The Effect of Increasing Nickel Content on the Microstructure, Hardness, and Corrosion Resistance of the CuFeTiZrNi x High-Entropy Alloys

Po-Cheng Kuo; Sin-Yi Chen; William Yu; Ryo Okumura; Satoshi Iikubo; Andromeda Dwi Laksono; Yee-Wen Yen; Alberto S Pasana

doi:10.3390/ma15093098

The Effect of Increasing Nickel Content on the Microstructure, Hardness, and Corrosion Resistance of the CuFeTiZrNi _x High-Entropy Alloys

Materials (Basel). 2022 Apr 25;15(9):3098. doi: 10.3390/ma15093098.

Authors

Po-Cheng Kuo¹, Sin-Yi Chen¹, William Yu¹, Ryo Okumura², Satoshi Iikubo^{2

3}, Andromeda Dwi Laksono¹, Yee-Wen Yen¹, Alberto S Pasana⁴

Affiliations

¹ Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei 10672, Taiwan.
² Kyushu Institute of Technology, Graduate School of Life Science and Systems Engineering, Kitakyushu 808-0196, Japan.
³ Department of Advanced Materials Science and Engineering, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan.
⁴ School of Engineering, University of San Carlos (USC), Cebu City 6000, Philippines.

Abstract

In recent years, high-entropy alloys (HEAs) that contain fine grains of intermetallic compounds (IMCs) have gained increasing attention as they have been shown to exhibit both high mechanical strength and strong corrosion resistance. One such class of HEAs is that of CuFeTiZrNi alloys. In this study, we have investigated the effect of increasing Ni content on the microstructure, hardness, and corrosion resistance of the CuFeTiZrNi_x alloys (where x = 0.1, 0.3, 0.5, 0.8, 1.0 in a molar ratio). The alloys used in this study were prepared in an arc melting furnace and then annealed at 900 °C. First-principles calculations of the bulk modulus were also performed for each alloy. The results revealed that increasing the Ni content had several effects. Firstly, the microstructure of the CuFeTiZrNi_x alloys changed from B2_BCC and Laves_C14 in the CuFeTiZrNi_0.1 and CuFeTiZrNi_0.3 alloys to FCC, B2_BCC, and Laves_C14 in the CuFeTiZrNi_0.5 alloys; and to FCC, B2_BCC, Cu₅₁Zr₁₄, and Laves_C14 in the CuFeTiZrNi_0.8 and CuFeTiZrNi_1.0 alloys. Secondly, IMCs arising from a combination of the refractory elements (Ti and Zr) and atomic size differences were found in the interdendritic region. Thirdly, as the Ni content in the CuFeTiZrNi_x alloys increased, the hardness decreased, but the corrosion resistance increased.

Keywords: CuFeTiZrNix alloys; corrosion resistance; first-principles calculations; hardness; microstructure.

Abstract

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