Evaluation of ordering effect on the properties of Multicomponent CrCoNi Alloys

• Grant number: 22/12641-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2023
• End date: February 29, 2024
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Francisco Gil Coury
• Grantee: Vinícius Pereira Bacurau
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Medium (MEA) and/or high entropy (HEA), complex and concentrated (CCA) alloys and multi-principal element alloys (MPEA) are different nomenclatures used for a new class of materials, whose main features is the absence of a main element in its composition. Recent works expose the need to understand, develop and improve this new class of alloys, because some compositions have shown to be promising with properties comparable or even superior to conventional engineering alloys. The equiatomic CrCoNi alloy, one of the derivatives of the Cantor alloy, stands out in the literature due to its excellent mechanical properties at room and cryogenic temperatures, being this alloy is considered one of the toughest ever reported in the literature under cryogenic conditions. However, there are contributions to the mechanical properties of the equiatomic CrCoNi alloy, which have not been fully elucidated. One of the possible contributions, which is under great debate in the literature, is the short-range ordering (SRO), which can be defined as a preference/avoid of coordination of a certain constituent element in the league by another. Due to the complexity of this phenomenon, it is necessary to use advanced characterization techniques to understand its mechanisms. The present work seeks to evaluate 3 compositions that will be produced, Co33Cr33Ni33, Co15.5Cr33Ni50.5 e Cr33Ni66, based on the binary alloy Cr33Ni66 which demonstrably exhibits ordering, allowing to measure the behavior of the ternary alloy, which presents various ambiguities reported in the literature. Through heat treatments under conditions in which SRO will be extremely favored, the microstructural and mechanical properties changes will be investigated. Therefore, the objective of the research is to complement the literature with more information on SRO, for the multicomponent alloys in the CrCoNi system, through indirect evaluations as measures of mechanical properties and direct microstructural characterization.