Microstructural stability of the cocrfe2ni2 high entropy alloys with additions of cu and mo

New High Entropy Alloys based on the CoCrFeNi 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 1200C. In order to evaluate their thermal stability, aging heat treat...

Descripción completa

Detalles Bibliográficos
Autores: Toda Caraballo, Isaac, Jiménez, José Antonio, Milenkovic, Srdjan, Jiménez-Aguirre, Jorge, San-Martín, David
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/265089
Acceso en línea:http://hdl.handle.net/10261/265089
Access Level:acceso abierto
Palabra clave:High entropy alloys
Alloy design
Thermal treatments
Microstructural characterization
Descripción
Sumario:New High Entropy Alloys based on the CoCrFeNi 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 1200C. In order to evaluate their thermal stability, aging heat treatments at 500, 700, and 900C 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.