A Study Of The Recrystallization Of Cold-worked Copper By Doppler Broadening Of Annihilation Radiation

Abstract

The recrystallization of oxygen-free high-conductivity copper cold rolled to 20, 37, 55 and 66% thickness reductions has been studied by monitoring the extent of Doppler broadening of the positron annihilation γ linewidth as a function of temperature during ramp annealing runs. The sharp change in the line-shape parameter S consistently observed between 100 and 200°C is attributed to the reduction in defect densities during recrystallization. These temperatures are about 100-200°C below those reported in earlier studies; this may be a consequence of the relatively low rate of temperature increase during annealing (2.2-50°C h−1), the purity of the samples used or the sample preparation history. The temperature at which recrystallization is seen to occur passes through a maximum at about 40% deformation. A measurement of S for the 20%-deformed sample as a function of time at a constant temperature implies that the recrystallization is a first-order process which follows an incubation period and which is in turn followed by grain growth. Recrystallized grain sizes have been measured for all samples and found to lie in a small range between 10 and 12.5 μm. These results are discussed in the light of earlier work on cold-worked copper by Doppler broadening and other techniques. © 1992 Taylor & Francis Group, LLC.

Department(s)

Materials Science and Engineering

International Standard Serial Number (ISSN)

0141-8610

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Taylor and Francis Grouup; Taylor and Francis, All rights reserved.

Publication Date

01 Jan 1992

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