Accession Number : AD0914187

Title :   Thermophysical Properties of Thermal Energy Storage Materials - Aluminum.

Descriptive Note : Physical sciences research papers,

Corporate Author : AIR FORCE CAMBRIDGE RESEARCH LABS HANSCOM AFB MA

Personal Author(s) : Leiby, Clare C., Jr. ; Ryan, Thomas G.

Report Date : 18 JUL 1973

Pagination or Media Count : 33

Abstract : In response to RN-AFAPL-08-72-8, a program was initiated to determine the compatibility of Inconel canisters with specific thermal energy storage materials. A uniform temperature vacuum oven and and a 100-min (65 min on and 35 min off) oven control were designed and constructed. The timer-oven system generates the thermal cycle of an energy storage canister in near-earth orbit. An X-750 alloy canister was fabricated, precipitation-hardened, loaded with 215 gm of pure aluminum, and sealed off under high vacuum. It was then fitted with six thermocouples and placed in the oven for a 5000-hr test. Initial temperature measurements indicated that the aluminum alternately melted and froze during each temperature cycle. After 48 hr, only partial melting occurred. After 9 days of continuous cycling, all melting had ceased and the test was terminated. It was found that the canister had ruptured and that its contents were extremely hard. Electron microprobe analysis revealed the contents to be an aluminum-nickel-chromium-iron alloy with a density of 3.2 gm/cc (vs 2.7 gm/cc for pure aluminum). It is evident that the canister material was dissolved by the molten aluminum and that the coefficient of thermal expansion of the resulting alloy was large enough to cause the canister to rupture explosively. Preparations are under way for similar tests using eutectic mixtures of alkali fluorides. (Author)

Descriptors :   *ENERGY CONVERSION), (*REFRIGERATION SYSTEMS, CRYOGENICS), (*ALUMINUM, (*NICKEL ALLOYS, COMPATIBILITY), (*CONTAINERS, NICKEL ALLOYS), THERMAL EXPANSION, HEAT TRANSFER, LIQUID METALS, FREEZING, PHASE STUDIES, SOLIDS, HEATING, SOLAR RADIATION, COOLING, MELTING, SPACECRAFT COMPONENTS, HEAT OF FUSION, INFRARED DETECTORS, THERMODYNAMICS, IRON ALLOYS, VACUUM APPARATUS, RUPTURE, CAPILLARY TUBES, LABORATORY FURNACES.

Subject Categories : Properties of Metals and Alloys
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE