Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5459240 | Journal of Alloys and Compounds | 2017 | 39 Pages |
Abstract
An equiatomic CoCrFeMnNi High-Entropy Alloy (HEA) produced by arc melting was processed by High-Pressure Torsion (HPT). The evolution of the microstructure during HPT was investigated after ¼, ½, 1 and 2 turns using electron backscatter diffraction and transmission electron microscopy. The spatial distribution of constituents was studied by energy-dispersive X-ray spectroscopy. The dislocation density and the twin-fault probability in the HPT-processed samples were determined by X-ray line profiles analysis. It was found that the grain size was gradually refined from â¼60 μm to â¼30 nm while the dislocation density and the twin-fault probability increased to very high values of about 194 Ã 1014 mâ2 and 2.7%, respectively, at the periphery of the disk processed for 2 turns. The hardness evolution was measured as a function of the distance from the center of the HPT-processed disks. After 2 turns of HPT, the microhardness increased from â¼1440 MPa to â¼5380 MPa at the disk periphery where the highest straining is achieved. The yield strength was estimated as one-third of the hardness and correlated to the microstructure.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Anita Heczel, Megumi Kawasaki, János L. Lábár, Jae-il Jang, Terence G. Langdon, JenÅ Gubicza,