Influence of heat treatment on microstructure, mechanical behavior, and soft magnetic properties in an fcc-based Fe29Co28Ni29Cu7Ti7 high-entropy alloy

• Published in: Journal of materials research Vol. 33; no. 15; pp. 2214 - 2222
• Main Authors: Fu, Zhiqiang, MacDonald, Benjamin E., Monson, Todd C., Zheng, Baolong, Chen, Weiping, Lavernia, Enrique J.
• Format: Journal Article
• Language: English
• Published: New York, USA Cambridge University Press 13-08-2018; Springer International Publishing; Springer Nature B.V
• Subjects: Alloys; Applied and Technical Physics; Biomaterials; Casting alloys; Coercivity; Crystal structure; Elongation; Entropy; Grain boundaries; Grain growth; Heat; Heat treating; Heat treatment; High entropy alloys; Homogenization; Inorganic Chemistry; Magnetic properties; Magnetic saturation; Magnetism; Materials Engineering; Materials research; Materials Science; Mechanical properties; Microstructure; MSAT; Nanotechnology; Precipitates; Raw materials; Solids; Ultimate tensile strength; Yield strength; Yield stress; soft magnetic properties; microstructure; heat treatment; high-entropy alloys
• ISSN: 0884-2914; 2044-5326
• DOI: 10.1557/jmr.2018.161

The influence of heat treatment (homogenization) on the microstructure, mechanical behavior, and soft magnetic properties of a face-centered cubic (fcc)-based high-entropy alloy (HEA), Fe29Co28Ni29Cu7Ti7, fabricated by casting, was investigated in detail. The as-cast Fe29Co28Ni29Cu7Ti7 HEA was composed of a primary fcc phase containing coherent dispersed L12 nanoprecipitates and trace amounts of a needle-like phase. The tensile yield strength (σ0.2), ultimate strength, and total elongation of the as-cast alloy are 917 MPa, 1060 MPa, and 1.8%, respectively. Following homogenization, the alloy having a single fcc phase shows a decrease of ∼ 55% in yield strength and a decrease of ∼ 36% in ultimate strength; however, the total elongation is increased from 1.8 to 52%. Saturation magnetization (Msat) is decreased from 111.54 to 110.34 Am2/kg, by contrast, coercivity (Hc) is increased from 266.65 to 966.89 A/m. The dissolution of precipitates and grain growth are mainly responsible for the changes in magnetic properties and mechanical behavior.