激光束时/空域形态对定向能量沉积316L不锈钢组织的影响  

Effects of the Temporal and Spatial Profile of Laser Beam on the Microstructure of 316LStainless Steel in Laser-Based Energy Deposition

作　　者：郑小强 吴家柱[1] 曹阳[1] 张大斌[1] 孙杰 Zheng Xiaoqiang;Wu Jiazhu;Cao Yang;Zhang Dabin;Sun Jie(School of Mechanical Engineering,Guizhou University,Guiyang550025,Guizhou,China)

机构地区：[1]贵州大学机械工程学院,贵州贵阳550025

出　　处：《应用激光》2024年第3期1-12,共12页Applied Laser

摘　　要：以激光束的时/空域形态为调控对象,采用激光定向能量沉积方式制备了不同时/空域下的单道多层316L不锈钢试样,分析各参数对试样的显微硬度、微观组织特征的影响。正交试验结果表明:晶粒等效直径、柱状晶长宽比、柱状/等轴晶数量比均随着频率和占空比的增大,先快速减小后略微增大。相比连续光束,中频(40/60 Hz)中占空比(0.6/0.8)下的晶粒等效直径、柱状晶长宽比、柱状/等轴晶数量比分别减小19.4%、3.4%、13.3%。空域形态下,相比高斯光束,超高斯光束下晶粒等效直径减小0.14μm,而柱状晶长宽比、柱状/等轴晶数量比分别增大0.06、0.45。各因素对等效直径、柱状晶长宽比、柱状/等轴晶数量比、显微硬度的影响程度分别为:占空比>频率>形态指数、频率>占空比>形态指数、频率>形态指数>占空比、形态指数>频率>占空比。This paper investigates the temporal and spatial profiles of laser beams as control parameters for the preparation of single-track multi-layer 316Lstainless steel specimens using laser-based directed energy deposition.The effects of parameters on the microhardness and microstructure characteristics of the specimens were analyzed.The orthogonal experiments results show that key evaluation indicators,including grain equivalent diameter,aspect ratio of columnar grains,and quantitative ratio of columnar to equiaxed grains,initially decrease sharply and then exhibit slight increases with rising frequency and duty cycle of pulsed wave lasers.Comparing with the continuous beam,the grain equivalent diameter,aspect of columnar grains,quantify ratio of columnar/equiaxed grain under the medium frequency(40/60Hz)and medium duty cycle(0.6/0.8)are decreased by 19.4%,3.4%,13.3%,respectively.As for the spatial profile,compared with the Gaussian profile beam,the grain equivalent diameter under the super-Gaussian beam decreased by 0.14,while the aspect of columnar grains,quantify ratio of columnar/equiaxed grain increase by 0.06and 0.45,respectively.The effect degree of each factor on equivalent diameter,aspect of columnar grains,quantify ratio of columnar/equiaxed grain and microhardness are as follows:duty cycle>frequency>spatial profile index,frequency>duty cycle>spatial profile index,frequency>spatial profile index>duty cycle,spatial profile index>frequency>duty cycle.

关 键 词：激光定向能量沉积 316L不锈钢 时/空域形态 微观组织 

分 类 号：TG142[一般工业技术—材料科学与工程]