Proceedings of the
9th International Conference of Nanomanufacturing (nanoMan2024)
December 1 – 4, 2024, Singapore
Ultra-smooth combined polishing process for nickel-phosphorus alloy components
State Key Laboratory of Mechanical System and Vibration, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
ABSTRACT
As a metal coating material commonly used in optical components, nickel-phosphorus (NiP) alloy has excellent machinability, wear resistance and corrosion resistance, and is suitable for extreme ultraviolet optical systems. Single point diamond turning(SPDT) is the most typical processing method of nickel-phosphorus alloy, but it will leave periodic turning tool marks, resulting in poor roughness. Therefore, further ultra-smooth polishing is required after turning. In this paper, the ultra-smooth polishing process of nickel-phosphorus alloy is studied in detail, and a combined polishing process is proposed. By combining two polishing processes, magnetorheological polishing(MRP) and small tool polishing(STP), the full-band error convergence of nickel-phosphorus alloy can be realized effectively. Firstly, the polishing effects of magnetorheological polishing and small tool polishing on nickel-phosphorus alloy were studied respectively. Then, a nickel-phosphorus plane mirror with a diameter of 50mm was processed by combining these two polishing processes. The low-frequency surface error of Sq 0.012λ, midfrequency roughness of Sq 0.730nm and high-frequency roughness of Sq 1.62nm were achieved. The method of combining magnetorheological polishing with small tool polishing proposed in this paper uses magnetorheological polishing to quickly remove the turning tool marks, reduce low and medium frequency errors, and then uses small tool polishing to clean the iron powder left by magnetorheological polishing, reduce medium and high frequency errors while maintaining low frequency surface accuracy. The experimental result shows that the combined polishing process has strong feasibility, and the processing effect is much better than that of the single polishing process, which broadens the optional route of ultra-smooth polishing of ultra-ultraviolet optical components.
Keywords: Nickel-phosphorus alloy, Magnetorheological polishing, Small tool polishing, Combined polishing process, Full-band error.
