| About this Abstract |
| Meeting |
Materials Science & Technology 2020
|
| Symposium
|
Microstructure and Physical Property Optimization in High Entropy Alloys
|
| Presentation Title |
On the Low Cycle Fatigue Response of CoCrNiFeMn High Entropy Alloy with Ultra-fine Grain Structure |
| Author(s) |
Sezer Picak, Thomas Wegener, Seyedvahid Sajjadifar, Julia Richter, César Sobrero, Thomas Niendorf, Ibrahim Karaman |
| On-Site Speaker (Planned) |
Sezer Picak |
| Abstract Scope |
High Entropy Alloys (HEAs) such as CoCrFeMnNi are a new class of multi-component metallic materials. However, their relatively low yield strength level is a major drawback. In the present work, Equal Channel Angular Pressing (ECAP) was employed to improve the initial yield strength level of CoCrFeMnNi HEA. In light of envisaged fields in engineering, the HEA was also studied under cyclic loading as this might show different microstructural evolution as compared to quasi-static monotonic loading. To allow for meaningful comparison, both strain-controlled low cycle fatigue tests under fully reversed push-pull loading (R=-1) and quasi-static (tensile and compression) tests were conducted at room temperature. Very high tensile and compressive yield strength levels (1.1 GPa) and superior fatigue life were obtained after ECAP processing due to grain-refinement and high defect densities. Finally, the formation of cell structure in these kinds of alloys is, for the first time, rationalized by the Copley-Kear effect. |