235母材上进行了Ni60合金粉末单道熔覆工艺试验,分析了激光功率、TIG电流对熔覆层高宽比、稀释率、浸润角等成形特征的影响.结果表明:随着激光功率或TIG电流的增加,熔覆层的熔宽、稀释率呈增加趋势,熔覆层的高宽比、浸润角减小.在复合热源熔覆过程中,引入电弧可以显著降低熔覆所需激光功率,可在减小激光热冲击作用的同时降低生产成本;引入小电流TIG电弧,可以降低熔覆层边缘的温度梯度,改善熔覆过程中熔覆层的铺展效果.

In order to study the influence of laser tungsten inert gas （TIG） hybrid heat source surface clad- ding on cladding layer forming, an experimental control system of laser-TIG are hybrid heat source surface cladding, with large flare semiconductor laser and hybrid heat sources as heat source respectively, was es- tablished to conduct the single pass surface cladding process experiment of Ni60 alloy powder on base metal Q235. The influence of laser power and TIG arc current on forming characteristics like cladding layer as- pect ratio, dilution ratio, wetting angle, etc. were analyzed. The results show that the cladding layer width and dilution ratio increases, while the aspect ratio and wetting angle decrease as the laser power or TIG current rises. The introduction of TIG arc significantly reduces the laser power required in low-power laser surface cladding, therefore reduces the production cost as the laser thermal shock decreases. The introduction of TIG arc in high-power laser surface cladding, by reducing temperature gradient on the edge of cladding layer, improves the spreading effect of cladding layer with little influence on dilution ratio.