TY - JOUR
T1 - Accelerated design of novel W-free high-strength Co-base superalloys with extremely wide γ/γʹ region by machine learning and CALPHAD methods
AU - Ruan, Jingjing
AU - Xu, Weiwei
AU - Yang, Tao
AU - Yu, Jinxin
AU - Yang, Shuiyuan
AU - Luan, Junhua
AU - Omori, Toshihiro
AU - Wang, Cuiping
AU - Kainuma, Ryosuke
AU - Ishida, Kiyohito
AU - Liu, Chain Tsuan
AU - Liu, Xingjun
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (Grant No. 51831007 ), National Key R&D Program of China ( 2017YFB0702901 ) and Key-area Research, and Development Program of GuangDong Province (No. 2019B010943001). The first-principles calculations were performed under the financial support from the National Natural Science Foundation of China (Grant No. 51601161 ). The APT research was supported by the Collaborative Research Fund (CityU C1027-14E) from the Research Grant Council (RGC) of Hong Kong. J.J. Ruan performed all the experiments including TEM, EPMA, SEM, compression tests, etc., and wrote the paper. C.P. Wang and X.J. Liu discussed the details of the concepts of this study with J.J. Ruan and revised the manuscript. W.W. Xu performed the first-principles calculations. C.T. Liu, T. Yang and J.H. Luan provided the help in performing APT experiments and analyzing the related data. J.X. Yu performed the machine learning for this work. S.Y. Yang revised the manuscript. K. Ishida, R. Kainuma and T. Omori discussed the details of the experiments in this work, and provided the help in revising the manuscript, and operating the TEM, EPMA and DSC, etc. We would like to thank Editage ( www.editage.cn ) for English language editing.
Funding Information:
This work was supported by the National Natural Science Foundation of China (Grant No. 51831007), National Key R&D Program of China (2017YFB0702901) and Key-area Research, and Development Program of GuangDong Province (No. 2019B010943001). The first-principles calculations were performed under the financial support from the National Natural Science Foundation of China (Grant No. 51601161). The APT research was supported by the Collaborative Research Fund (CityU C1027-14E) from the Research Grant Council (RGC) of Hong Kong. J.J. Ruan performed all the experiments including TEM, EPMA, SEM, compression tests, etc. and wrote the paper. C.P. Wang and X.J. Liu discussed the details of the concepts of this study with J.J. Ruan and revised the manuscript. W.W. Xu performed the first-principles calculations. C.T. Liu, T. Yang and J.H. Luan provided the help in performing APT experiments and analyzing the related data. J.X. Yu performed the machine learning for this work. S.Y. Yang revised the manuscript. K. Ishida, R. Kainuma and T. Omori discussed the details of the experiments in this work, and provided the help in revising the manuscript, and operating the TEM, EPMA and DSC, etc. We would like to thank Editage (www.editage.cn) for English language editing.
Publisher Copyright:
© 2020 Acta Materialia Inc.
PY - 2020/3
Y1 - 2020/3
N2 - Since half a century ago, researchers have continuously focused on developing γʹ-strengthened Co-base superalloys to achieve an increased power and efficiency; these alloys can supposedly operate at higher temperatures than Ni-base superalloys. However, the yielded results have failed to meet the expectations. Herein, we successfully design novel W-free Co-V-Ta-base alloys by employing machine learning algorithm and CALPHAD methods, which exhibit low mass density (8.67–8.86 g/cm3), an extremely wide γ/γʹ region, a high γʹ solvus temperature (up to 1044 °C), and a high strength. The atom probe tomography results show that titanium is an extremely strong γʹ-former; therefore, it is expected to improve the thermodynamic stability of the γʹ phase. Furthermore, besides the very high tensile strength (18.7 GPa) of γʹ phase, indicated by first-principles calculations, the strength of Ti-incorporated alloy is higher than that of γʹ-strengthened Co-base superalloys; especially, the reported strength value is higher than that of the well-known Co-9Al-9 W alloy by approximately 322 MPa at 750 °C, which is comparable to that of a few commercial Ni-base superalloys. Therefore, the possibility of the Co-V-Ta-base system being a candidate for developing novel Co-base superalloys is strongly suggested in this study.
AB - Since half a century ago, researchers have continuously focused on developing γʹ-strengthened Co-base superalloys to achieve an increased power and efficiency; these alloys can supposedly operate at higher temperatures than Ni-base superalloys. However, the yielded results have failed to meet the expectations. Herein, we successfully design novel W-free Co-V-Ta-base alloys by employing machine learning algorithm and CALPHAD methods, which exhibit low mass density (8.67–8.86 g/cm3), an extremely wide γ/γʹ region, a high γʹ solvus temperature (up to 1044 °C), and a high strength. The atom probe tomography results show that titanium is an extremely strong γʹ-former; therefore, it is expected to improve the thermodynamic stability of the γʹ phase. Furthermore, besides the very high tensile strength (18.7 GPa) of γʹ phase, indicated by first-principles calculations, the strength of Ti-incorporated alloy is higher than that of γʹ-strengthened Co-base superalloys; especially, the reported strength value is higher than that of the well-known Co-9Al-9 W alloy by approximately 322 MPa at 750 °C, which is comparable to that of a few commercial Ni-base superalloys. Therefore, the possibility of the Co-V-Ta-base system being a candidate for developing novel Co-base superalloys is strongly suggested in this study.
KW - Atom probe tomography (APT)
KW - Cobalt-base superalloys
KW - Grain-boundary segregation-induced phase transformation
KW - L12 compound
KW - Machine learning
KW - Mechanical property
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U2 - 10.1016/j.actamat.2020.01.004
DO - 10.1016/j.actamat.2020.01.004
M3 - Article
AN - SCOPUS:85078208453
VL - 186
SP - 425
EP - 433
JO - Acta Materialia
JF - Acta Materialia
SN - 1359-6454
ER -