Title:
FORMING METHOD FOR SOLAR ENERGY SELECTIVE ABSORTION FILM ON SURFACE OF ALUMINUM MATERIAL
Document Type and Number:
Japanese Patent JPS5723095
Kind Code:
A
Abstract:
PURPOSE:To form the titled absorption film having excellent selective absorption properties, by performing the anodic oxidation treatment of an Al material containing a small amount of Cu, Si and Fe and then by electrolytically treating the material in an aqueous solutioh containing a metallic salt. CONSTITUTION:The anodic oxidation treatment of an Al material comprising an Al alloy cntaining 0.005-0.10% Cu, 0.6% or less Si and 0.6% or less Fe in carried out. When the content of Cu is in the above-mentioned range, the anodic oxide film being formed has an improved transparency and the growth of the film is restrained so that a thin stable film can be formed. As a result, the finally formed selective absorption film has has an improved performance. In pasticular, it has a small radiation ratio. Since Si and Fe degrade the radiation rate, the small content thereof is preferable so that the content of each of them is limited to a value of 0.6% or less. After the oxide film treatment, the Al material is electrolytically treated in an electrolytical liquid containing a metallic salt to blacken the anode oxide film and thus the film having excellent selective absorption properties for solar energy can be formed.
Inventors:
INOUE SUSUMU
Application Number:
JP9668680A
Publication Date:
February 06, 1982
Filing Date:
July 14, 1980
Export Citation:
Assignee:
SHOWA ALUMINIUM CO LTD
International Classes:
C25D11/04; C25D11/22; F24J2/48; (IPC1-7): C25D11/22; F24J3/02
Domestic Patent References:
| JP42024731A | ||||
| JPS4920463A | 1974-02-22 | |||
| JPS5327215A | 1978-03-14 | |||
| JP43022496A |