Accession Number : AD0649274

Title :   THERMAL CONDUCTIVITY OF ALUMINUM OXIDE.

Descriptive Note : Technical rept., 1 Sep 65-31 Aug 66,

Corporate Author : CINCINNATI UNIV OHIO MATERIALS SCIENCE PROGRAM

Personal Author(s) : Hoch,M. ; Silberstein,A.

Report Date : NOV 1966

Pagination or Media Count : 28

Abstract : The method developed earlier in our laboratory to measure thermal conductivity of materials at elevated temperatures has been applied to aluminum oxide. Aluminum oxide discs, 1/4 to 3/4 inches in diameter and variable height and grain size, were enveloped along the cylindrical surface in thin (0.001 inches thick) platinum foils. The platinum foil was heated by induction to 1500-1800K and it, in turn, heated the aluminum disc through radiation. The temperature distribution along the flat surface of the sample could be divided into two parts: toward the center of the sample, only volume (lattice and radiation) conduction was present; at the edge of the sample, the temperature rose rapidly, indicating a finite absorption zone. In this zone, the absorption of the radiation from the platinum heater is not complete yet, and therefore, the temperature distribution and heat transmission in the sample is influenced by the properties of the platinum. (Author)

Descriptors :   (*THERMAL CONDUCTIVITY, *ALUMINUM COMPOUNDS), OXIDES, TEMPERATURE, PLATINUM, ABSORPTION, MEASUREMENT, THERMAL RADIATION

Subject Categories : Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE