超音速火焰喷涂NiCoCrAlY粒子沉积行为的数值模拟研究  

Numerical Simulation Study of Particle Deposition Behavior of NiCoCrAIY by High Velocity Oxy-Fuel Spraying

作　　者：崔彦郁 刘思思[1,2] 杨正航 涂晓萱 刘金刚 CUI Yanyu;LIU Sisil;YANG Zhenghang;TU Xiaoxuan;LIU Jingang(School of Mechanical Engineering and Mechanics,Xiangtan University,Hunan Xiangtan 411105,China;Hunan Shaofeng Institute for Applied Mathematics,Hunan Xiangtan 411105,China)

机构地区：[1]湘潭大学机械工程与力学学院,湖南湘潭411105 [2]湖南韶峰应用数学研究院,湖南湘潭411105

出　　处：《摩擦学学报(中英文)》2025年第1期3-12,共10页Tribology

基　　金：国家自然科学基金项目(52175191);装备预研教育部联合基金项目(8091B030123);湖南省青年科技人才项目(2022RC1133);湖南省自然科学基金项目(2023JJ50238);湖南省青年科技人才项目(2022RC1133);湖南省制造业关键产品“揭榜挂帅”项目(2023GXGG001,2023GXGG018)资助。

摘　　要：面对航空部件高效高性能需求,表面涂层技术快速发展.宏观涂层沉积实质是微观颗粒冲击堆垛,当前关于喷涂粒子的沉积行为研究大多集中在冷喷涂单颗粒变形,忽略了超音速火焰喷涂这类复杂热流固耦合过程中多颗粒的沉积变化.通过耦合欧拉-拉格朗日法和Johnson-Cook材料方程建立随机多颗粒冲击模型,研究了超音速火焰喷涂过程中主要沉积参数(颗粒冲击速度、颗粒冲击温度、基体预热温度和表面摩擦系数)对NiCoCrAlY涂层孔隙率和GH4169基体残余压应力的独立影响.基于沉积前喷涂颗粒系统内的速度层级,探索了颗粒对撞速度差值和撞击点数量差异导致的不同碰撞程度对涂层质量的作用.结果表明:沉积系统动能绝大部分转为了颗粒变形与升温所需的塑性耗散能和内能;随着颗粒冲击速度和温度的增加,粒子的扁平化变形更充分,涂层孔隙率呈逐渐降低的趋势;为了形成连续的层状结构,颗粒冲击温度不宜过高(不大于1 300 K),以保证颗粒有效适度的变形;改变基体预热温度与表面摩擦系数对孔隙率的影响甚微;基体残余压应力受颗粒冲击速度影响最大,速度减小使冲击影响深度减小的同时平均应力值也减小;沉积前颗粒系统内速度层级较少时(一级或二级),对撞速度差值越大,碰撞程度越大越有利于颗粒间形成共融,涂层孔隙率越低;速度层级逐渐增多,撞击点数量逐渐增大,孔隙率先减后增,过度碰撞使颗粒散射.最后,建议沉积前颗粒筛分以获得颗粒系统中等速度层级,此时适当程度的颗粒碰撞有助于提高涂层致密度.In the face of the strong demand for high efficiency and high performance of aviation components,surface coating technology is developing rapidly.The coating deposition at the macro level is essentially the particle impact stacking at the micro level.At present,most of the research on the deposition behavior of sprayed particles focuses on the deformation of single particles in cold spraying,ignoring the deposition changes of multiple particles in complex thermal-fluid-solid coupling process such as high velocity oxy-fuel spraying.In this work,a random multi-particle impact model had been established by Coupled Eulerian Lagrangian method and Johnson-Cook material equation,and the independent effects of the main deposition parameters(the impact velocity of particle,the impact temperature of particle,substrate preheating temperature,surface frictional coefficient)on the porosity of NiCoCrAIY coating and the residual compressive stress of GH4169 substrate during high velocity oxy-fuel spraying were studied.Based on the velocity level within the spraying particle system before deposition,the effects of different collision degrees caused by the difference of particle collision velocity and the number of collision points on the coating quality were carried out.It was found out that most of the kinetic energy of the deposition system was converted into plastic dissipation energy and internal energy for particle deformation and heating.With the increasement of particle impact velocity and particle impact temperature,the flattening deformation of the particles had become more sufficient,and the porosity of the coating tended to gradually decrease.In order to form a continuous layered microstructure,the impact temperature of the particles should not be too high(not more than 1300 K)to ensure the effective and moderate deformation of the particles.Changing the substrate preheating temperature and frictional coefficient of the substrate played little effect on the porosity of the coating.The residual compressive stress of th

关 键 词：数值模拟 孔隙率 残余应力 颗粒碰撞 

分 类 号：TH117.1[机械工程—机械设计及理论]