DETERMINATION OF THE EMISSIVITY OF MATERALS. Progress Report, January 1 through June 30, 1963
Emittance measurements were made and the long-term endurance tests were concluded. The total hemispherical emittandce rig has been returned to service and the quality of temperature measurement has been investigated. An analysis of slurry coating procedures is being conducted. Total hemispherical emittance measurements were made and are reported for AISI-310 stainless steel, tantalum, andd coatings of crystalline boron, nickel-chrome spinel, calcium titanate, and iron titanate. All coating materials were plasma-arc sprayed onto niobium- 1 per cent zirconium tubes. Emittance values of 0.87 or above were obtained with coatings of nickel-chrome spinel, calcium titandate, andd iron titandate. An endurance test conducted on a calcium--titanate coated specimen resulted in lower emittance values than andticipated but these values are not believed to be characteristic of this coating. Endurance tests were not completed for nickel- chrome spinel or iron titanate coatings. An aluminum-phosphate bonded mixture of nickel-chrome spinel and silicon dioxide on a SNAP-8 finned-tube radiator segment completed 15,000 hours of endurance testing. Flame-sprayed coatings of titania on SNAP-8 and Sunflower I sections completed 14,037 and 13,755 hours respectively. A fourth rig containing a SNAP-8 section with an aluminumphosphate bonded mixture of silicon carbide andd silicon dioxide completed 12,781 hours of testing. Ail tests have been terminated and the coated segments are being maintained in vacuum at ambient temperatures pending post-test analysis. The difficulties arising from the volatilization of mandgandese oxide in the total hemispherical emittance rig have been resolved and the rig was returned to service. The quality of black- body hole configurations was re-evaluated and results substantiated previous analytical work. The new evaluation included the investigation of the effects of specimen misalignment and variations in chamber geometry. In conjunction with these investigations it has been found that, on the average, optical pyrometer temperature indications are 8 deg F higher than thermocouple indications. This problem is under investigation. An investigation of Alkaphos bonded coating proeedures was conducted with attention being directed toward the bonding of silicon carbide. Nineteen tests were conducted using various surface preparation, drying, and curing procedures as well as various slurry compositions. The best procedure found to date requires 20 hours of air drying followed by oven curing at 200 deg F for 2 hours, 250 deg F for 2 hours, 300 deg F for 2 hours, and 400 deg F for 2 hours. (auth)
- Research Organization:
- Pratt and Whitney Aircraft Div., United Aircraft Corp., Hartford, Conn.
- NSA Number:
- NSA-18-005737
- OSTI ID:
- 4154070
- Report Number(s):
- PWA-2255; N63-22882
- Resource Relation:
- Other Information: Orig. Receipt Date: 31-DEC-64
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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DETERMINATION OF THE EMISSIVITY OF MATERIALS. Quarterly Progress Report, July 1 through September 30, 1963
DETERMINATION OF THE EMISSIVITY OF MATERIALS. Quarterly Progress Report, July 1-September 30, 1962
Related Subjects
ALUMINUM OXIDES
ALUMINUM PHOSPHATES
BONDING
BORON
CALCIUM COMPOUNDS
CHROMIUM OXIDES
COATING
ELECTRIC ARCS
EMISSION
FILMS
IRON COMPOUNDS
MAGNESIUM OXIDES
MEASURED VALUES
MINERALS
NICKEL OXIDES
NIOBIUM ALLOYS
OXIDES
PLANTS
PLASMA
SILICON OXIDES
SNAP-8 SERIES
SPINELS
STAINLESS STEELS
SUNFLOWERS
TANTALUM
TITANIUM OXIDES
TUBES
ZIRCONIUM ALLOYS