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Initial aging phenomena in copper-chromium alloysThe effects of quenching and aging temperatures on the initial aging curves of Cu-Cr alloy were examined mainly by means of electrical resistivity measurements. Three Cu-Cr alloy specimens having 0.24, 0.74, and 1.0% Cr were solution-treated at 950-1050 C, quenched into ice-water, and subsequently aged at 300-500 C. The results were as follows: (1) At the very early stage of aging (within about 30 sec), an abrupt decrease of resistivity with lowering aging tempratures. (T sub A) and rising solution temperatures (T sub S) was observed at (T sub A) up to about 400 C. In contrast, a transient increase of resistivity with rising T sub A and lowering T sub S was observed at T sub A from about 450 to 500 C. These phenomena seem to be caused by a rapid formation of solute clusters and the reversion of clusters formed during quenching, which are enhanced by quenched-in vacancies, respectively. (2) The amount of precipitation increased at the latter stage of aging with rising T sub S and T sub A as generally expected, where T sub S was not so high as to form secondary defects. (3) As a result, the initial aging phenomena in Cr-Cr alloy were revealed to be complicated against expectations. This was considered to be due to the migration energy of vacancies so larger in Cu-base.
Document ID
19850010760
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Suzuki, H.
(NASA Headquarters Washington, DC United States)
Motohiro, K.
(NASA Headquarters Washington, DC United States)
Date Acquired
September 5, 2013
Publication Date
January 1, 1985
Subject Category
Metallic Materials
Report/Patent Number
NAS 1.15:77790
NASA-TM-77790
Accession Number
85N19070
Funding Number(s)
CONTRACT_GRANT: NASW-4006
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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