TY - JOUR
T1 - Effect of cold rolling on the formation and distribution of nanoclusters during pre-aging in an Al-Mg-Si alloy
AU - Serizawa, A.
AU - Sato, T.
AU - Miller, M. K.
N1 - Funding Information:
Research at the Oak Ridge National Laboratory ShaRE User Facility was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy . The authors would like to thank Tokyo Institute of Technology Global COE Program – Education and Research Center for Material Innovation – ( FY2007-2011 ), which are fully sponsored by Japan Society for the Promotion of Science .
PY - 2013/1/20
Y1 - 2013/1/20
N2 - The effect of high densities of dislocations on the formation behavior of two types of nano-scale clusters (nanoclusters), which are formed at room temperature or during pre-aging at ~373. K in an Al-Mg-Si alloy, was investigated by atom probe tomography. Cold rolling was applied to modify the formation behavior and/or the characteristics of the nanoclusters and also the precipitation sequence, which involve both nanoclusters and a strengthening phase to improve the bake-hardening response. Nanoclusters formed during pre-aging tended to form along the dislocations. Cold rolling accelerated the preferential formation of the nanoclusters, whereas the number density of the nanoclusters decreased by cold rolling before pre-aging. However, the number density of the nanoclusters was considerably higher than that of the Β″ phase. Cold rolling before pre-aging enhanced the age-hardenability the most compared with other processes such as the contemporary pre-aging process. It is considered that the nanoclusters along dislocations lead to the preferential transformation to the Β phase and then the rapid growth of the Β″ phase. The nanoclusters formed on dislocations are effective in improving the bake-hardening response for the duration of the bake-hardening process. The kinetics and the distribution of the nanoclusters were found to be affected by the dislocations which were induced by cold rolling.
AB - The effect of high densities of dislocations on the formation behavior of two types of nano-scale clusters (nanoclusters), which are formed at room temperature or during pre-aging at ~373. K in an Al-Mg-Si alloy, was investigated by atom probe tomography. Cold rolling was applied to modify the formation behavior and/or the characteristics of the nanoclusters and also the precipitation sequence, which involve both nanoclusters and a strengthening phase to improve the bake-hardening response. Nanoclusters formed during pre-aging tended to form along the dislocations. Cold rolling accelerated the preferential formation of the nanoclusters, whereas the number density of the nanoclusters decreased by cold rolling before pre-aging. However, the number density of the nanoclusters was considerably higher than that of the Β″ phase. Cold rolling before pre-aging enhanced the age-hardenability the most compared with other processes such as the contemporary pre-aging process. It is considered that the nanoclusters along dislocations lead to the preferential transformation to the Β phase and then the rapid growth of the Β″ phase. The nanoclusters formed on dislocations are effective in improving the bake-hardening response for the duration of the bake-hardening process. The kinetics and the distribution of the nanoclusters were found to be affected by the dislocations which were induced by cold rolling.
KW - Al-Mg-Si alloys
KW - Atom probe tomography
KW - Bake-hardening response
KW - Dislocation-nanocluster interaction
KW - Hardness measurement
KW - Nanocluster
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U2 - 10.1016/j.msea.2012.10.070
DO - 10.1016/j.msea.2012.10.070
M3 - Article
AN - SCOPUS:84873526084
VL - 561
SP - 492
EP - 497
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
SN - 0921-5093
ER -