Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-30T21:33:38.240Z Has data issue: false hasContentIssue false

Characterization of aging behavior of precipitates and dislocations in copper-based alloys

Published online by Cambridge University Press:  29 February 2012

Shigeo Sato*
Affiliation:
Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Sendai, Miyagi, Japan
Yohei Takahashi
Affiliation:
Research Department, Nissan ARC, Ltd., 1 Natsushima, Yokosuka, Japan
Kazuaki Wagatsuma
Affiliation:
Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Sendai, Miyagi, Japan
Shigeru Suzuki
Affiliation:
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-Po1 Katahira, Sendai, Miyagi, Japan
*
a)Electronic mail: [email protected]

Abstract

The growth of precipitates in a deformed Cu–Ni–Si alloy with an aging treatment and the rearrangement of dislocations were investigated using small-angle X-ray scattering method and XRD line-profile analysis. The small-angle X-ray scattering method was used for characterizing the growth behavior of the precipitates. The results showed that the precipitates grew gradually to a few nanometers in radius when aged under the condition that the alloy exhibited a maximum of the hardness due to precipitation hardening. The growth rate rose from the onset of the overaging, where the hardness started to decrease. The line-profile analysis of copper-based alloy diffraction peaks using modified Williamson–Hall and modified Warren–Averbach procedures yielded a variation in the dislocation densities of the alloy as a function of the aging time. The dislocation density of the alloy before the aging treatment was estimated to be 1.7×1015 m−2 and its high value was held up to the peak-aging time. With the onset of the overaging, however, the dislocation density distinctly decreased by about 1 order of magnitude indicating that a large amount of the dislocations rearranged to release the alloy from the high dislocation-density state. The results suggest that the massive rearrangement of dislocations was accompanied with coarsening of the precipitates.

Type
Technical Articles
Copyright
Copyright © Cambridge University Press 2010

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Boistelle, R. and Astier, J. P. (1988). “Crystallization mechanisms in solution,” J. Cryst. Growth JCRGAE 90, 1430.10.1016/0022-0248(88)90294-1Google Scholar
Huang, F., Ma, J., Ning, H., Cao, Y., and Geng, Z. (2003). “Precipitation in Cu–Ni–Si–Zn alloy for lead frame,” Mater. Lett. MLETDJ 57, 21352139.10.1016/S0167-577X(02)01212-0CrossRefGoogle Scholar
Markandeya, R., Nagarjuna, S., and Sarma, D. S. (2005). “Effect of prior cold work on age hardening of Cu–4Ti–1Cr alloy,” Mater. Sci. Eng., A MSAPE3 404, 305313.10.1016/j.msea.2005.05.072Google Scholar
Brunner-Popela, J. B. and Glatter, O. (1997). “Small-angle scattering of interacting particles. I. Basic principles of a global evaluation technique,” J. Appl. Crystallogr. JACGAR 30, 431442.10.1107/S0021889896015749CrossRefGoogle Scholar
Stokes, A. R. (1948). “A numerical Fourier-analysis method for the correction of widths and shapes of lines on X-ray powder photographs,” Proc. Phys. Soc. 61, 382391.10.1088/0959-5309/61/4/311CrossRefGoogle Scholar
Suzuki, S., Shiblitani, N., Mimura, K., Isshiki, M., and Waseda, Y. (2006). “Improvement in strength and electrical conductivity of Cu–Ni–Si alloys by aging and cold rolling,” J. Alloys Compd. JALCEU 417, 116120.10.1016/j.jallcom.2005.09.037CrossRefGoogle Scholar
Takahashi, Y., Sanada, T., Sato, S., Okajima, T., Shinoda, K., and Suzuki, S. (2007). “SAXS and XAFS characterization of precipitates in a high-performance Cu–Ni–Si alloy,” Mater. Trans. MTARCE 48, 101104.10.2320/matertrans.48.101CrossRefGoogle Scholar
Ungar, T. and Borbely, A. (1996). “The effect of dislocation contrast on x-ray line broadening: A new approach to line profile analysis,” Appl. Phys. Lett. APPLAB 69, 31733175.10.1063/1.117951CrossRefGoogle Scholar
Ungar, T., Dragomir, I., Revesz, A., and Borbely, A. (1999). “The contrast factors of dislocations in cubic crystals: The dislocation model of strain anisotropy in practice,” J. Appl. Crystallogr. JACGAR 32, 9921002.10.1107/S0021889899009334CrossRefGoogle Scholar
Williamson, G. K. and Hall, W. H. (1953). “X-ray line broadening from filed aluminum and wolfram,” Acta Metall. AMETAR 1, 2231.10.1016/0001-6160(53)90006-6Google Scholar