echanical properties and yield strength modeling of a medium entropy alloy containing L1(2) precipitate

Author(s)

Santana, Diego de Araujo ^[1] ; Kiminami, Claudio Shyinti ^[2] ; Coury, Francisco Gil ^[2]

Affiliation

^[1] Univ Fed Sao Carlos, Grad Program Mat Sci & Engn, Rodovia Washington Luis, Km 235 SP 310, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Mat Engn, Rodovia Washington Luis, Km 235 SP 310, BR-13565905 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Journal of Alloys and Compounds; v. 898, MAR 25 2022.
• Web of Science Citations: 0

Abstract

Medium/High Entropy Alloys (M/HEAs) exit over immense compositional fields, which represent a challenging opportunity for the development of alloys with optimized properties. To realize their potential, we need to be able to predict properties of interest from different compositions effectively. Precipitation strengthened alloys are of wide interest, but their yield strength modeling is not simple because many factors as precipitate type, size, fraction, and composition play important roles. The Cr29.7CO29.7 Ni35.4Al4.0Ti1.2 (at%) alloy was designed to have a highly concentrated Cr-Co-Ni face centered cubic matrix with L1(2) precipitates. In the present work, this alloy was aged at 850 degrees C for times up to 166 h and had its yield strength measured in the different aging conditions through tensile tests. A recently developed model to calculate the solid solution contribution in FCC multi-principal element alloys was coupled with classical grain-boundary strengthening and precipitation hardening models to predict the yield strength of the studied alloy. We show that the different strengthening contributions can be modeled independently with satisfactory accuracy. The results can be easily extrapolated to other alloys of the Cr-Co-Ni-Al-Ti system. An empirical relationship to estimate the room temperature lattice parameter of FCC alloys is also proposed. A promising route to explore the vast compositional space of M/HEA and design new precipitation hardening alloys with optimized mechanical properties is suggested. (C) 2021 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 21/04302-8 - Microstructural refining mechanisms and mechanical properties optimization in high toughness multi-principal element alloys
• Grantee: Francisco Gil Coury
• Support Opportunities: Regular Research Grants
• FAPESP's process: 18/26390-3 - Design, production and characterization of high mechanical strength precipitation-hardened high entropy alloys
• Grantee: Diego de Araujo Santana
• Support Opportunities: Scholarships in Brazil - Doctorate