Effect of Adding Minor Cu Amounts on Stability of Constituent Phases in Al_xCrFeMnNi High Entropy Alloy Microstructure

Abstract:

A family of Al_xCu_yCrFeMnNi (x=0, 0.15, 0.3, 0.6, 0.9 and y=0, 0.07, 0.14) high entropy alloys (HEA) were arc cast and then heat treated for 24h at 1100֯C-1150֯C followed by water quench. The microstructure of low Al alloys (Al₀Cu_x and Al_0.15Cu_x) consisted of FCC and BCC phases. Al_0.3Cu_x showed an additional ordered precipitate phase. High Al alloys (Al_0.6Cu_x and Al_0.9Cu_x) consisted of two BCC phases rich in Cr-Fe and Ni-Al. In the present study, the phases formed in the microstructures were evaluated in light of valence electron concentration (VEC), Hume-Rothery (H-R) and degree of partitioning. Although VEC successfully predicts the impact of Al and Cu on the trend of FCC-BCC phase formation, the parameter does not accurately predict the structure of high Al alloys. A good agreement was observed between H-R rules prediction and the experiments which might be ascribed to the high temperature equilibrium phases developed by the heat treatment. As per these criteria, increasing Cu (up to 3at.%) and decreasing Al promote formation of solid solution phases. Adding minor amounts of Cu avoids the Cu partitioning that besets high Cu HEAs.

• Periodical: Solid State Phenomena (Volume 357)
• Pages: 19-25
• DOI: https://doi.org/10.4028/p-HjgE0D
• Online since: June 2024
• Authors: Mohammad Navazani*, Sitarama Raju Kada, Daniel Fabijanic, Matthew R. Barnett
• Keywords: Co-Free HEA, Degree of Partitioning, High Entropy Alloys, Hume-Rothery Rules, Low Cu HEA, Valence Electron Concentration (VEC)

References

[1] Miracle, D.B. and O.N. Senkov, 2017, Acta Materialia. 122: pp.448-511.

[2] Hyun, J.I., K.H. Kong, K.C. Kim, W.T. Kim, and D.H. Kim, 2015, Applied Microscopy. 45(1): pp.9-15.

[3] Rao, Z., X. Wang, Q. Wang, T. Liu, X. Chen, L. Wang, and X. Hui, 2017, Advanced Engineering Materials. 19(5): p.1600726.

[4] Hume-Rothery, W., 1952.

[5] Hume-Rothery, W. and H.M. Powell, 1935, Zeitschrift für Kristallographie-Crystalline Materials. 91(1-6): pp.23-47.

DOI: 10.1524/zkri.1935.91.1.23

[6] Hume-Rothery, W., 1969, Indian Journal of Physics. 11: pp.74-74.

[7] Wu, P.H., N. Liu, W. Yang, Z.X. Zhu, Y.P. Lu, and X.J. Wang, 2015, Materials Science and Engineering: A. 642: pp.142-149.

[8] Ye, Y.F., Q. Wang, J. Lu, C.T. Liu, and Y. Yang, 2016, Materials Today. 19(6): pp.349-362.

[9] Wang, W.L., L. Hu, S.B. Luo, L.J. Meng, D.L. Geng, and B. Wei, 2016, Intermetallics. 77: pp.41-45.

[10] Li, C., Y. Xue, M. Hua, T. Cao, L. Ma, and L. Wang, 2016, Materials & Design. 90: pp.601-609.

[11] Xian, X., L. Lin, Z. Zhong, C. Zhang, C. Chen, K. Song, J. Cheng, and Y. Wu, 2018, Materials Science and Engineering: A. 713: pp.134-140.

[12] Ren, B., Z.X. Liu, D.M. Li, L. Shi, B. Cai, and M.X. Wang, 2010, Journal of Alloys and Compounds. 493(1): pp.148-153.

[13] Ren, B., Z.X. Liu, D.M. Li, L. Shi, B. Cai, and M.X. Wang, 2012, Materials and Corrosion. 63(9): pp.828-834.

[14] Navazani, M., S.R. Kada, D. Fabijanic, and M. Barnett, 2024, Intermetallics. 164: p.108100.

DOI: 10.1016/j.intermet.2023.108100

[15] Takeuchi, A. and A. Inoue, 2005, MATERIALS TRANSACTIONS. 46(12): pp.2817-2829.

[16] Chen, H.-Y., C.-W. Tsai, C.-C. Tung, J.-W. Yeh, T.-T. Shun, C.-C. Yang, and P.-H. Lee, 2006, European Journal of Control - EUR J CONTROL. 31: pp.685-698.

[17] Zhang, L.J., K. Guo, H. Tang, M.D. Zhang, J.T. Fan, P. Cui, Y.M. Ma, P.F. Yu, and G. Li, 2019, Materials Science and Engineering: A. 757: pp.160-171.

[18] Börnsen, N., G. Bester, B. Meyer, and M. Fähnle, 2000, Journal of Alloys and Compounds. 308(1): pp.1-14.