摘要
目的建立一种计算曲面工件激光光斑面积变化的数学模型,研究光斑面积在多大范围内变化对熔覆质量的影响最小。方法采用高斯曲率的倒数作为曲率球的半径,利用曲率球代替NURBS曲面微小单元,通过圆柱体与球体相贯的数学分析方法求取截交面积,进而推导出NURBS曲面光斑面积的数学模型,采用CATIA软件作对比,进行验证。结果该数学模型得出的结果与CATIA计算的结果相对误差不超过0.2%,满足工程应用。对模型中影响光斑面积大小的三个因素(离焦量、光束姿态、曲率)进行分析表明,影响光斑面积大小的最主要因素是光束姿态。在此基础上,以Q235为母材,KF310粉末为熔覆材料,调整光束姿态分别以0?、10?、20?、30?、40?为入射角进行激光熔覆,测试和分析得出,在0?、10?、20?时,单道熔覆层宽度随空间夹角及光斑面积的增大而增大,熔覆高度随光斑面积增大而减小,熔覆层与基体之间存在亮白色界面,这是凝固初期界面处生长出的平面晶,说明形成了冶金结合。而30?、40?时的单道熔覆层宽度变化不明显,在熔覆道边缘出现粘粉现象,冶合质量不高。结论光斑面积变化在增加8%的范围内可以保证激光熔覆沉积层的质量,通过该算法的应用可以满足激光再制造快速响应的要求。
The work aims to establish a mathematical model to calculate the change of facula area on curved surface part and study the change range of facula area causing the least effect on the quality of the cladding.The inverse of the Gauss curvature was used as the radius of the curvature sphere and the curvature sphere was used to replace the microelement of the NURBS surface.The cross sectional area was calculated through the mathematical analysis method of the intersection of the cylinder and the sphere so as to derive the mathematical model for the area of the NURBS surface.Through the comparison,the relative error between the result of the mathematical model and the result of CATIA calculation was less than 0.2%and in conformity with the engineering application.Then,three factors(defocusing distance,laser beam attitude and curvature)in the model influencing the size of light spot area were analyzed.Laser beam attitude was the main factor that influences the size of light spot area.On this basis,KF310 alloy powder was deposited on Q235 steel.The beam angle was adjusted for 0 degree,10 degree,20 degree,30 degree and 40 degree angle respectively to test and analyze the microstructure,width and height of the cladding layer.It was concluded that,at 0 degree,10 degree and 5 degree,the width of the single-channel cladding layer increased with the space angle and facula area;while the cladding height decreased with the increase of facula area.There was a bright white interface between the cladding layer and substrate.This was the plane crystal generated at the interface of the initial solidification.It meant that metallurgical bonding was formed;while,at 30 degree and 40 degree,the width of the single-channel classing layer did not change apparently.There was powder stuck to the surface of the cladding layer edge.The metallurgical quality was poor.The light spot area within 8%increase can ensure the quality of laser cladding deposition layer.The application of this algorithm can meet the requirements of rapid response of laser remanufacturing.
作者
崔权维
孙文磊
黄勇
CUI Quan-wei;SUN Wen-lei;HUANG Yong(School of Mechanical Engineering,Xinjiang University,Urumqi 830047,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2018年第11期225-232,共8页
Surface Technology
基金
新疆维吾尔自治区高技术研究发展项目(201513102)~~
关键词
激光熔覆
曲面
光斑面积
光束姿态
熔覆质量
数学模型
曲率球
laser cladding
curved surface
facula area
laser beam attitude
cladding quality
mathematical model
curvature sphere