摘要
塑性磨料气射流加工(PAJM)是一种先进的减材加工技术,是采用热固性塑性磨料代替传统硬磨料而发展的新型技术,该技术可有效去除表面涂层,且不损伤基材。基材无损主要是通过控制塑性磨料对基材的冲蚀应力,使得塑性磨料的冲蚀应力小于基材纤维的极限强度或纤维与树脂的结合强度。本研究采用有限元仿真和试验相结合的方法,对颗粒速度进行理论分析、计算流体动力学仿真模拟和试验研究,研究不同气体压力下的颗粒速度,计算结果与试验数据吻合较好。结果表明,随着磨料颗粒离开喷嘴,在距离喷嘴出口6.2 dN内(dN为喷嘴内径),颗粒速度增加;相反,距离喷嘴出口6.2 dN外,颗粒速度逐渐减小。当磨料粒径由20~30目变为40~50目时,最大颗粒速度由164.365 m/s增加到228.402 m/s。随着磨料粒径的减小,颗粒速度增加,且发散角增加。相比而言,数值模型能更好的预测塑性磨料的颗粒速度和分布。该研究突出了控制颗粒粒径和支座距离对射流场颗粒速度和发散角的影响。为控制颗粒对基材的冲蚀应力,避免基材损伤提供理论参考。
Plastic abrasive jet machining(PAJM)is an advanced material-reduced processing technology.It is a new technology developed by using thermosetting plastic abrasives instead of traditional hard abrasives,which could effectively remove surface coatings without damaging the substrate.The lossless substrate is obtained by controlling the erosion stress of the plastic abrasive on the substrate,the erosion stress of the plastic abrasives should be less than the ultimate strength of the substrate fibers or the bonding strength between the fibers and the resin.Theoretical analysis,computational fluid dynamics simulation and experiments of particle velocities were carried out using a combination of finite element simulation and experiments.The particle velocities under different gas pressures were investigated,and the calculated results were in good agreement with the experimental data.The results show that as the abrasive particles leave the nozzle,the particle velocity increases within 6.2 d N(d N is the inner diameter of the nozzle)from the nozzle outlet;on the contrary,the particle velocity gradually decreases outside 6.2 d N from the nozzle outlet.When the abrasive particle size changes from 20-30 mesh to 40-50 mesh,the maximum particle velocity increases from 164.365 m/s to 228.402 m/s.As the abrasive particle size decreases,the particle velocity increases and the angle of divergence increases.In comparison,the numerical modeling provides a better prediction of particle velocity and distribution of plastic abrasives.This study highlights the effects of the control of the particle size and standoff distance on the particle velocity and angle of divergence in the jet field.It provides a theoretical reference for controlling the erosion stress of particles on the substrate and avoiding substrate damage.
作者
易茜
赵洋洋
王燕萍
YI Qian;ZHAO Yangyang;WANG Yanping(College of Mechanical and Electrical Engineering,Southeast University Chengxian College,Nanjing 210088,China;Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;School of Naval Architecture&Intelligent Manufacturing,Jiangsu Maritime Institute,Nanjing 211170,China)
出处
《塑料工业》
CAS
CSCD
北大核心
2024年第5期169-174,共6页
China Plastics Industry
基金
江苏省精密与微细制造技术重点实验室开放基金(JSKL2223K10)。
关键词
气射流加工
塑性磨料
颗粒速度
有限元仿真
数值模拟
Air Jet Machining
Plastic Abrasive
Particle Velocity
Finite Element Simulation
Numerical Simulation
