Calculation of lattice parameters and elastic constants of Cr3Ti and Cr3Al phases with L12 structure via density functional theory

• Grant number: 20/13225-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2021
• End date: June 30, 2022
• Field of knowledge: Engineering - Materials and Metallurgical Engineering
• Principal Investigator: Francisco Gil Coury
• Grantee: Gabriella Barcellos Carneiro
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Multicomponent alloys are a new class of materials composed of concentrated solid solutions. Currently, focus has been given to the so-called second generation alloys, which are alloys that contain two or more phases and the main research focus is on (1) increasing toughness via TWIP / TRIP effects or (2) increasing high and room temperature mechanical strength through the formation of coherent nanometric precipitates that increase strength with minimal ductility losses. The mechanical resistance of these precipitation hardened materials is influenced by several factors, including the lattice parameter and elastic moduli of the precipitate phase. In the present work the elastic properties and lattice parameters of L12 Cr3Al and Cr3Ti phases will be calculated using the Density Functional Theory. The lattice parameter will be calculated via the relaxation of the unit cell of these phases and the elastic constants will be calculated using the total energy method. Although these phases are thermodynamically metastable, their properties matter to understand the effect of Cr in this type of precipitate. The results will be compared with the parameters of the phases without Cr to understand the effect of Cr on them. The results will be important to better understand the mechanisms of resistance to cutting of precipitates rich in Cr by dislocations in High Entropy Alloys. (AU)