Microstructural Stability of the CoCrFe2Ni2 High Entropy Alloys with Additions of Cu and Mo

Metals

Srdjan Milenkovic¹  David San-Martín²  Jorge Jimenez-Aguirre²  Isaac Toda-Caraballo²  Jose Antonio Jiménez² 

[1] IMDEA Materials Institute, Tecnogetafe, Calle Eric Kandel, 2, 28906 Getafe, Spain;Materalia Group, National Center for Metallurgical Research (CENIM-CSIC), Avda. Gregorio del Amo 8, 28040 Madrid, Spain;

关键词: high entropy alloys;    alloy design;    thermal treatments;    microstructural characterization;   

DOI  :  10.3390/met11121994

来源: DOAJ

【 摘 要 】

New High Entropy Alloys based on the CoCrFe₂Ni₂ system have been developed by adding up to 10 at. % of Cu, Mo, and Cu + Mo in different amounts. These alloys showed a single face-centred cubic (FCC) structure after homogenization at 1200 °C. In order to evaluate their thermal stability, aging heat treatments at 500, 700, and 900 °C for 8 h were applied to study the possible precipitation phenomena. In the alloys where only Cu or Mo was added, we found the precipitation of an FCC Cu-rich phase or the µ phase rich in Mo, respectively, in agreement with some of the results previously shown in the literature. Nevertheless, we have observed that when both elements are present, Cu precipitation does not occur, and the formation of the Mo-rich phase is inhibited (or delayed). This is a surprising result as Cu and Mo have a positive enthalpy of mixing, being immiscible in a binary system, while added together they improve the stability of this system and maintain a single FCC crystal structure from medium to high temperatures

【 授权许可】

Unknown