Fig. 1. Process flow of precision mirror grinding

Fig. 2. Illustration of grinding machine

Fig. 3. Illustration of aspherical vertical grinding

Fig. 4. Effect of A-axis zero-position error on surface form accuracy (PV)

Fig. 5. Experimental results of the surface form accuracy (PV). (a) \begin{document}$\Delta \theta = $\end{document}\begin{document}$ {0^ \circ }$\end{document}; (b) \begin{document}$ \Delta \theta = {0.001^ \circ } $\end{document}

Fig. 6. Effect of Y-axis alignment error on surface form accuracy (PV)

Fig. 7. Y bias d_b=70 μm experimental results of the surface form accuracy (PV)

Fig. 8. Experimental results of the surface form accuracy (PV). (a) r=59.690 mm; (b) r=59.640 mm

Fig. 9. Experimental results of the surface form accuracy (PV). (a) Three-axis spiral scanning-path; (b) Four-axis spiral scanning-path; (c) Three-axis raster scanning-path

Fig. 10. Experimental results of the surface form accuracy (PV). (a) With-out accuracy compensation; (b) With accuracy compensation

Fig. 11. Flow chart two kinds of damage depth prediction models established

Fig. 12. Relationship between subsurface damage layer and surface roughness

Fig. 13. (a)-(c) Grinding marks after grinding with the D20 metal base, D20 resin base and D10 resin base grinding wheels; (d)-(f) Surface morphology and subsurface damage after grinding with the D20 metal base, D20 resin base and D10 resin base grinding wheels

Fig. 14. Surface roughness and subsurface damage depth after grinding with different grinding wheels

Fig. 15. Surface roughness and subsurface damage depth under different grinding depth (a), spindle speed (b) and feed speed (c)

Fig. 16. Surface roughness and subsurface damage depth under different grinding parameters