磁流变抛光表面粗糙度建模与仿真

Modeling and Simulation of Surface Roughness in Magnetorheological Finishing

为研究磁流变抛光表面粗糙度与工艺参数之间的关系,本文建立数学模型并进行了求解验证。通过分析磁流变抛光技术的原理以及磁流变抛光过程中的材料去除机理,结合Preston方程建立磁流变抛光力学模型。分析工件表面受到的正压力,依据磁流变抛光机理对氧化锆陶瓷工件理论模型的流体动压力和磁场产生的磁化压力进行求解分析,具体化磁流变抛光的力学模型,解得正压力。对磁流变抛光的表面粗糙度进行建模,依据单颗磨料的材料去除作用模型建立磁流变抛光的表面粗糙度数学模型,分析抛光过程中影响表面粗糙度的具体因素,并通过MATLAB软件对方程进行仿真求解,得到磁场强度和磨料粒径对表面粗糙度的影响规律。结果表明,表面粗糙度和工件的压入深度存在一阶线性关系;当磨料粒径固定不变时,表面粗糙度随着磁场强度的增大而增大;当磁场强度固定不变时,表面粗糙度值与磨料粒径之间呈现正比关系。通过实验证明了模型和仿真结果的准确性,仿真分析得到的磁场强度与磨料粒径的关系,磁场强度与表面粗糙度之间的关系与实验一致,确定的磁场强度合理范围为0.4T左右,磨料粒径在2.5μm左右。

To study the relationship between the surface roughness and process parameters of magnetorheological polishing(MRF),a mathematical model and the problem is established and solved.In this paper,the principle of MRF technology and the material removal mechanism in the process of MRF polishing are analyzed,and combining with preston equation,the mechanical model of MRF polishing is established,and the positive pressure is solved.The surface roughness mathematical model of MRF polishing is established according to the material removal model of single abrasive,and the mathematical model of MRF polishing is established by MATLAB software.The experimental results show that the model and simulation results are accurate.There is a first-order linear relationship between the surface roughness and the depth of the abrasive pressing into the workpiece.When the abrasive particle size is fixed,the surface roughness increases with the increase of the magnetic field strength.When the magnetic field strength is fixed,the surface roughness value is proportional to the abrasive particle size.The relationship between the magnetic field strength and the abrasive particle size obtained by simulation analysis and the relationship between magnetic field strength and surface roughness are consistent with the experiment.The reasonable range of magnetic field strength determined is about 0.4T and abrasive particle size is about 2.5μm.