About this Abstract |
Meeting |
MS&T21: Materials Science & Technology
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Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond II
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Presentation Title |
Discontinuous Precipitation Leading to Nano-rod Intermetallic Precipitates in High Entropy Alloys Results in an Excellent Strength-ductility Combination |
Author(s) |
Sriswaroop Dasari, Abhishek Sharma, Bharat Gwalani, Yao-Jen Chang, Abhinav Jagetia, Vishal Soni, Stephane Gorsse, An-Chou Yeh, Rajarshi Banerjee |
On-Site Speaker (Planned) |
Sriswaroop Dasari |
Abstract Scope |
The phenomenon of discontinuous precipitation (DP) leading to the formation of nano-rod FCC (γ) + L12 (γ’) colonies, has been typically considered deleterious for mechanical properties. However, the present study shows clear evidence that substantially large fractions of FCC + nano-rod L12 microstructure within thermo-mechanically processed high entropy alloys (HEA) or complex concentrated alloys (CCA) of compositions, Al0.2Ti0.3Co1.5CrFeNi1.5 and Al0.3Ti0.2Co0.7CrFeNi1.7, formed via recrystallization coupled with discontinuous precipitation, can lead to excellent room temperature strength and ductility combinations. Further, the extent of thermomechanical processing can be engineered to modify the phase transformation pathway from homogenous L12 precipitation to discontinuous L12 precipitation in the same HEA. The predominantly FCC + nano-rod L12 microstructures in these alloys exhibit yield stresses upto ~1.6 GPa, with good tensile ductility of ~15%, making them some of the best combinations of room temperature tensile properties for FCC-based HEAs, that have been reported to date. |