冷喷涂中粒子形状和速度参数对撞击过程影响的数值模拟  

Numerical simulation of particle shape and velocity effects on impacting process in cold spray

作　　者：王锋[1] 赵明[2] 

机构地区：[1]重庆大学低品位能源利用技术及系统教育部重点实验室,重庆400030 [2]重庆大学动力工程学院,重庆400030

出　　处：《中国科技论文》2015年第22期2657-2661,共5页China Sciencepaper

基　　金：国家自然科学基金资助项目(50906104)

摘　　要：为了解冷喷涂中粒子形状和速度参数对其沉积过程的影响,采用显示有限元算法和任意拉格朗日-欧拉(ALE)网格划分法,研究了冷喷涂圆球和椭球状铝合金颗粒以不同初始速度撞击镁合金基板过程中,粒子和基板的变形行为和温度变化,以及对其反弹性能、基板坑深和最大相对接触面积的影响。结果表明:粒子形状对碰撞过程中粒子和基板的局部变形有较大影响,表现在对称截面的塑性变形和温度分布具有非对称性;椭球粒子沿其长轴方向垂直撞击基板时,截面局部变形比沿其短轴方向撞击基板情况剧烈;提高粒子撞击基板速度后,其反弹动能与其初始动能百分比不断降低,基板坑深增加,粒子和基板间的最大相对接触面积增加;但球形和椭圆形颗粒形状对基板坑深的影响较小。To understand particle shape and velocity effects on impacting process in cold spray,finite element analysis（FEA）and arbitrary Lagrangian-Eulerian（ALE）grid method were adopted to simulate sphericaland ellipsoidalAl alloy particle impacting behavior on Mg alloysubstrate under different initial incident velocities.The deformation behavior and temperature variation of the particle and substrate,particle shape effect on its rebound performance,crater depth on substrate,and maximum relative contact area,were analyzed.Results reveal that particle shape has significant effects on local deformation of the particles and substrate in impacting process,which can be indicated by the non-symmetry distribution of the plastic deformation and temperature on perpendicular cross sections.Local deformation of ellipsoidal particle impacting along its long axis is more severe than that of impacting along its short axis.With the increase of the particle incident velocity,the percentage of particle rebound kinetic energy to its initial kinetic energy decreases,while the depth of crater on substrate and the maximum relative contact area increase.However,there is no obvious change of substrate crater depth in impacting of spherical and ellipsoidal particles.

关 键 词：冷喷涂 碰撞特性 椭球颗粒变形 热固耦合 ALE网格方法 

分 类 号：TG174.4[金属学及工艺—金属表面处理]