TY - JOUR
T1 - Accelerating heterogeneous nucleation to increase hardness and electrical conductivity by deformation prior to ageing for Cu-4 at.% Ti alloy
AU - Han, Seung Zeon
AU - Semboshi, Satoshi
AU - Ahn, Jee Hyuk
AU - Choi, Eun Ae
AU - Cho, Minah
AU - Kadoi, Yusuke
AU - Kim, Kwangho
AU - Lee, Jehyun
N1 - Funding Information:
This work was supported principally by Global Frontier R&D Program (2013M3A6B1078874) on Global Frontier Hybrid Interface Materials R&D Center funded by the Ministry of Science, ICT, and Future Planning and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) [No. 2018R1A5A6075959], and the Fundamental Research Program (POC3360) of the Korea Institute of Materials Science.
Publisher Copyright:
© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.
PY - 2019/8/3
Y1 - 2019/8/3
N2 - Deformation bands, especially shear bands were intentionally formed in supersaturated Cu-4 at.% Ti alloy by groove-rolling with 75% area reduction. Cold deformation prior to the ageing process changed the precipitation behaviour of the alloy. The deformed structure with shear bands was maintained, without showing recovery and recrystallisation, even after prolonged ageing at 450°C for more than one day. The thermally stable shear bands act as nucleation initiation sites and prevent the expansion of discontinuous cellular precipitates. The hardness reached a value of 305 Hv and an electrical conductivity of 15% IACS (IACS = International Annealed Copper Standard. 100% IACS is defined as the conductivity corresponding to a volume resistivity at 20°C of 17.241 nΩ), compared to 283 Hv and 13% IACS for conventional solid-solutioned and peak-hardened alloy. In addition, the ageing time to reach the highest hardness was shortened from 720 to 180 min at 450°C.
AB - Deformation bands, especially shear bands were intentionally formed in supersaturated Cu-4 at.% Ti alloy by groove-rolling with 75% area reduction. Cold deformation prior to the ageing process changed the precipitation behaviour of the alloy. The deformed structure with shear bands was maintained, without showing recovery and recrystallisation, even after prolonged ageing at 450°C for more than one day. The thermally stable shear bands act as nucleation initiation sites and prevent the expansion of discontinuous cellular precipitates. The hardness reached a value of 305 Hv and an electrical conductivity of 15% IACS (IACS = International Annealed Copper Standard. 100% IACS is defined as the conductivity corresponding to a volume resistivity at 20°C of 17.241 nΩ), compared to 283 Hv and 13% IACS for conventional solid-solutioned and peak-hardened alloy. In addition, the ageing time to reach the highest hardness was shortened from 720 to 180 min at 450°C.
KW - Copper-titanium alloys
KW - discontinuous precipitation
KW - electrical conductivity
KW - heterogeneous nucleation
KW - shear band
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U2 - 10.1080/09500839.2019.1670879
DO - 10.1080/09500839.2019.1670879
M3 - Article
AN - SCOPUS:85073608882
SN - 0950-0839
VL - 99
SP - 275
EP - 283
JO - Philosophical Magazine Letters
JF - Philosophical Magazine Letters
IS - 8
ER -