Accession Number : AD0480103

Title :   PROGRAM ASTEC (ADVANCED SOLAR TURBO ELECTRIC CONCEPT). PART II. HIGH-TEMPERATURE MATERIALS LABORATORY TESTS.

Descriptive Note : Final technical rept. 1 Jul 64-1 Aug 65,

Corporate Author : LOCKHEED MISSILES AND SPACE CO INC SUNNYVALE CA

Personal Author(s) : Hurtt, W. W. ; Cunnington, G. R. ; Funai, A. I. ; Grammer, J. G. ; Karlak, R. F.

Report Date : JAN 1966

Pagination or Media Count : 162

Abstract : Temperature flux sensors and materials used for radiative cooling at elevated temperature conditions must be stable for extended periods of time in a vacuum and be unaffected by the stresses due to thermal cycling imposed by an orbit which takes the system repeatedly into and out of the earth's shadow. There are only limited low-temperature data available on those materials which are suitable for use at elevated temperatures in the space vacuum and under prolonged thermal cycling conditions. A laboratory program was conducted in which material specimens were prepared, measurement was made of their radiative properties in a vacuum as a function of temperature, evaluations were made of the mechanical integrity of the materials under thermal cycling conditions, and determination of the materials radiative property stability at prolonged elevated temperature was made. In addition, evaluation of thermoelectric output stability of several refractory metal thermocouple elements, as a function of exposure time and thermal cycling, was accomplished. Plasma-arc sprayed alumina on tantalum (3000 R) and thoria on tantalum (at 3500 R) appeared to be the best thermal control coatings tested. The stability of the tungsten-5% rhenium/tungsten-26% rhenium sensor material was good to 4000 R. (Author)

Descriptors :   *HIGH TEMPERATURE), (*REFRACTORY COATINGS, SPACE ENVIRONMENTS), (*HEAT RESISTANT MATERIALS, ALUMINUM COMPOUNDS, TUNGSTEN, OXIDES, STABILITY, COMPATIBILITY, SPRAYS, PLASMA JETS, TEMPERATURE, MEASUREMENT, SPECTROSCOPY, THERMAL STRESSES, MICROSTRUCTURE, THERMAL RADIATION, THORIUM COMPOUNDS, RHENIUM, DIOXIDES, BORIDES, CARBIDES, OXIDES, NITRIDES, SILICIDES, TANTALUM, X RAY DIFFRACTION, TEST METHODS, INSTRUMENTATION, CALIBRATION.

Subject Categories : Astrophysics
      Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE