The effect of short-range ordering on the stacking fault energy of CoCrNi-based multiprincipal element alloys

• Grant number: 24/17093-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: June 30, 2025
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Angelo Fernandes Andreoli
• Grantee: Maria Fernanda Ladeira Valverde
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 24/01818-1 - Study of phase transformations under extreme conditions of multi-principal element alloys based on CoCrNi, AP.R

Abstract

Chemical short-range order (CSRO) has recently attracted significant research efforts in multi-principal element alloys (MPEAs). Contrary to what was initially believed, which is that the entropic effect would stabilize random solid solutions, especially at higher temperatures, the formation of CSRO appears to be a common feature of several MPEAs. Less understood is how CSRO can affect their properties. There is an ongoing dispute on whether CSRO affects their mechanical behavior, and a conclusion that local chemical ordering may influence the stacking fault energy (SFE), and consequently, their mechanical performance, remains unexplored. This project aims to provide answers to these questions. Co40Cr40Ni20 and Co20Cr45Ni35 (at. %) MPEAs will be investigated. A comparison of these alloys under two conditions, recrystallized and aged to induce CSRO, will be carried out. The mechanical properties under ambient and cryogenic temperatures will be evaluated, and a correlation between CSRO and a possible change in SFE expressed as the degree of transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP) effects, will be analyzed.