| 摘要 |
PURPOSE:To produce a pore-less and distortion-free surface film having the surface roughness of a prescribed value or below by forming a glass coating film on the surface of a substrate consisting of an ceramic material having a prescribed density, then subjecting to polishing by a liquid suspended with a metallic oxide under velative lapping load. CONSTITUTION:The glass coating film having a specified value or below of a difference in the coefft. of thermal expansion and having, for example, >=400 deg.C softening point is formed on the surface of the substrate consisting of the Al ceramic material having the fine pores of a specified size or below and having, for example, >=90% relative theoretical density and is subjected to a hot hydrostatic press treatment. Such coating film is subjected to polishing by the liquid preped. by suspending at lease one one kind among Fe2O3, SiO2, MgO, CaO2 or Al2O3 having a specified size into pure water under, for example, 0.05-2kg/cm<2> relative lapping load. The glass coating film which has the pore-less and distortion-free surface having the specified value or below of the surface roughness and has a prescribed thickness is thus formed. |
