Machining single crystal GaAs and GaN is challenging due to their inherent brittleness and high hardness, making it difficult to achieve high material removal rates (MRR) without compromising surface quality. This study develops novel oxidizing compound slurries that consist of Fenton solution, graphene oxide (GO) and alumina abrasive for use in a chemically enhanced lapping (CEL) process to improve machining efficiency. The Fenton-based slurry significantly improved lapping performance, achieving significantly higher MRR (355 ± 4 μm/h for GaAs; 51 ± 2 μm/h for GaN) and lower surface roughness ( R a = 7.0 nm for GaAs; 2.5 nm for GaN) compared with water and H 2 O 2 -based slurries. These improvements are attributed to hydroxyl radicals ( • OH) generated during Fenton reaction that induce surface oxidation, forming a soft oxide layer. This layer facilitates material removal while mitigating surface damage, including chipping and scratching, by reducing direct mechanical interaction with the abrasives. Adding graphene oxide (GO) as a lubricant further improved surface finish, reducing R a by 12% (6.2 nm) and 43% (1.4 nm) for GaAs and GaN, respectively. For GaAs, GO reduced MRR due to lower abrasive engagement, whereas MRR for GaN remained largely unaffected. Overall, GO-enhanced Fenton-based slurries offer a favorable balance between high removal efficiency and superior surface quality, providing optimized results for both materials. • A novel chemically enhanced lapping process was developed for GaAs and GaN. • Fenton reaction generates • OH, enhancing MRR without compromising R a . • • OH-induced oxidation forms a soft oxide layer for easy removal and surface protection. • Graphene oxide (GO) lubrication significantly improves lapped surface quality • GO-enhanced Fenton slurries balance high removal efficiency with superior surface quality.
Al-Amin et al. (Fri,) studied this question.