Accession Number:

AD0613741

Title:

THE STRAIN-RATE DEPENDENCE OF THE FLOW STRESS OF COPPER SINGLE CRYSTALS,

Descriptive Note:

Corporate Author:

CAMBRIDGE UNIV (ENGLAND) CAVENDISH LAB

Report Date:

1961-06-16

Pagination or Media Count:

22.0

Abstract:

An experimental study is described of the strain-rate sensitivity of the flow stress of Cu single crystals in all stages of deformation and over a wide temperature range. The curves relating the increase in flow stress on increasing the strain-rate by a fixed amount to the flow stress are generally divisible into three regions a, b and c. Region a is linear and characteristic of easy glide. At the end of this region the rate of stress increase with strain increases, and a transition region, b, occurs in which the stress increase varies with flow stress much more slowly than in easy glide. Another linear region, c, of the stress increase versus flow stress, of intermediate slope, begins during stage II and is characteristic of the latter part of stage II and of stage III of the work-hardening curves. The lower the test temperature, the greater is the range in stage II in which the linear region c applies. There is no change in the curves of the stress increase versus flow stress at the onset of stage III. The slope of region c is similar for crystals deforming by single or double slip, and is of the same order of magnitude as that for polycrystals. The results agree with those of previous workers in that the temperature dependence of the flow stress is greater during easy glide than in stages II and III. The two linear regions, a and c, are thought to correspond to two different arrangements of dislocations, the transition from one type of arrangement to the other taking place in region b. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE