TY - JOUR
T1 - Kinetics and Equilibrium of Age-Induced Precipitation in Cu-4 At. Pct Ti Binary Alloy
AU - Semboshi, Satoshi
AU - Amano, Shintaro
AU - Fu, Jie
AU - Iwase, Akihiro
AU - Takasugi, Takayuki
N1 - Funding Information:
The authors are grateful to Professor S. Hanada and Prof. N. Masahashi from the Institute for Materials Research (IMR) of Tohoku University, Professor Y. Kaneno and Professor T. Matsui from Osaka Prefecture University, and Dr. A. Sugarawa, Dr. F. Sasaki, and Mr. H. Suda from DOWA METALTECH Co., Ltd. for their useful discussions and comments. The authors also thank Dr. M. Nagasako, Dr. M. Ishikuro, Mr. E. Aoyagi, and Mr. S. Ito from IMR for technical assistance. Financial support was provided by the Japan Society for the Promotion of Science in the framework of the Grant-in-Aid for Scientific Research program (Grant No. 26420663) and by the Japan Copper and Brass Association (2016).
Publisher Copyright:
© 2017, The Minerals, Metals & Materials Society and ASM International.
PY - 2017/3/1
Y1 - 2017/3/1
N2 - Transformation kinetics and phase equilibrium of metastable and stable precipitates in age-hardenable Cu-4 at. pct Ti binary alloy have been investigated by monitoring the microstructural evolution during isothermal aging at temperatures between 693 K (420 °C) and 973 K (700 °C). The microstructure of the supersaturated solid solution evolves in four stages: compositional modulation due to spinodal decomposition, continuous precipitation of the needle-shaped metastable β′-Cu4Ti with a tetragonal structure, discontinuous precipitation of cellular components containing stable β-Cu4Ti lamellae with an orthorhombic structure, and eventually precipitation saturation at equilibrium. In specimens aged below 923 K (650 °C), the stable β-Cu4Ti phase is produced only due to the cellular reaction, whereas it can be also directly obtained from the intergranular needle-shaped β′-Cu4Ti precipitates in specimens aged at 973 K (700 °C). The precipitation kinetics and phase equilibrium observed for the specimens aged between 693 K (420 °C) and 973 K (700 °C) were characterized in accordance with a time–temperature–transformation (TTT) diagram and a Cu-Ti partial phase diagram, which were utilized to determine the alloy microstructure, strength, and electrical conductivity.
AB - Transformation kinetics and phase equilibrium of metastable and stable precipitates in age-hardenable Cu-4 at. pct Ti binary alloy have been investigated by monitoring the microstructural evolution during isothermal aging at temperatures between 693 K (420 °C) and 973 K (700 °C). The microstructure of the supersaturated solid solution evolves in four stages: compositional modulation due to spinodal decomposition, continuous precipitation of the needle-shaped metastable β′-Cu4Ti with a tetragonal structure, discontinuous precipitation of cellular components containing stable β-Cu4Ti lamellae with an orthorhombic structure, and eventually precipitation saturation at equilibrium. In specimens aged below 923 K (650 °C), the stable β-Cu4Ti phase is produced only due to the cellular reaction, whereas it can be also directly obtained from the intergranular needle-shaped β′-Cu4Ti precipitates in specimens aged at 973 K (700 °C). The precipitation kinetics and phase equilibrium observed for the specimens aged between 693 K (420 °C) and 973 K (700 °C) were characterized in accordance with a time–temperature–transformation (TTT) diagram and a Cu-Ti partial phase diagram, which were utilized to determine the alloy microstructure, strength, and electrical conductivity.
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U2 - 10.1007/s11661-016-3949-x
DO - 10.1007/s11661-016-3949-x
M3 - Article
AN - SCOPUS:85009255571
SN - 1073-5623
VL - 48
SP - 1501
EP - 1511
JO - Metallurgical Transactions A (Physical Metallurgy and Materials Science)
JF - Metallurgical Transactions A (Physical Metallurgy and Materials Science)
IS - 3
ER -