TY - JOUR
T1 - Methods for designing concurrently strengthened severely deformed age-hardenable aluminum alloys by ultrafine-grained and precipitation hardenings
AU - Hirosawa, Shoichi
AU - Hamaoka, Takumi
AU - Horita, Zenji
AU - Lee, Seungwon
AU - Matsuda, Kenji
AU - Terada, Daisuke
N1 - Funding Information:
This research was supported by the JST (Japan Science and Technology Agency) under collaborative research based on industrial demand ‘‘Heterogeneous structure control: Towards innovative development of metallic structural materials.’’ S.H. thanks Prof. H. Okuda, Kyoto University, for helpful discussions on the SAXS measurement. The generous support by the Light Metals Educational Foundation of Japan and Japan Aluminum Association is also acknowledged.
PY - 2013/8
Y1 - 2013/8
N2 - The age-hardenings behavior and precipitate microstructures with high dislocation density and/or ultrafine grains have been studied for 6022Al-Mg-Si and 2091Al-Li-Cu alloys. The high-pressure torsion (HPT) specimen of the former alloy exhibited either suppressed age hardenings or even age softening, unlike in the cases of the undeformed and cold-rolled specimens, at room temperature (RT) to 443 K (170 C). On the other hand, the HPT specimen of the latter alloy successfully increased the hardness up to >HV290 at 373 K (100 C), suggesting that concurrent strengthening by ultrafine-grained and precipitation hardenings can be activated if both alloy system and aging temperature are optimally selected. The corresponding transmission electron microscopy (TEM) microstructures attributed such a high level of hardness to the transgranular precipitation of the nanometer-scale particles within ultrafine grains. From the results of in situ small-angle X-ray scattering (SAXS) measurements, methods to maximize the effect of the combined processing of severe plastic deformation (SPD) and the age-hardenings technique are proposed based on the underlying phase transformation mechanisms.
AB - The age-hardenings behavior and precipitate microstructures with high dislocation density and/or ultrafine grains have been studied for 6022Al-Mg-Si and 2091Al-Li-Cu alloys. The high-pressure torsion (HPT) specimen of the former alloy exhibited either suppressed age hardenings or even age softening, unlike in the cases of the undeformed and cold-rolled specimens, at room temperature (RT) to 443 K (170 C). On the other hand, the HPT specimen of the latter alloy successfully increased the hardness up to >HV290 at 373 K (100 C), suggesting that concurrent strengthening by ultrafine-grained and precipitation hardenings can be activated if both alloy system and aging temperature are optimally selected. The corresponding transmission electron microscopy (TEM) microstructures attributed such a high level of hardness to the transgranular precipitation of the nanometer-scale particles within ultrafine grains. From the results of in situ small-angle X-ray scattering (SAXS) measurements, methods to maximize the effect of the combined processing of severe plastic deformation (SPD) and the age-hardenings technique are proposed based on the underlying phase transformation mechanisms.
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U2 - 10.1007/s11661-013-1730-y
DO - 10.1007/s11661-013-1730-y
M3 - Article
AN - SCOPUS:84879411496
SN - 1073-5623
VL - 44
SP - 3921
EP - 3933
JO - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
JF - Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
IS - 8
ER -