Study of phase transformations under extreme conditions of multi-principal element alloys based on CoCrNi

• Grant number: 24/01818-1
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2024
• End date: June 30, 2026
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Agreement: CNPq
• Principal Investigator: Francisco Gil Coury
• Grantee: Francisco Gil Coury
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 22/02770-7 - Integrated Computational Materials Engineering ICME: applied to modeling, production, characterization and testing high entropy alloys, AP.PNGP.PI
• Associated scholarship(s): 24/17093-6 - The effect of short-range ordering on the stacking fault energy of CoCrNi-based multiprincipal element alloys, BP.IC; 24/11008-7 - Young Investigator Fixed Grant - Study of Phase Transformations under Extreme Conditions of CoCrNi-based High Entropy Alloys, BP.JD

Abstract

High/medium entropy alloys (HEAs/MEAs), or multi-principal element alloys (MPEAs), are emerging materials that are gaining notable interest. Several MPEAs combine high strength, ductility, fracture toughness, and resistance to oxidation, corrosion, and radiation. One of the most notable alloys in this regard is the CoCrNi alloy. This makes MPEAs suitable for sectors such as biomedical, energy, and aerospace. A key point for these materials is the martensitic transformation, responsible for many of their superior mechanical properties. However, a complete thermodynamic description of this transformation is not well understood. Our study evaluates how the variation in composition and temperature, above and below room temperature (cryogenic), affects the phase transformation of CoCrNi-based MPEAs. An important complement to this project will be the use of in situ synchrotron X-ray diffraction measurements at high pressures. These results will expand the current knowledge of phase transformation-induced plasticity (TRIP). The second objective of the research is to understand how short-range chemical ordering can affect stacking fault energy and possibly influence the mode of plastic deformation at cryogenic temperatures and under high deformation rates. (AU)