Accession Number : AD0289859

Title :   WORK HARDENING MECHANISMS IN BODY CENTERED CUBIC METALS

Corporate Author : PRATT AND WHITNEY AIRCRAFT MIDDLETOWN CONN

Personal Author(s) : GREGORY,DONALD P. ; ROWE,GEORGE H. ; STROH,ALAN N.

Report Date : SEP 1962

Pagination or Media Count : 1

Abstract : Analysis of a literature survey indicates that the following properties are important in governing the dislocation arrangement, and hence the work hardening mechanism, in a particular metal crystal: (1) number of slip systems and slip directions, (2) possibility of dislocation interactions to produce Lomer-Cottrell type barriers, (3) extension of dislocations, stacking fault energy (ease of climb and cross slip, formation of edge dipoles and elongated loops during deformation, multiplication of dislocations by double cross slip), (4) energy to form lattice vacancies or interstitial atoms by nonconservative motion of jogs in screw dislocations compared to the energy for conservative motion of the jogs along screw dislocations (whether or not point defects are formed during deformation), and (5) impurity atom-dislocation interactions (locking of sources). Results are presented of an experimental work hardening program with polycrystalline and single crystal columbium. (Author)

Descriptors :   *METAL CRYSTALS, CRYSTAL DEFECTS, CRYSTAL LATTICES, CRYSTAL STRUCTURE, IMPURITIES, NIOBIUM, SHEAR STRESSES, SINGLE CRYSTALS, TESTS, THEORY

Distribution Statement : APPROVED FOR PUBLIC RELEASE