The on-site hydrogen supply is a key issue for the commercialization of the fuel cells, which is one of the important ways for realizing a hydrogen-economy society. Composite NaNH2–NaBH4 is regarded as a promising high-capacity hydrogen storage material. In this paper, the composite NaNH2–NaBH4 (2/1) was synthesized via a solid-state ball milling method. To improve the hydrogen generation kinetics, a multiplex metal boride Mg–Co–B was selected as the catalyst. It was found that Na3BN2 and metal Na were byproducts in the thermal decomposed sample by X-ray diffraction analysis. Thermogravimetry and differential thermal analysis indicated that the main decomposition stages of the catalyst promoted NaNH2–NaBH4 material were split into three stages. The activation energy of the Mg–Co–B promoted NaNH2–NaBH4 (2/1) material below 300 °C was 76.4 KJ/mol, which is only 47.9% of that of the pristine NaNH2–NaBH4 (2/1), and implying much better hydrogen generation kinetics.

The strain-rate sensitivity of the flow stress represents a crucial parameter for characterizing the deformation kinetics of a material. In this work a new method was developed and validated for determining the local strain-rate sensitivity of the flow stress at different plastic strains. The approach is based on spherical nanoindentation strain-rate jump tests during one deformation experiment. In the case of ultrafine-grained Al and ultrafine-grained Cu good agreement between this technique and macroscopic compression tests has been achieved. In contrast to this, individual spherical nanoindentation experiments at constant strain-rates resulted in unrealistically high strain-rate sensitivities for both materials because of drift influences. Microstructural investigations of the residual spherical imprints on ultrafine-grained Al and ultrafine-grained Cu revealed significant differences regarding the deformation structure. For ultrafine-grained Cu considerably less activity of grain boundary sliding has been observed compared to ultrafine-grained Al.

Bioactive glasses and related bioactive glass-ceramics have been used for over three decades in biomedical applications such as bulk, particulate, or coatings materials. More recently, highly porous bioactive glass-ceramic scaffolds for bone-tissue engineering have also been developed from selected compositions of bioactive glasses. Current bioactive glass-ceramic scaffolds are characterized by an open porous network, high bioactivity, and mechanical properties similar to those of trabecular bone. This article reviews the latest achievements in the development of porous bioactive glass-ceramics intended for bone-tissue engineering applications, highlighting the fabrication technologies and scaffold properties. Improvements in the mechanical properties of bioactive glass-ceramic scaffolds exhibiting high bioactivity have been achieved by different approaches in the last 10 years. Relevant long-term in vivo studies are required to confirm the suitability of such bioactive glass-ceramic scaffolds in clinical applications.

Materials designed and engineered for technical applications must invariably meet or exceed multiple key specifications. Even if commercial realization is not intended, scientific interest is piqued if a challenging combination of properties is achieved, particularly if they are mutually exclusive for certain classes of materials. For example, the combination of mechanical toughness, chemical durability, and high thermal-shock resistance, with pore-free, smooth, aesthetically beautiful surfaces simultaneously realized in certain glasses that are crystallized in a controlled manner—glass-ceramics—have enabled two distinct, decades-long applications, cookware and flat cooktop panels. Other special glass-ceramic materials have been developed for electronic, photonic, dental, and biomedical applications. No other class of material could combine these properties in such an advantageous and economically feasible manner. This issue highlights six very different innovative applications of glass-ceramics, all of which owe their importance and continuing interest to “hard-to-combine” properties.

Many current technological applications are based on the electrical properties of materials. Among these, ferroelectricity, antiferroelectricity, paraelectricity, and resistivity are the most important to be studied and controlled. To overcome important drawbacks of sintered ceramics or single crystals with these characteristics, the preparation of glass-ceramics with these phases dispersed in a glass matrix is a possible solution. The formation of glass-ceramics shows great advantages—their properties (optical, electrical, mechanical, and chemical) can be controlled via the volume fraction of the dispersed active phase. Thus, the preparation and properties of glass-ceramics containing ferroelectric crystallites embedded in the glass matrix have received considerable interest. This article discusses state-of-the-art preparation of glass-ceramics with one important technological ferroelectric crystal, lithium niobate (LiNbO3). Since the preparation of LiNbO3 single crystals by traditional growth techniques is technically difficult and economically costly—and with dense ceramics, it is difficult to achieve a congruent composition—scientific research on the fabrication methods of inorganic glasses containing LiNbO3 crystallites is an important current topic.