The processes of superstructure formation were investigated using nanocomposites composed of inorganic scintillators based on lanthanum bromide and cesium iodide and an organic luminophore based on polystyrene, under deformation, electrical, ultrasonic and laser exposures. It was shown that for certain combinations of nanocomposite compositions and exposure parameters, structuring develops at molecular‑cluster and optical scales, which is of interest for the development of improved radiation detectors.
This study examines the flow patterns of viscoelastic-plastic filler in a molded volume during the manufacturing of repair parts for mining machinery and equipment. Promising technologies for the rapid manufacturing of metal-composite mining machine parts, such as metal-composite technology, require a mathematical description and functional dependencies describing the flow of metal-polymer composite materials (MPCMs) in complex channels formed by mold voids. The objectives of this study are to mathematically describe the MPCM flow process in mold channels and to derive mathematical dependencies describing the optimal channel shape. The paper analyzes a number of studies related to the search for the optimal surface shape ensuring minimal descent time when solving various engineering problems. It is revealed that all solutions are based on the properties of brachistochrone. However, in the process under consideration, additional conditions are imposed when formulating the problem, such as resistance, viscous or dry friction, the movement of solid or viscoelastic-plastic bodies, and others, resulting in a brachistochrone shape other than a cycloid. An equation was obtained for the generatrix that ensures the least work done by the friction forces of the wall-adjacent layers of the MPCM on the mold walls. The resulting mathematical relationship can be applied to the design of internal mold channels using specialized computer programs.
Steady‑state and pulsed X‑ray luminescence of nanocomposites based on polystyrene and inorganic scintillators (cerium‑doped lanthanum bromide LaBr3(Ce) and thallium‑doped cesium iodide CsI(Tl)) were investigated. The formation of high‑speed emission pulses of nanosecond duration with substantially enhanced intensity was observed. For certain combinations of composition and preparation conditions, the primary emission is concentrated in a fast nanosecond component with high light output. This is explained by the formation of molecular‑cluster assemblies in which interaction between the electronic and vibrational states of the organic and inorganic components initiates a new shock‑vibronic (impact‑vibronic) excitation mechanism.
The effect of selective laser melting (SLM) modes on melt bath geometry and defect porosity of solid materials and lattice structures made of medical-grade Ti–Zr–Nb alloys was studied. Based on the analysis of melt bath geometry formed by single and multiple laser passes, an approach was developed to optimize SLM modes for producing porous materials based on lattice structures made of Ti–Zr–Nb alloys with thin (250–340 μm) structural elements and a low defect count. It was found that modes with reduced scanning speed (700–1000 mm/s) and laser power (45–60 W) ensure high geometric accuracy due to reduced melt bath size and low defect porosity (<0.75
For the first time, the relationship between the firing time of ceramics based on the solid solution (Ba,Ca)(Ti,Sn)O3 containing 12 wt
