Corrosion Behavior of Ultrafine-Grained CoCrFeMnNi High-Entropy Alloys Fabricated by High-Pressure Torsion

Materials

Hiroyuki Miyamoto¹  Motohiro Yuasa¹  Haruka Shimizu²  Kaveh Edalati³ 

[1] Department of Mechanical Engineering, Doshisha University, Kyotanabe 610-0394, Japan;Graduate School of Mechanical Engineering, Doshisha University, Kyotanabe 610-0394, Japan;WPI, International Institute for Carbon-Neutral Research (WPI-I2CNER), Kyushu University, Fukuoka 819-0395, Japan;

关键词: severe plastic deformation;    high-pressure torsion (HPT);    high-entropy alloys;    ultrafine-grained materials (UFG);    nanocrystalline materials;    passivation;   

DOI  :  10.3390/ma15031007

来源: DOAJ

【 摘 要 】

The influence of the nanocrystalline structure produced by severe plastic deformation (SPD) on the corrosion behavior of CoCrFeMnNi alloys with Cr contents ranging from 0 to 20 at.% was investigated in aqueous 0.5 M H₂SO₄ and 3.5% NaCl solutions. The resistance to general corrosion and pitting became higher in both the solutions, with higher passivation capability observed with increasing Cr content, and it is believed that the high corrosion resistance of CoCrFeMnNi alloys can be attributed to the incorporation of the Cr element. However, the impact of the nanocrystalline structure produced by SPD on the corrosion behavior was negligibly small. This is inconsistent with reports on nanocrystalline binary Fe–Cr alloys and stainless steels processed by SPD, where grain refinement by SPD results in higher corrosion resistance. The small change in the corrosion behavior with respect to grain refinement is discussed, based on the passivation process of Fe–Cr alloys and on the influence of the core effects of HEAs on the passivation process.

【 授权许可】

Unknown