A critical evaluation and optimization of all reliable experimental thermodynamic properties and phase diagram data of the Dy–Nd–Fe–B system has been performed to obtain the best set of model parameters to describe the Gibbs energy of all phases in the system. Thermodynamic models with optimized model parameters can be used to predict unexplored phase diagrams and complex thermodynamic equilibria. The thermodynamic database of the Mg–Dy–Nd–Fe–B system was prepared by integrating the present model parameters to the FactSage light alloy database (FTlite) and was applied to perform comprehensive thermodynamic analyses of the selective extraction and purification process of Nd and Dy from the NdFeB permanent magnet scrap using molten Mg. Essential process parameters such as temperature, magnet to solvent ratio, vacuum pressure, heat requirement, etc. are determined in order to maximize the selective extraction of the RE metal from the magnet scrap and produce an RE alloy with low impurity content.

Proton exchange membrane fuel cell (PEMFC) is a renewable energy source rapidly approaching commercial viability. The performance is significantly affected by the transfer of fluid, charges, and heat; gas diffusion layer (GDL) is primarily concerned with the consistent transfer of these components, which are heavily influenced by the material and design. High-efficiency GDL must have excellent thermal conductivity, electrical conductivity, permeability, corrosion resistance, and high mechanical characteristics. The first step in creating a high-performance GDL is selecting the appropriate material. Therefore, titanium is a suitable substitute for steel or carbon due to its high strength-to-weight and superior corrosion resistance. The second crucial parameter is the fabrication method that governs all the properties. This review seeks to comprehend numerous fabrication methods such as tape casting, 3D printing, freeze casting, phase separation technique, and lithography, along with the porosity controller in each process such as partial sintering, input design, ice structure, pore agent, etching time, and mask width. Moreover, other GDL properties are being studied, including microstructure and morphology. In the future, GeoDict simulation is highly recommended for optimizing various GDL properties, as it is frequently used for other porous materials. The approach can save time and energy compared to intensive experimental work.

Although TiNb₂O₇is regarded as a material with high application potential in lithium-ion batteries (LIBs) and solid-oxide fuel cells (SOFCs), it has been difficult to find suitable cost-effective conditions for synthesizing it on a commercial scale. In this study, TiNb₂O₇compounds were synthesized by a solid state synthesis process. For stoichiometrically precise synthesis of the TiNb₂O₇phase, the starting materials, TiO₂and Nb₂O₅were taken in a 1:1 molar ratio. Activation energy and reaction kinetics of the system were investigated at various synthesis temperatures (800,1000,1200, and 1400°C) and for various holding durations (1,5,10, and 20 h). Furthermore, change in the product morphology and particle size distribution were also evaluated as a function of synthesis temperature and duration. Additionally, quantitative phase analysis was conducted using the Rietveld refinement method. It was found that increases in the synthesis temperature and holding time lead to increase in the mean particle size from 1 to 4.5 μm. The reaction rate constant for the synthesis reaction was also calculated.