Thermal degradation of a black chrome solar selective absorber coating: short term
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
- Resource Relation:
- Conference: International Solar Energy Society meeting, Atlanta, GA, USA, 28 May 1979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BLACK CHROME
THERMAL DEGRADATION
BLACK COATINGS
SOLAR ABSORBERS
ANNEALING
CHROMIUM OXIDES
COPPER
ELECTROPLATING
NICKEL OXIDES
PRECIPITATION
SPECTRALLY SELECTIVE SURFACES
STAGNATION
X-RAY DIFFRACTION
CHALCOGENIDES
CHROMIUM COMPOUNDS
COATINGS
COHERENT SCATTERING
DEPOSITION
DIFFRACTION
ELECTRODEPOSITION
ELECTROLYSIS
ELEMENTS
HEAT TREATMENTS
LYSIS
METALS
NICKEL COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATING
SCATTERING
SEPARATION PROCESSES
SURFACE COATING
SURFACES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
141000* - Solar Collectors & Concentrators