| YAN Qiu-sheng,LIANG Zhi-bin,PAN Ji-sheng.#$NP Modeling Optimization and Uniformity of Cluster Magnetorheological Polishing via Magnetic Trajectory Intensity in Machining Surface[J],51(12):243-254 |
| #$NP Modeling Optimization and Uniformity of Cluster Magnetorheological Polishing via Magnetic Trajectory Intensity in Machining Surface |
| |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2022.12.025 |
| KeyWord:magnetorheological polishing numerical analysis magnetic trajectory roughness evenness |
| Author | Institution |
| YAN Qiu-sheng |
School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou , China |
| LIANG Zhi-bin |
School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou , China |
| PAN Ji-sheng |
School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou , China |
|
| Hits: |
| Download times: |
| Abstract: |
| Cluster magnetorheological polishing is an efficient planar processing method, which can obtain nano-scale ultra-smooth surface roughness in the polishing process of photovoltaic wafers. The movement mode of the workpiece and the distribution characteristics of the spatial magnetic field have an important effect on the surface uniformity after polishing. The work aims to explore the effects of motion process parameters and spatial magnetic field distribution characteristics on the unevenness of roughness after processing in cluster magnetorheological polishing, and optimize the process parameters to improve the uniformity of surface roughness after processing. A numerical model of the magnetic trajectory intensity including the effective processing trajectory and magnetic trajectory features was proposed. On the basis of the numerical model, the effects of the three motion parameters, namely the rotational speed ratio, the eccentric distance and the reciprocating oscillation, on the two characteristics of the effective processing trajectory and the magnetic trajectory at different positions of the workpiece were analyzed and the speed ratio values in different motion modes were optimized by the model. The polishing experiments of silicon wafers were carried out on a cluster magnetorheological polishing device, and the surface roughness and surface morphology of multiple positions after processing were detected by a white light interferometer, and the roughness distribution was observed. Numerical analysis results showed that the irrational speed ratio could avoid the periodic fluctuation characteristics of different circumferential positions, and choosing the appropriate speed ratio could reduce the difference in the length of the trajectory at different radial positions and improve the uniformity of the trajectory characteristics. Under the condition of irrational speed ratio, changing the eccentricity of the workpiece and increasing the reciprocating swing increased the coverage of the effective processing trajectory, but increased the duty cycle, which resulted in a decrease in the length of the trajectory and a decrease in processing efficiency. Changing the motion pattern of the eccentricity could change the distribution of the magnetic field frequency on the trajectory. Under the condition of the eccentricity 115 mm, the average magnetic field difference between different radial positions of the workpiece was reduced to 0.019 T. The experimental results showed that the variation coefficient of the processed surface roughness under the optimized process parameters was reduced by an average of 37% compared with the control group. The unevenness after polishing in the control group was consistent with the radial distribution law of the magnetic trajectory intensity in the numerical calculation results. At a small speed ratio, the center was smooth and the edge was rough, and at a large speed ratio, the edge was smooth and the center was rough. Under the optimized process conditions of eccentricity of 115 mm and rotational speed ratio of 223∶60, the roughness variation coefficient of the polished silicon wafer was at least 0.309, and the average roughness was Sa 4.19 nm. By comparing the experimental results with the numerical simulation results, the numerical model of the magnetictrajectory intensity can effectively optimize the process parameters of the cluster magnetorheological polishing, which is conducive to the matching of the processing trajectory and the magnetic trajectory characteristics, and improves the unevenness of the workpiece after polishing. The method can further provide guidance for the optimal design of the magnetic field generating device and the structure dimension of the motion part of the cluster magnetorheological polishing device. |
| Close |
|
|
|