Effect of Zn Addition on Phase Evolution in AlCrFeCoNiZn High–Entropy Alloy
[1];
[2];
[2];
- Indian Institute of Technology Ropar, Punjab (India); Seoul National University (Korea, Republic of)
- Indian Institute of Technology Ropar, Punjab (India)
- Indian Institute of Technology (BHU), Uttar Pradesh (India); Indian Institute of Technology Bhilai Durg, Chhatishgarh (India)
- Ames Laboratory (AMES), Ames, IA (United States)
- Indian Institute of Technology Madras Chennai, Tamil Nadu (India)
- Ames Laboratory (AMES), Ames, IA (United States); Iowa State University, Ames, IA (United States)
- Indian Institute of Technology (BHU), Uttar Pradesh (India)
The addition of Zn to AlCrFeCoNi high-entropy alloy (HEA) poses intriguing questions as to how it would affect phase evolution. Herein, the phase evolution in AlCrFeCoNiZn is studied using a combination of experimental techniques (X-ray diffraction, scanning electron microscopy, energy-dispersive spectroscopy, and differential scanning calorimetry) and computational (density-functional theory [DFT], calculation of phase diagrams, and machine-learning) methods. Mechanically alloyed and spark-plasma-sintered AlCrFeCoNiZn assumes a metastable single-phase, body-centered-cubic (BCC) structure that undergoes diffusion-controlled phase separation upon subsequent heat treatment to form separate (Al, Cr)-rich, (Fe, Co)-rich, and (Zn, Ni)-rich phases. The formation of (Al, Cr)-rich phase, not reported previously in AlCrFeCoNi-based HEAs, is attributed to strong clustering tendency of Cr–Zn and Cr–Ni pairs, combined with the strong ordering of Zn–Ni pair, driving out Cr that in turn combines with Al to form a (Al, Cr)-rich phase. In the DFT results, the formation of thermodynamically stable L12 phase is shown wherein Cr–Fe–Zn [Al–Ni-Co] preferably occupy1a (000) [3c (0 ½ ½)] positions. Furthermore, the sluggish diffusional transformation to L12 phase from BCC precursors is attributed to the small stacking-fault energy of AlCrFeCoNiZn. The equilibrated HEA exhibits a high microhardness of 8.24 GPa with an elastic modulus of 184 GPa.
- Research Organization:
- Ames Laboratory (AMES), Ames, IA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
- Grant/Contract Number:
- AC02-07CH11358
- OSTI ID:
- 2448471
- Report Number(s):
- IS-J--11,444
- Journal Information:
- Advanced Engineering Materials, Journal Name: Advanced Engineering Materials Journal Issue: 6 Vol. 27; ISSN 1438-1656
- Publisher:
- WileyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Experimental and Computational Investigation of High Entropy Alloys for Elevated-Temperature Applications
Revisit the VEC rule in high entropy alloys (HEAs) with high-throughput CALPHAD approach and its applications for material design-A case study with Al–Co–Cr–Fe–Ni system