The platinum group metals (PGM, Pd, Pt, Ir, etc.) possess unique chemical and physical properties, the properties often vary dramatically with their size, morphology, crystal structure, phase and composition. However,...
The development of high-performance rechargeable batteries highly depends on the rational structure/phase design of advanced electrode materials. A unique 2D lamellar stacked nanosheet VS2/MoS2 heterostructure is synthesized using a simple...
The established regularities of the formation of powders based on iron and nickel, obtained by the method of mechanical alloying and intended for the deposition of thermal spraying coatings, as well as the manufacture of products by layer‑by‑layer synthesis. The structure, phase composition and properties of materials are investigated. Powders consist of particles with a size of 20–70 microns, differ in the submicrocrystalline type structures, and nonequilibrium phase composition. Thermal spray coatings made of them have a set of properties that significantly exceed the properties of coatings made of commercially available materials. The diameter of the grains of the material obtained by the SLМ method from the synthesized powder is 1.5–2.0 times smaller than that produced from the powder of 316L steel, and the heat resistance is higher.
Abstract
Crystalline phase and microstructure control are critical for obtaining desired properties of Ta films deposited by magnetron sputtering. Structure, phase evolution, and properties of Ta films deposited by using hybrid high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS) under different fractions of DCMS power where Ta ion to Ta neutral ratios of the deposition flux were changed are investigated. The results revealed that the number of Ta ions arriving on the substrate/growing film play an important role in structure and phase evolution of Ta films. It can effectively avoid the unstable arc discharge under low pressure and show a higher deposition rate by hybrid high power impulse magnetron sputtering (HiPIMS) and direct current magnetron sputtering (DCMS) compared with only high power impulse magnetron sputtering (HiPIMS). Meanwhile, the high hardness α-Ta films can be directly deposited by hybrid co-sputtering compared to those prepared by direct current magnetron sputtering (DCMS). In the co-sputtering technology, pure α-Ta phase film with extremely fine, dense and uniform crystal grains were obtained, which shows smooth surface roughness (3.22 nm), low resistivity (38.98 μΩ·cm) and abnormal high hardness (17.64 GPa).
Compact ceramic materials based on the Ti‒B system modified with 5 wt. % of nanosized Si3N4 particles. The results of studies of the structure, phase composition, and physical and mechanical characteristics of the materials obtained are presented. It is shown that the addition of Si3N4 promotes the formation of new phases, in particular, titanium diboride and nitride in the final product. It was found that the introduction of modifying nanosized Si3N4 particles into the initial charge leads to an increase in hardness and microhardness by 15‒20 %, as well as to an increase in crack resistance by 1,5 times in comparison with unmodified samples.
Spatial structure, phase, and the contrast of natural images