中国激光, 2020, 47 (11): 1102006, 网络出版: 2020-11-09
开放环境下钛合金激光熔覆的局部气氛保护模型 下载: 909次
Local Shielding Gas Model for Laser Cladding of Titanium Alloy in Open Environment
激光技术 激光熔覆 钛合金 开放环境 局部保护气氛 响应面法 光内送粉 laser technique laser cladding titanium alloy open environment local shielding gas flow response surface method inside-beam powder feeding
摘要
针对开放环境下钛合金在激光熔覆过程中易被氧化的问题,提出了一种局部气氛保护模型。采用Fluent软件分析了不同保护气体流量下局部保护喷嘴可提供的有效保护气氛范围,并通过三次多项式拟合建立了气流有效保护长度的数学模型;然后利用响应面法建立了包括保护气体流量在内的工艺参数与熔覆过程中待保护高温区域长度之间的二次回归模型;对两个模型进行联立分析,最终建立了开放环境下钛合金激光熔覆的局部气氛保护模型。验证试验所得单道熔覆层形貌良好,表面呈银白色的金属光泽,说明熔覆过程中熔池及其周围高温区域得到了有效保护。所建局部气氛保护模型可用于指导开放环境下钛合金激光熔覆过程中保护气体流量的选用。
Abstract
A local shielding gas model is proposed herein to address the easy oxidation of titanium alloys during the laser cladding process in an open environment. The effective protection ranges provided by the local shielding gas nozzle under different gas flow rates are analyzed with the Fluent software, and the mathematical model of the effective protective length of the airflow is established through the third-order polynomial fitting. Then, the response surface method is used to establish the quadratic regression model between the process parameters, including the shielding gas flow and the length of the high-temperature region to be protected during the laser cladding. The local shielding gas model for titanium-alloy laser cladding in an open environment is established through the analysis of the above two models. The single-pass cladding layer obtained through the verification test exhibits a good morphology and a bright-silver metallic luster on the surface, indicating that the molten pool and its surrounding high-temperature area are effectively protected during the cladding process. The local shielding gas model established can be used to guide the selection of the shielding gas flow rate required in the laser cladding process in an open environment.
龚燕琪, 傅戈雁, 石拓, 李刚, 张津超, 余司琪. 开放环境下钛合金激光熔覆的局部气氛保护模型[J]. 中国激光, 2020, 47(11): 1102006. Gong Yanqi, Fu Geyan, Shi Tuo, Li Gang, Zhang Jinchao, Yu Siqi. Local Shielding Gas Model for Laser Cladding of Titanium Alloy in Open Environment[J]. Chinese Journal of Lasers, 2020, 47(11): 1102006.