THE SPECTRAL EMITTANCE AND LONG-TERM THERMAL STABILITY OF COATINGS FOR THERMOPHOTOVOLTAIC (TPV) RADIATOR APPLICATIONS

Conference · Sat Dec 01 04:00:00 EST 2001

OSTI ID:795691

COCKERAM, B V ^[1]; HOLLENBECK, J L

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1. Bettis Atomic Power Laboratory

Vacuum plasma spray coatings (Zr0[sub]2 + 18% Ti0[sub]2 + 10% Y[sub]20[sub]3, ZrC, Fe[sub]2Ti0[sub]5, ZrTi0[sub]4, Zr0[sub]2 + 8% Y[sub]0[sub]3 + 2% Hf0[sub]2, and Al[sub]20[sub]3 + Ti0[sub]2) have been developed to improve the emissivity of material surfaces under consideration for TPV radiator applications. These coated surfaces have been shown to be thermally stable at temperatures up to 1200 degree C for as much as 8000 hours and have produced a desired increase in the surface emissivity of molybdenum and niobium radiators. The spectral emissivity of these surfaces is measured before and after long-term vacuum anneals to determine the power density that would be provided to a TPV cell. The thermal stability of the coatings is further evaluated by characterization after long-term vacuum annealing. A kinetic model of the volatility of oxide phases is used to describe the excellent thermal stability of the coatings that possess the highest post-anneal emittance values (Zr0[sub]2 + 18% Ti0[sub]2 + 10% Y[sub]20[sub]3, ZrC, and Al[sub]20[sub]3 + Ti0[sub]2).

• Research Organization: Bettis Atomic Power Laboratory (BAPL), West Mifflin, PA
• Sponsoring Organization: USDOE
• DOE Contract Number: AC11-98PN38206
• OSTI ID: 795691
• Report Number(s): B-T-3382
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
ALUMINIUM OXIDES
COATINGS
EMISSIVITY
HAFNIUM OXIDES
IRON COMPOUNDS
KINETIC EQUATIONS
POWER DENSITY
RADIATORS
SPRAY COATING
STABILITY
THERMOPHOTOVOLTAIC CONVERTERS
TITANATES
TITANIUM OXIDES
VOLATILITY
YTTRIUM OXIDES
ZIRCONIUM CARBIDES
ZIRCONIUM OXIDES