Thermal degradation of a black chrome solar selective absorber coating: short term

Conference · Tue May 01 04:00:00 EDT 1979

OSTI ID:6272105

Lampert, C M

Both the energy absorption properties and chemical microstructure of CHROM-ONYX were investigated using electron microscopy and X-ray diffraction techniques. Different temperatures for short annealing times were used to evaluate this coating's temperature resistance limitations along with possible degradation mechanisms for various stagnation situations. Samples were tested in both air and vacuum. As a result, each sample regardless of atmosphere was characteristically similar, with air acting to mildly accelerate optical degradation at higher temperatures. Below 300 to 400/sup 0/C black chrome exhibited a structural transformation precipitating Cr/sub 2/O/sub 3/. Above 500/sup 0/C this phase grew considerably, while chromium was depleted. At 600/sup 0/C and above, a new dominant phase developed corresponding to NiCr/sub 2/O/sub 4/, a cubic spinel. However, for all practical purposes black chrome optically degraded between 500 to 600/sup 0/C during short exposure times.

• Research Organization: California Univ., Berkeley (USA). Lawrence Berkeley Lab.; California Univ., Berkeley (USA). Dept. of Materials Science and Mineral Engineering
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6272105
• Report Number(s): LBL-8857; CONF-790541-37
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
141000* -- Solar Collectors & Concentrators
ANNEALING
BLACK CHROME
BLACK COATINGS
CHALCOGENIDES
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
COATINGS
COHERENT SCATTERING
COPPER
DEPOSITION
DIFFRACTION
ELECTRODEPOSITION
ELECTROLYSIS
ELECTROPLATING
ELEMENTS
HEAT TREATMENTS
LYSIS
METALS
NICKEL COMPOUNDS
NICKEL OXIDES
OXIDES
OXYGEN COMPOUNDS
PLATING
PRECIPITATION
SCATTERING
SEPARATION PROCESSES
SOLAR ABSORBERS
SPECTRALLY SELECTIVE SURFACES
STAGNATION
SURFACE COATING
SURFACES
THERMAL DEGRADATION
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY DIFFRACTION