Microstructure of a black chrome solar selective absorber

Conference · Tue Aug 01 04:00:00 EDT 1978

OSTI ID:6390848

Lampert, C M

The structure of Harshaw Chemicals' CHROM-ONYX type of black chrome/metal selective absorber was studied to gain a better understanding of its influence upon the mechanism of wavelength selectivity. Spectral reflectance measurements were performed on seven samples. In this study, the best selectivity was found by these measurements to be 1.0 micron of black chrome on copper and 0.7 micron of black chrome on nickel. Both transmission and scanning electron microscopy were employed to study microstructure and chemical composition. As a result of the combined studies, some effects of black chrome thickness and the metallic substrate were determined. It was found that black chrome consisted of a very fine metallic distribution of particles of chromium, possibly suspended within a matrix of an oxide of chromium. This combination was, in turn, agglomerated into larger particles within the 0.05--0.3 micron size range. These larger particles formed a network which constituted the surface coating.

• Research Organization: California Univ., Berkeley (USA). Lawrence Berkeley Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6390848
• Report Number(s): LBL-8022; CONF-780829-9
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
141000* -- Solar Collectors & Concentrators
36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
ABSORPTIVITY
BLACK CHROME
BLACK COATINGS
CHEMICAL COMPOSITION
COATINGS
CRYSTAL STRUCTURE
DEPOSITION
DIMENSIONS
ELECTRON MICROSCOPY
EMISSIVITY
MICROSCOPY
MICROSTRUCTURE
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
REFLECTIVITY
SOLAR ABSORBERS
SPECTRALLY SELECTIVE SURFACES
SUBSTRATES
SURFACE COATING
SURFACE PROPERTIES
SURFACES
THICKNESS