基于多场耦合仿真的脉冲电化学加工温度域的研究

发布时间：2018-05-04 18:20

本文选题：脉冲电化学加工 + 仿真　；参考：《合肥工业大学》2017年硕士论文

【摘要】：脉冲电化学加工能够显著改善电化学加工间隙过程的理、化特性,提高加工精度和表面质量。但是,脉冲电化学加工也具有直流电化学加工的局限性和缺点,为解决其存在的不足,需要对加工过程进行仿真模拟。在电化学加工中,加工区域的温度分布会影响电导率和电流效率,从而影响加工精度。因此,本课题主要研究脉冲电化学加工过程中温度场的分布,通过多场耦合仿真,实现阳极型面的最终预测,减少试验次数,缩短阴极修整时间,节约加工成本。基于多离子传输与反应模型进行电化学加工仿真模拟,真实地反映出离子的电迁移、扩散和对流现象以及并发的电极反应(如阳极金属溶解和氧气析出)。通过仿真分析,拟合出电流效率—电流密度的函数表达式,并探明温度对电流效率、电导率和电极极化的影响规律。基于电压模型建立脉冲电化学加工的多场耦合仿真模型,研究单个脉冲周期内加工间隙的温度变化规律,探究各工艺参数对加工间隙温度分布的影响关系。同时,在模型中引入电流效率—温度和电导率—温度函数表达式,利用COMSOL with MATLAB软件对脉冲电化学加工的全过程进行动态仿真。通过平板电极电化学加工实验和叶片电化学加工实验,验证了多离子传输模型对电流效率仿真计算的可靠性,而基于电压模型的叶片电化学加工动态仿真存在误差,需要进一步优化。
[Abstract]:Pulse electrochemical machining can significantly improve the mechanical and chemical characteristics of the electrochemical machining gap process and improve the machining accuracy and surface quality. However, pulse electrochemical machining also has the limitations and shortcomings of DC electrochemistry machining. In order to solve its shortcomings, it is necessary to simulate the machining process. In electrochemical machining, the temperature distribution in the processing area will affect the electrical conductivity and current efficiency, thus affecting the machining accuracy. Therefore, the distribution of temperature field in pulse electrochemical machining is mainly studied in this paper. Through multi-field coupling simulation, the final prediction of anode profile can be realized, the number of experiments will be reduced, the dressing time of cathode will be shortened, and the processing cost will be saved. The simulation of electrochemical machining based on multi-ion transport and reaction model can truly reflect the electromigration diffusion and convection phenomena of ions as well as the concurrent electrode reactions such as anodic metal dissolution and oxygen precipitation. The functional expression of current efficiency and current density is fitted by simulation analysis, and the effect of temperature on current efficiency, conductivity and electrode polarization is investigated. Based on the voltage model, a multi-field coupling simulation model of pulse electrochemical machining was established to study the temperature variation of machining gap in a single pulse cycle, and to explore the relationship between the process parameters and the temperature distribution of machining gap. At the same time, the expressions of current efficiency temperature and conductivity temperature function are introduced into the model, and the dynamic simulation of the whole process of pulse electrochemical machining is carried out by using COMSOL with MATLAB software. The reliability of the multi-ion transfer model for the simulation of current efficiency is verified by the experiments of plate electrode electrochemical machining and blade electrochemical machining. However, there are errors in the dynamic simulation of blade electrochemical machining based on voltage model. Further optimization is needed.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG662

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