Chen Ao, Li Bingchen, Chen Xi, Jiang Meng, Zou Shuai, Tao Wang, Lei Zhenglong, Chen Yanbin
National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China.
State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China.
Materials (Basel). 2023 Sep 30;16(19):6511. doi: 10.3390/ma16196511.
Gas protection is a crucial part of quality control in laser welding, especially for titanium alloy, which oxidizes easily at high temperatures. Substantial experiments concerning shielding gas characteristics in the welding process have been implemented. However, the common analysis conducted is simplistic and lacks a theoretical basis. This paper presented an investigation of the shielding gas behaviors based on numerical simulation and a titanium alloy laser welding experiment. The numerical model was established and validated by experiment. Subsequently, the temperature field and gas flow fields were calculated. By combining the two fields, the threshold temperature of gas protection was determined, and the influence of shielding gas parameters on the protection effect was examined. The results revealed that the protection of the high-temperature zone was primarily influenced by the nozzle height, nozzle inner diameter, and nozzle angle, while the plasma suppression effect was mainly correlated with the nozzle inner diameter and gas flow rate. These initial findings provide scientific guidance for the better quality production of laser beam welded components made of not only titanium alloy but also other metallic materials.
气体保护是激光焊接质量控制的关键部分，特别是对于钛合金而言，钛合金在高温下容易氧化。已经开展了大量关于焊接过程中保护气体特性的实验。然而，常见的分析过于简单，缺乏理论依据。本文基于数值模拟和钛合金激光焊接实验，对保护气体行为进行了研究。通过实验建立并验证了数值模型。随后，计算了温度场和气体流场。通过结合这两个场，确定了气体保护的阈值温度，并研究了保护气体参数对保护效果的影响。结果表明，高温区域的保护主要受喷嘴高度、喷嘴内径和喷嘴角度的影响，而等离子体抑制效果主要与喷嘴内径和气体流速相关。这些初步研究结果为更好地高质量生产不仅由钛合金而且由其他金属材料制成的激光束焊接部件提供了科学指导。
