Effect of C and N Additions on Stacking Fault Energy and TRIP Deformation Mechanism of the Cr40Co40Ni20 Multi-Principal Element Alloy

• Grant number: 23/16311-7
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: April 01, 2024
• End date: September 30, 2024
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Claudio Shyinti Kiminami
• Grantee: Gustavo Bertoli
• Supervisor: Michael Joseph Kaufman
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Institution abroad: Colorado School of Mines, United States
• Associated to the scholarship: 21/05408-4 - Effect of C, N and B addition on the phase equilibrium and mechanical behavior of the Cr40Co40Ni20 multi-principal element alloy, BP.DR

Abstract

Medium/high entropy, Multiprincipal element alloys (MPEAs) have significantly increased the number of potential compositions of metallic alloys to unprecedented levels. In addition to discovering new compositions of interest, optimizing the most promising MPEAs is equally critical. The Cr40Co40Ni20 MPEA stands out by showing high mechanical strengthening via grain refining, and high work hardening capacity resulting from the strain-induced HCP phase formation (TRIP effect). An important optimization route is the use of interstitial elements such as C and N as microstructural refiners, which should be especially advantageous in this MPEA. The student's doctoral project is focused on studying the effect of these interstitial elements on grain refining, phase equilibria, and mechanical properties of the Cr40Co40Ni20 MPEA. The student has also been developing a work about the influence of grain refinement on deformation mechanisms, that is, on the critical stress for activation and evolution of the TRIP effect. C and N additions should alter the stacking fault energy (SFE) and consequently alter an important characteristic of the studied alloy, its strain-induced transformation (TRIP effect). The project proposed for this research internship at the Colorado School of Mines-USA aims to understand more deeply how the SFE and the TRIP effect are impacted by C- and N-doping in the Cr40Co40Ni20 MPEA.