Stress relaxation and dynamic recovery in cobalt at low temperatures

Journal Article · Sat Jun 01 04:00:00 EDT 1963 · Philosophical Magazine

DOI:https://doi.org/10.1080/14786436308214458· OSTI ID:4687378

Feltham, P.

Stress relaxation in polycrystalline cobalt of 99.999% purity was studied at constant strains of up to 8% at 77384 deg K. After the application of a small plastic strain increment the applied tensile stress sigma diminished logarithmically with time; from the variation of the slopes of the isothermal relaxation curves with temperature and prestrain the rate controlling energy barrier was determined to be 1.61 plus or minus 0.1 ev. This appears to be related to the formation of vacancies by intersection jogs dragged by basal dislocations. The relaxation contributed to dynamic recovery, manifest in the linear decrease of the coefficient of parabolic work-hardening d sigma /sup 2//d epsilon from 18.3 x 10/sup 7/ at 77 deg K to 5.8 x 10 Kg/sup 2//cm/sup 4/ at 384 deg K. (auth)

• Research Organization: The University, Leeds, Eng.
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-027867
• OSTI ID: 4687378
• Journal Information: Philosophical Magazine, Journal Name: Philosophical Magazine Journal Issue: 90 Vol. 8; ISSN 0031-8086
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

COBALT
COLD WORKING
DEFECTS
DEFORMATION
DIAGRAMS
DISLOCATIONS
EQUATIONS
HARDNESS
LOW TEMPERATURE
METALS, CERAMICS, AND OTHER MATERIALS
RECOVERY
STRESSES
TEMPERATURE
TENSILE PROPERTIES