Title: A study of methods for the magnetorheological finishing of glass panels for the inner screen of mobile phones

Authors: Bin Luo; Qiusheng Yan; Jisheng Pan; Jiabin Lu; Zhiqing Hong

Addresses: School of Electromechanical Engineering, Guangdong University of Technology, No.100 Waihuan Xi Road, Panyu District, Guangzhou, China ' School of Electromechanical Engineering, Guangdong University of Technology, No.100 Waihuan Xi Road, Panyu District, Guangzhou, China ' School of Electromechanical Engineering, Guangdong University of Technology, No.100 Waihuan Xi Road, Panyu District, Guangzhou, China ' School of Electromechanical Engineering, Guangdong University of Technology, No.100 Waihuan Xi Road, Panyu District, Guangzhou, China ' Guangdong Nanogrind Technology Co., Ltd., Room A214-2, Nanhai Industrial think Tank City 1, Taoyuan Road, Shishan Town, Nanhai District, Foshan City, China

Abstract: In order to solve the problem that there are many scratches on the glass panels of the inner screen of mobile phones after chemical mechanical polishing (CMP), three different magnetorheological finishing (MRF) methods were investigated to polish the surface: 1) single-point MRF with static magnetic field; 2) cluster MRF with static magnetic fields; and 3) cluster MRF with dynamic magnetic fields, which turned out to be the most suitable one of the three. The rotation of a permanent magnet relative to the polishing disc generates dynamic magnetic fields, which have a positive effect on the polishing process and thus enable an ultra-smooth, scratch-free, high-quality surface on the glass panels required for the inner screen of mobile phones. Single-factor experiments were carried out to further adjust the key process parameters, such as machining time, machining gap, magnetic-pole speed, polishing-disc speed, and workpiece speed. An optimised parameter set of 20 min machining time, 1.0 mm machining gap, 120 r/min magnetic-pole speed, 60 r/min polishing-disc speed, and 400 r/min workpiece speed led to an improvement of the original surface roughness of a glass panel with scratches and pits from Ra 1.15 nm to Ra 0.45 nm, that is tantamount to an ultra-smooth surface.

Keywords: magnetorheological finishing; MRF; single-point MRF; cluster MRF; static magnetic field; dynamic magnetic field; glass panel; mobile phone; surface roughness.

DOI: 10.1504/IJAT.2019.103501

International Journal of Abrasive Technology, 2019 Vol.9 No.3, pp.235 - 255

Received: 15 Mar 2019
Accepted: 05 Aug 2019
Published online: 06 Nov 2019 *

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