Proceedings of the
9th International Conference of Nanomanufacturing (nanoMan2024)
December 1 – 4, 2024, Singapore
Study of the Influence of pH on NiP Ultra-Precision Polishing
State Key Laboratory of Precision Measuring Technology and Instruments, Laboratory of Micro/Nano Manufacturing Technology, (MNMT), Tianjin University, Tianjin, China.
ABSTRACT
Abstract: The nickel-phosphorus (NiP) coating has corrosion resistance, high hardness, wear resistance, and good machinability, which is a widely used surface layer in optical molds. However, cutting marks appear on the NiP coating surfaces after single point diamond turning (SPDT), leading to diffraction and stray light, which affects the quality of workpieces. Based on chemical mechanical polishing (CMP) approach, this article investigates the effect of citric acid, an environment-friendly pH regulator, on the CMP of NiP coating, and then identify the best pH value of the polishing solution on the self-developed polishing device, to effectively remove the cutting marks. The single factor variable experiment is conducted to determine the optimal pH value of the polishing solution. A surface roughness of 0.28 nm in Sa are successfully achieved on the NiP coating, and the influence of pH on the surface roughness is discussed. This work provides a theoretical basis and technical support for the ultra-precision polishing of NiP coating.
Keywords: Nickel-phosphorus coating, Single point diamond turning, Chemical mechanical polishing, Surface roughness.
