Design and production of multicomponent refractory alloys with optimized high-temperature oxidation properties

• Grant number: 22/03139-9
• Support Opportunities: Research Grants - Initial Project
• Start date: February 01, 2023
• End date: January 31, 2028
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Carlos Alberto Della Rovere
• Grantee: Carlos Alberto Della Rovere
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated researchers: Frederico Augusto Pires Fernandes ; Jorge Otubo
• Associated scholarship(s): 24/15724-9 - Development of Refractory Multicomponent Alloys with Enhanced Resistance to High-Temperature Oxidation, BP.IC

Abstract

Over the last two decades, the concept of multi-component alloys has been explored with increasing intensity by researchers around the globe. This new concept of designing metallic alloys, which involves the use of several main elements instead of just one, has made it possible to achieve amazing sets of properties, previously unseen in conventional alloys. A specific class that shows great potential for applications as high-temperature structural materials are the refractory multi-component alloys. These alloys follow the same concept of having several main elements, but with the largest atomic fraction being occupied by the so-called refractory metals. Due to their very high melting temperatures, these materials are also able to retain excellent mechanical strength as the temperature is increased. A multicomponent refractory alloy system that stands out in this aspect is composed of NbMoTaW and VNbMoTaW alloys. Such alloys have unmatched yield strength values at ultra-high temperatures of application (between 1,200 and 1,600°C). However, a factor that limits their application is their low resistance to oxidation, and improving this resistance is a great challenge because they suffer from the pesting phenomenon and also from the formation of non-protective and/or volatile oxides. Therefore, the purpose of this research is design and produce NbMoTaW and VNbMoTaW alloys with optimized high-temperature oxidation properties, through 2 different ways: (1) controlled addition of alloying elements able to afford the formation of stable and protective oxide layers at high temperature (i.e., Al, Cr, and Si) and (2) surface treatments. It is noteworthy that these procedures have already shown promising results when applied to other refractory multicomponent alloy systems, but they have never been tested on the NbMoTaW and VNbMoTaW systems. After applying these procedures and techniques, the high-temperature oxidation behavior of the elaborated alloys will be studied: (i) in a thermogravimetric analyzer (TGA) at temperatures ranging from 1,000 to 1,300°C, in controlled atmospheres (i.e., synthetic air and pure O2) for up to 100 h; and (ii) by means of cyclic oxidation tests in air (i.e., uncontrolled atmosphere) at the same temperatures and times mentioned in item (i). In the sequence, both the microstructure of the produced alloys and the oxide layers formed will be characterized mainly through scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD). With this, it is expected to optimize the oxidation resistance of NbMoTaW and VNbMoTaW alloys and to characterize in-depth their high-temperature oxidation behavior, as well as to infer about the oxidation mechanisms acting on each alloy under different treatment conditions. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DAINEZI, ISABELA; GLEESON, BRIAN; BUZATTI, BRUNO RESENDE; MALAFAIA, ARTUR MARIANO DE SOUSA; DELLA ROVERE, CARLOS ALBERTO. TiNbCr Multi-Principal Element Alloy Oxidation Behavior in Air at 800-1000 °C. HIGH TEMPERATURE CORROSION OF MATERIALS, v. 101, n. 4, p. 22-pg., 2024-04-29. (22/03139-9)

DAINEZI, ISABELA; GLEESON, BRIAN; DELLA ROVERE, CARLOS ALBERTO. Failure analysis of TiNbCr Multi-Principal element Alloy: Temperature-Dependent oxidation and internal degradation in oxygen atmospheres. ENGINEERING FAILURE ANALYSIS, v. 175, p. 10-pg., 2025-06-15. (22/03139-9)

MARTINS JUNIOR, C. B.; SILVA, R.; GARGARELLA, P.; GLEESON, B.; ROVERE, C. A. D.. Characterization of NiTiNb10.5 shape memory alloy: microstructural aspects and high-temperature oxidation behavior. Corrosion Science, v. 225, p. 12-pg., 2023-10-31. (17/27031-4, 22/03139-9, 19/23610-5)