【摘要】 【目的】旨在解决传统钨极惰性气体（Tunsten inert gas, TIG）熔覆工艺存在的预置粉末适应性差、试验数据匮乏的问题。【方法】文中设计并制造了管状同轴和环状同轴送粉TIG焊枪，建立三维数值模型对比电弧形态、流场及粉末利用率，随后开展工艺试验，以焊接热输入、送粉量和SiC浓度为变量进行熔覆层制备与评价。【结果】研究结果表明，数值模拟中环状同轴送粉可保持电弧“钟罩”完整，无环状涡流，粉末利用率显著高于管状结构；工艺试验表明，管状送粉熔覆层在熄弧处出现凹坑，且焊缝不平直、熔宽不均匀，而环状送粉熔覆层表面平整、几何均匀，且熔覆效率提高。【结论】环状同轴送粉TIG熔覆在电弧稳定性、粉末利用率和成形质量方面均优于管状结构，更适合高效表面修复工程应用。更多还原

【Abstract】 [Objective] The aim is to solve problem of poor adaptability of pre-placed powder and lack of experimental data in conventional tunsten inert gas(TIG) cladding. [Methods] This paper designed and fabricated tubular and annular coaxial powder-feeding TIG guns. A three-dimensional numerical model was established to compare arc morphology, flow field and powder utilization rate, followed by process experiments in which welding heat input, powder-feeding rate and SiC concentration were varied to produce and evaluate cladding layers.[Results] The results showed that annular coaxial powder-feeding maintained a complete “bell-shaped” arc, eliminated annular vortices and achieved significantly higher powder utilization rate than tubular structure. Process trials revealed that tubular powder-feeding cladding layers had pits at arc extinguishing position, non-straight welds and uneven weld width, whereas the annular powder-feeding cladding layers presented a smooth surface, uniform geometry and higher cladding efficiency. [Conclusion] Annular coaxial powder-feeding TIG cladding is better than tubular configuration in arc stability, powder utilization rate and forming quality, making it more suitable for high-efficiency surface-repair applications.更多还原