Design, Synthesis and Characterization of Hydrogen Storage Properties in Multicomponent Alloys of the TiZrNbCrNiCo and TiZrVFeNi System

Abstract

The present master's project involves the design, selection, processing and characterization of multicomponent alloys from the systems: TiZrNbCrNiCo and TiZrVFeNi, which can demonstrate good properties for hydrogen storage in the solid state. From the combination between elements with high affinity for hydrogen and hydride formers (such as Ti, Zr, Nb and V) and elements with low affinity for hydrogen (such as Cr, Ni, Fe, Co), within the compositional space existing in the systems: TiZrNbCrNiCo and TiZrVFeNi, it is intended to use the potential of thermodynamic simulation (CALPHAD method with the aid of Thermocalc software) to study the variation of phases resulting from the composition change of each element in the alloy, selecting single-phase C14-type compositions of interest, which can exhibit the hydrogen storage properties of a high reversible metal hydride. After the selection of the alloys, they will be produced in an arc furnace in a controlled atmosphere and have their hydrogen storage properties characterized in details. For this, the following specific objectives should be carried out:- Design of new alloys, within the TiZrNbCrNiCo and TiZrVFeNi systems, with single phase configurations that result in the presence of the C14 phase in a majority form in its phase equilibrium state, by means of thermodynamic calculations using the CALPHAD method.-The production of the selected alloys in thermodynamic simulation and the consequent characterization of the materials, in order to validate the phase equilibrium predictions and, thus, ensure that the alloys obtained have the potential to store hydrogen, so that they can exhibit full reversibility at room temperature, with low equilibrium pressures and fast kinetics.- The creation of pressure x composition x temperature (PCT) isotherm curves and the kinetics of absorption and desorption, and the consequent evaluation of the hydrogen storage performance of the selected alloys;- Investigate the storage capacity of selected multicomponent alloys and contribute to a better understanding of the main microstructural, thermodynamic, compositional and kinetic factors that influence hydrogen storage in multicomponent alloys with the presence of C14-type laves phase;