Preparation of CIP@Fe 3 O 4 particles and their impact on the fenton reaction processing performance of single-crystal SiC

This study proposes the preparation of CIP@Fe 3 O 4 composite magnetic particles, which maintain excellent magnetic properties while exhibiting superior Fenton reaction performance for the magnetorheological chemical polishing of single-crystal SiC. The CIP@Fe 3 O 4 particles were prepared by coating a nanoscale layer of Fe 3 O 4 onto micron-sized carbonyl iron powder (CIP) using the co-precipitation method. Their Fenton reaction performance and magnetic properties were characterized, and CIP@Fe 3 O 4 was used as a solid-phase catalyst in Fenton reaction-induced etching, frictional wear, and polishing experiments on single-crystal SiC. The prepared CIP@Fe 3 O 4 particles have a saturation magnetization of 184.3 emu/g, representing only an 8.7 % reduction compared to CIP, yet achieved a decolorization rate of 76.2 % for the methyl orange indicator (compared to only 17.2 % with CIP alone). The Fenton reaction using CIP@Fe 3 O 4 resulted in a prominent corrosion layer on the surface of single-crystal SiC, with the oxygen atomic fraction reaching 22.15 %. The study examined material removal from SiC under Fenton reactions with different solid-phase catalysts: CIP, CIP@Fe 3 O 4, and CIP + Fe 3 O 4. Frictional wear results indicated that the maximum scratch cross-sectional removal area on the SiC surface under the Fenton reaction with CIP@Fe 3 O 4 was 474.38 μm 2, representing a 207.3 % increase compared to without the Fenton reaction. Additionally, Si -O compounds were identified in the debris. Polishing experiments showed that the material removal rate (MRR) with the Fenton reaction was 3295 nm/h, an increase of 220.2 % compared to without the Fenton reaction, and the surface roughness was reduced to Ra 0.895 nm, a 73.4 % reduction compared to without the Fenton reaction. This study provides additional evidence for the application of magnetorheological technology and the Fenton reaction in the polishing field of single-crystal SiC.