基于NSGA-Ⅱ算法的宽带激光熔覆工艺参数优化

Optimization of broadband laser cladding process parameters based on NSGA-II algorithm

为了获得17-4PH沉淀硬化不锈钢粉末在宽带激光熔覆过程中的最优工艺参数,本研究将激光功率、预热温度、扫描速度作为可控输入参数,以熔覆层宽高比、饱和度、润湿角作为输出,进行三因素五水平正交试验。通过麦夸特算法构建的响应值非线性数学模型,探究优化变量及其权重排序对熔覆层宏观形貌的影响规律,并采用第二代非支配遗传算法进行寻优,输出具有Pareto最优前沿,确定最优工艺参数。结果表明:优化后的最优工艺参数组合为激光功率1878 W,扫描速度14 mm/s,预热温度200℃,此时获得的熔覆层宽高比32.08,饱和度0.76,润湿角度10.2°。优化后的结果输出平均误差小于5%。

In order to obtain the optimal process parameters for 17-4PH precipitation hardened stainless steel powder in the broadband laser cladding process,this study takes laser power,preheating temperature,and scanning speed as controllable input parameters,and takes the aspect ratio,saturation,and wetting angle of the cladding layer as output.Three factors and five levels orthogonal experiments are conducted.The response value nonlinear mathematical model constructed by the Mcquart algorithm is used to explore the influence of optimization variables and their weight ranking on the macroscopic morphology of the coating.The second generation non dominated genetic algorithm is used for optimization,and the output has the Pareto optimal frontier to determine the optimal process parameters.The results show that the optimal combination of process parameters after optimization is laser power of 1878 W,scanning speed of 14 mm/s,preheating temperature of 200℃.At this time,the width to height ratio of the obtained cladding layer is 32.08,saturation is 0.76,and wetting angle is 10.2°.The average error of the optimized output is less than 5%.