Accession Number : AD0275461

Title :   KINETICS OF FORMATION AND REVERSION OF GUINIER-PRESTON ZONES IN ALUMINUM-BASE ALLOYS

Corporate Author : AIR FORCE OFFICE OF SCIENTIFIC RESEARCH ARLINGTON VA

Personal Author(s) : HERMAN,H. ; FINE,M.E.

Report Date : APR 1962

Pagination or Media Count : 1

Abstract : This report includes: REVERSION AND REFORMATION GP I IN Al-1.7 AT .PERCENT Cu, by H. Herman and M. E. Fine. Apr 62. FORMATION AND REVERSION OF GUINIER-PRESTON ZONES IN Al-5.3 AT .PERCENT Zn, by H. Herman, J. B. Cohen, and M. E. Fine. Apr 62. Revision and reformation of GP I in Al-1.7 at.% Cu: K INETICS OF REVERSION AND REFORMATION OF GP I were studied resistometrically in this alloy. The revision is over in about 1/2 min at 205 C, irrespective of the amount of primary aging. After revision the occurrence of incubation time before reaging was substantiated. Plastic deformation drastically accelerates the reaging kin ics. An incubation time is observed only if the specimen is aged before reversion. Incubation time and the effect of plastic deformation indicated that ucleation of GP I is heterogeneous. Formation and reversion of GP zo es in Al-5.3 at.% Zn: Studies were made by measurement of electrical resistance, Young's modulus, critical resolved shear stress and x-ray scattering. After a long aging treatment, about 1/2 of the Zn atoms are associated with zones; after a long reaging treatment, about 1/4 are associated with zones.

Descriptors :   *AGING (PHYSIOLOGY), *ALUMINUM ALLOYS, *COPPER ALLOYS, *CREEP, *CRYSTAL LATTICES, *CRYSTAL STRUCTURE, *DEFORMATION, *KINETIC THEORY, *PHASE STUDIES, *SOLID STATE PHYSICS, *SOLIDS, *SOLUTIONS(MIXTURES), *ZINC ALLOYS

Distribution Statement : APPROVED FOR PUBLIC RELEASE