Optically black cobalt surface
AssigneeMartin Marietta Corporation
InventorsDonald F. Shepard, Robert J. Fenolia
Life of this patent
Estimating the term…
Abstract
The present invention resides in the discovery that an optically black electroplated cobalt/cobalt oxide surface which has been anodized and then preferably calcined has both a high emissivity and high absorptivity, and is stable against loss of absorptivity at temperatures of more than 450.degree. C. for prolonged periods. Preferably, the optically black cobalt oxide surfaces of the present invention have an absorptivity of at least about 0.96 and an emissivity of at least about 0.6.
Claims13
An article having a an electroplated cobalt/cobalt oxide surface thereon which has been anodized, having an absorptivity of at least about 0.95 and an emissivity in the range of about 0.4-0.8, which is stable at temperatures of more than 450.degree. C. for prolonged periods.
A method for the preparation of optically black cobalt/cobalt oxide surfaces having an absorptivity of at least about 0.95 and an emissivity in the range of about 0.4-0.8, which are stable against loss of absorptivity when exposed to temperatures in excess of 450.degree. C. for prolonged periods, comprising the steps of:
- (a) electroplating metallic cobalt from an electroplate bath onto a substrate;
- and
- (b) anodizing said electroplated surface under anodizing conditions.
A method for the preparation of optically black cobalt/cobalt oxide surfaces having an absorptivity of at least about 0.95 and an emissivity in the range of about 0.4-0.8, which are stable against loss of absorptivity when exposed to temperatures in excess of 450.degree. C. for prolonged periods, comprising the steps of:
- (a) electroplating metallic cobalt from an electroplating bath onto a substrate to produce an electroplated cobalt surface having an absorptivity of at least about 0.80 and an emissivity of at least about 0.08;
- and
- (b) anodizing said cobalt surface under anodizing conditions.
Dependencies are inferred from the claim text.