| 摘要 |
The invention relates to a process for the production of optically selective surfaces for use in solar collectors, having a predetermined ratio of absorbance alpha s to emmitance epsilon of at least 10, which comprises effecting an anodic oxidation of copper, or copper applied to any substrate metal, in an alkaline bath at an elevated temperature between 50 DEG and 85 DEG C., preferably 70 DEG to 85 DEG C., and at a current density of above 1 mA/cm2 and up to 40 mA/cm2 until an increase of resistance is experienced. Substrate metals may be copper, copper plated steel, copper plated galvanized iron, copper plated nickel, nickel plated steel to which a layer of copper is applied, and the like.
|
