Chemical-assisted polishing is an effective method for improving the polishing efficiency and surface quality of photoelectric wafers during magnetorheological polishing (MRP). However, a single chemical assisted is increasingly difficult to meet the application requirements of the new generation of optoelectronic chips. In order to achieve efficient and non-destructive ultra-precision polishing, a new polishing method named photocatalysis-electro Fenton composite magnetorheological polishing (PEMRP) has been proposed. Then, fixed-point centering polishing experiments were conducted on silicon wafers to study the mechanism of PEMRP. The results demonstrate that single chemical-assisted magnetorheological polishing (CMRP) results in reduced magnetorheological properties and poor surface quality due to the oxidation of magnetic particles and the adhesion of iron oxides on the surface of silicon wafers. In contrast, PEMRP can inhibit the adhesion of iron oxides and promote the separation of electron-hole pairs on the surface of photocatalysts, thereby enhancing the conversion rate of hydrogen peroxide to hydroxyl radicals. The photocatalytic system can also promote the hydrogen peroxide generation rate of the electric Fenton cathode and ensure the continuous progress of the chemical reaction. After 30 minutes of PEMRP, the surface roughness of the silicon wafer decreased from 600 nm to 2.54 nm, which is a 44.2% decrease compared to magnetorheological polishing. Additionally, the material removal rate increased by 70.8% to 13.3 mg/h. Finally, a PEMRP model is proposed, which provides a good research foundation for multi-field effect composite magnetorheological polishing.

Magnetorheological polishing; Photocatalysis; Electric Fenton reaction; Rheological properties; Synergies