High-entropy alloy strengthened by in situ formation of entropy-stabilized nano-dispersoids

• Published in: Scientific reports Vol. 8; no. 1; pp. 14085 - 9
• Main Authors: Gwalani, Bharat, Pohan, Rizaldy M., Lee, Junho, Lee, Bin, Banerjee, Rajarshi, Ryu, Ho Jin, Hong, Soon Hyung
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20-09-2018; Nature Publishing Group
• Subjects: 639/301/1023/303; 639/301/357/537; Entropy; Humanities and Social Sciences; multidisciplinary; Plasma sintering; Science; Science (multidisciplinary); Transmission electron microscopy; Atom Probe Tomography (APT); Spark Plasma Sintering (SPS); High-entropy Alloys (HEAs); CoCrFeMnNi HEA; Compositional Complexity
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-32552-6

A significant increase in compressive yield strength of the Al
0.3
CoCrFeMnNi high-entropy alloy (HEA) from 979 MPa to 1759 MPa was observed upon the introduction of 3 vol.% Y
2
O
3
. The HEAs were processed using spark plasma sintering of mechanically alloyed powders. Transmission electron microscopy and atom probe tomography confirmed the presence of compositionally complex nano-dispersoids in the Y
2
O
3
-added HEA. The significant increase in strength can be attributed to the nano-dispersoid strengthening coupled with grain refinement. Therefore, the
in-situ
formation of the compositionally complex nanoscale dispersoids during the alloy processing could be a novel approach to create entropy-stabilized oxide particles in strengthening of HEAs.