| 摘要 |
PURPOSE:To obtain a solar-heat absorbing element having a superior durability and a high heat absorbing efficiency, that is used in a solar-heat utilizing water heater or the like, by forming a selective absorption film consisting of copper oxide on the surface of a base member with a thermally and chemically stable plating layer being interposed therebetween. CONSTITUTION:A base member 2 of a solar-heat absorbing element 1, consisting principally of iron, has a superficial layer 2a formed with fine ruggedness, and a thermally and chemically stable plating layer (for instance, nickel or chromium plate layer) 3 is applied over the superficial layer 2a to such an extent as may not affect the fine ruggedness thereon. Then, a thin layer of copper or a copper alloy is formed over the surface of the plating layer 3 and it is converted into a selective absorption film 4 consisting principally of copper oxide and having a thickness of 100-7,000Angstrom by subjecting the same to oxidation. By thus forming a rugged, selective absorption film 4 over the surface of the base member 2 by the intermediary of the plating layer 3, it is enabled to improve heat-resisting performance of the heat absorbing element and to raise the solar-heat absorbing efficiency. |
