High entropy alloys of Ti-V-Cr-Nb-M systems (M= Mn, Fe, Ni): milling and consolidation by severe plastic deformation, characterization, and hydrogen storage properties

• Grant number: 24/17259-1
• Support Opportunities: Regular Research Grants
• Start date: March 01, 2025
• End date: February 28, 2027
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Physical Metallurgy
• Principal Investigator: Gisele Ferreira de Lima Andreani
• Grantee: Gisele Ferreira de Lima Andreani
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Federal de São Paulo (UNIFESP). Campus São José dos Campos. São José dos Campos , SP, Brazil

Abstract

Fossil fuels are limited energy sources associated with greenhouse gas emissions, global warming, and climate change. An economy based on green hydrogen (obtained from renewable sources) is an exciting alternative, as this energy vector only releases water as a by-product and has high-energy power. Among the various possibilities, storing hydrogen in the solid state, in the form of metal hydride, is more efficient and safe. Mg-based hydrides have high capacities but are unfeasible in operating conditions (temperature and pressure). High entropy alloys (HEAs) are a new class of unconventional multicomponent metallic materials. HEAs are promising for hydrogen storage, as most are reversible and may reach high storage capacity (H/M = 2.5) because of lattice distortion factors due to the constituent elements' different atomic radii and a more significant number of interstitial positions. HEAs with CCC structures are better for hydrogen storage than conventional CCC alloys of the Ti-V-Cr system. In this project, we want to study the HEAs of the Ti-V-Cr-Nb-M (M= Mn, Fe, Ni) systems. Elements V and Nb have a high affinity for hydrogen, and their hydrides have more viable operating conditions (ambient). The HEAs will be produced from pure elements by high-energy ball milling (HEBM) and reactive milling (RM) under hydrogen. The microstructural characterization will use XRD, SEM, and TEM techniques. Hydrogen desorption properties will be measured by DSC/TG. The samples will also be consolidated/processed by accumulative roll bonding (ARB) to evaluate the effect of severe plastic deformation (SPD) on the properties of the samples. (AU)