Development of Refractory Multicomponent Alloys with Enhanced Resistance to High-Temperature Oxidation

• Grant number: 24/15724-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2024
• End date: October 31, 2025
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Carlos Alberto Della Rovere
• Grantee: Guilherme Sabio Antonio
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 22/03139-9 - Design and production of multicomponent refractory alloys with optimized high-temperature oxidation properties, AP.PNGP.PI

Abstract

Refractory multicomponent alloys have emerged as a new class of materials characterized by their unique combination of primary refractory elements, gaining significant attention from both the scientific community and industry due to their potential performance in extreme environments. This study focuses on refractory multicomponent alloys of the NbMoTaW and VNbMoTaW systems, selected based on their high yield strength at ultra-high temperatures (1,200 to 1,600 °C), but which exhibit low oxidation resistance due to "pesting" and the formation of non-protective and volatile oxides. Therefore, this study aims to select, produce, and characterize the high-temperature oxidation behavior of refractory multicomponent alloys of the NbMoTaW (Al, Cr, Si) and VNbMoTaW (Al, Cr, Si) systems. The addition of Al, Cr, and Si has shown promising results in other refractory multicomponent alloys systems but has not yet been applied to these specific alloys. The selection of alloy compositions will be conducted after intensive and systematic research (i.e., computational thermodynamic simulation) using the Thermo-Calc software. The objective is to develop novel compositions that present promising microstructures for thermal stability at high temperatures (¿ 1000 °C) and optimized oxidation resistance. The microstructure of the alloys and their oxidation behavior in air will be investigated through isothermal oxidation tests at 1000 - 1200 °C for extended periods (up to 100 h), optical microscopy (OM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), and X-ray diffraction (XRD).