| 摘要 |
PURPOSE:To prepare a light deflector having superior corrosion resistance and chemical resistance by processing each small flat surface of a polyhedron contg. Al to a smooth and flat face and performing electroplating thereon with an Ni-P alloy having a specified comspn. and finishing the plated surface to a mirror finished surface. CONSTITUTION:An element body 10 of a mirror for a regular hexagonal prism- shaped light deflector is prepd. from Al or an Al alloy, the element is defatted for the pretreatment of plating with a solvent such as trichloroethylene, and defatted further with a surface active agent, treated further by a zinc immersion process. The product is then treated by Cu strike plating in a copper cyanide bath, further a plated layer 11 having about 60mum thickness of an Ni-P alloy contg. about 10-15% P is formed by electroplating. Each small flat face of the plated layer 11 is finished by lapping to a mirror face with <=0.01mum face roughness and about lambda/10nm ultimate flatness. Finally, Al vapor deposited layer 12 and an SiO2 vapor deposited layer 13 are formed as protective layers and a fitting hole 70 is formed. A mirror body 60a for a light deflector is thus obtd. |
