Accession Number : AD0421589

Title :   IMPROVED OXIDATION RESISTANCE OF MOLYBDENUM BY ALLOYING WITH HAFNIUM.

Descriptive Note : Final rept., 1 Nov 61-31 Aug 63.

Corporate Author : COLORADO SCHOOL OF MINES GOLDEN

Report Date : 03 SEP 1963

Pagination or Media Count : 112

Abstract : Preferential oxidation of a thermodynamically active metal component in a binary molybdenum base alloy has been used sucessfully to study the kinetics and mechanism of oxidation of that alloy and to determine the diffusion coefficient of the active component in the alloy. The system chosen was molybdenum-hafnium. Diffusion coefficients for hafnium in molybdenum were independently predicted by suitable modification of the equation for self diffusion developed by Sherby and Simnad, and combining this equation with the Dushman - Langmuir equation. The method allows for calculation of the activation energy E, and the frequency factor A, from existing data for the diffusion of zirconium in tungsten. The diffusion coefficients which were calculated by this method checked the ones which were obtained by the selective oxidation method quite well. (Author)

Descriptors :   (*MOLYBDENUM ALLOYS, HAFNIUM ALLOYS), (*HAFNIUM ALLOYS, MOLYBDENUM ALLOYS), OXIDATION, EXPERIMENTAL DATA, DIFFUSION, PENETRATION, MATHEMATICAL ANALYSIS, EQUATIONS, OXYGEN, HEAT OF ACTIVATION, FREQUENCY, ZIRCONIUM ALLOYS, TUNGSTEN ALLOYS, REACTION KINETICS, THERMODYNAMICS

Distribution Statement : APPROVED FOR PUBLIC RELEASE