About this Abstract |
Meeting |
2nd World Congress on High Entropy Alloys (HEA 2021)
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Symposium
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2nd World Congress on High Entropy Alloys (HEA 2021)
|
Presentation Title |
Tuning Chemical Ordering in the Concentrated Solid Solution of High Entropy Alloys |
Author(s) |
Sriswaroop Dasari, Abhishek Sharma, Bharat Gwalani, Rajarshi Banerjee |
On-Site Speaker (Planned) |
Sriswaroop Dasari |
Abstract Scope |
While single-phase solid solution based high entropy alloys (HEAs) have attracted enormous attention in the last fifteen years, a controversy surrounds the fundamental question: How random are these complex concentrated solid solutions? Recent computational and experimental studies often have opposing viewpoints regarding the presence of local short-range order (SRO), or “clustered ordering” in these alloys. Using thermodynamic binary mixing enthalpies of constituent pairs, the present study demonstrates how the degree of chemical ordering can be systematically tuned within these concentrated solid solutions. Starting with a near ideal equiatomic CoFeNi solid solution, additions of Al and Ti promote local ordering, as evidenced by detailed electron diffraction coupled with atom probe tomography. Consequently, the tensile yield strength can be increased from 190 MPa (CoFeNi) to 280 MPa (Al0.25CoFeNi) to 450 MPa (Al0.3CoFeNi), finally to 800 MPa (Al0.3Ti0.2CoFeNi), more than a four-fold increase, with a progressive increase in the degree of local ordering. |
Proceedings Inclusion? |
Undecided |