Novel orthogonal velocity polishing tool and its material removal characteristics from CVD SiC mirror surfaces

Abstract

A new and patented polishing tool called Orthogonal Velocity field Tool (OVT) was built and its material removal characteristics from Chemical Vapor Deposition Silicon Carbide (CVD SiC) mirror surfaces were investigated in this study. The velocity field of OVT is produced by rotating the bicycle type tool in the two orthogonal axes, and this concept is capable of producing a material removal foot print of pseudo Gaussian shapes. First for the OVT characterization, we derived a theoretical material removal model using distributions of pressure exerted onto the workpiece surface, relative speed between the tool and workpiece surface, and dwell time inside the tool- workpiece contact area. Second, using two flat CVD SiC mirrors that are 150 mm in diameter, we ran material removal experiments over machine run parameter ranging from 12.901 to 25.867 psi in pressure, from 0.086 m/sec to 0.147 m/sec tool in the relative speed, and 5 to 15 sec in dwell time. Material removal coefficients are obtained by using the in-house developed data analysis program. The resulting material removal coefficient varies from 3.35 to 9.46 um/psi hour m/sec with a mean value of 5.90 ± 1.26(standard deviation). We describe the technical details of the new OVT machine, the data analysis program, the experiments, and the results together with the implications to the future development of the machine.

Research on nonlinear relationship between rotation speed and material removal in wheel polishing technology

“…Substitute equation (12) into equation (11) to get: The R-square is very close to 1, indicating a good fit between the fitted equation and the observations. Figure 3 shows the material removal rate data and fitting curve at different polishing speeds.…”

“…In 2016, H Seo proposed an orthogonal velocity field wheel polishing tool. The TIF of wheel polishing technology was theoretically analyzed and simulated by means of integral, and the TIF was verified by experiments to be close Gaussian and very stable [11] . In 2022, Yao processes high-precision aspheric optical components based on the wheel polishing technology of industrial robots [12] .…”

Dynamic tool influence function on SiC mirror surfaces for space optical telescopes using orthogonal velocity tool

“…[6,8] In this study, we report on the dynamic Tool Influence Function (TIF) patterns on SiC surfaces using the Orthogonal Velocity Tool (OVT) machine. [6,7,8] TIF is a crucial function that improves optical performance by controlling material removal and the resulting surface volume. [7,9] We observed the depth of material removal from dynamic TIF patterns.…”

“…[6,7,8] TIF is a crucial function that improves optical performance by controlling material removal and the resulting surface volume. [7,9] We observed the depth of material removal from dynamic TIF patterns. Based on the obtained results, KASI aims to enhance the surface quality of mirrors used in space optical telescopes.…”

Surface modification and fatigue properties of electrical discharge machined aluminum alloy 6061 using plasma etching

“…There are many kinds of surface treatment methods, and different surface treatments can enhance the different performances for various needs. The commonly used treatments include electroless plating, 1,2 electroplating, 3 plasma etching, [4][5][6] ceramic thin film cladding, 7 physical vapor deposition (PVD), 8,9 chemical vapor deposition (CVD), [10][11][12] micro arc oxidation (MAO), [13][14][15][16] plasma electrolytic oxidation (PEO) coating, 17 and so on.…”