Accession Number : AD0809834

Title :   USE OF KRYPTONATES IN MATERIALS RESEARCH.

Descriptive Note : Summary technical rept. 31 Dec 65-30 Apr 66,

Corporate Author : PARAMETRICS INC WALTHAM MA

Personal Author(s) : Goodman, Philip ; Ronayne, Michael R., Jr

Report Date : DEC 1966

Pagination or Media Count : 61

Abstract : Studies were continued to investigate the applicability of the Kryptonate technique for the detection and measurement of surface alteration rates. Kryptonates are solids which have been impregnated with radioactive Kr(85). The rate of loss of Kr(85) from the surface reflects the rate of surface disturbance with great sensitivity. It has earlier been shown that this technique can detect phase changes in solids and can measure maximum surface temperature. Primary emphasis has been placed upon oxidation reactions in this continuation phase. The release rate of Kr(85) from Kryptonated Ta, W, B and MoSi2 has been followed simultaneously with the oxygen consumption rate and has been shown to be a direct reflection of the sample oxidation rate. Methods were developed for obtaining reproducible kinetic data. Oxidation rates for W measured by the Kryptonate technique agreed well in many respects with the results obtained by other techniques. Indications were found that the initial oxidation rate of an oxygen covered W surface is not necessarily identical with the steady state oxidation rate under all conditions. Oxidation and/or reaction of a substrate under a coating has been shown to be measurable by means of the Kryptonate technique. The loss of Kr(85) during application of an oxidatively protective coating appears indicative of the efficacy of the coating. Degradation of the protective properties of the coating during oxidation was also detected.

Descriptors :   *REACTION KINETICS), (*KRYPTON, DETECTION), (*OXIDATION, (*REFRACTORY METALS, OXIDATION), PHASE STUDIES, PROTECTIVE TREATMENTS, TANTALUM, TUNGSTEN, RADIOACTIVE ISOTOPES, COATINGS, SURFACES, SURFACE TEMPERATURE, EXPERIMENTAL DATA, OXIDES.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Coatings, Colorants and Finishes
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE