Coatings, with a thickness of up to 75 µm, were formed by plasma electrolytic oxidation (PEO) under the alternating current electrical mode in a silicate-alkaline electrolyte on aluminum composites without additives and alloyed with copper (1–4.5%). The coatings’ structure was analyzed by scanning electron microscopy, X-ray microanalysis, X-ray photoelectron spectroscopy, nuclear backscattering spectrometry, and XRD analysis. The coatings formed for 60 min were characterized by excessive aluminum content and the presence of low-temperature modifications of alumina γ-Al₂O₃ and η-Al₂O₃. The coatings formed for 180 min additionally contained high-temperature corundum α-Al₂O₃, and aluminum inclusions were absent. The electrochemical behavior of coated composites and uncoated ones in 3% NaCl was studied. Alloyage of aluminum composites with copper increased the corrosion current density. Plasma electrolytic oxidation reduced it several times.

The article discusses the influence of the thickness of the wear-resistant layer of the Zr-ZrN-(Zr,Al,Si)N nanolayer composite coating on the values of residual stress and the nature of coating wear. The study focused on coatings with wear-resistant layer thicknesses of 2.0, 4.3, 5.9, and 8.5 µm, deposited using filtered cathodic vacuum arc deposition (FCVAD) technology. The X-ray diffraction (XRD) method based on the anisotropy of the elasticity modulus was used to find the values of the residual stress. The nature of the formation of interlayer delamination under the influence of residual compressive stress was studied using a scanning electron microscope (SEM). When the wear-resistant layers had a thickness of 2.0–5.9 μm, tensile stress formed, which decreased with an increase in the thickness of the coating. When the thickness of a wear-resistant layer was 8.5 μm, compressive stress formed. Under the action of compressive stress, periodic interlayer delamination formed, with a pitch of about 10 binary nanolayers. A mathematical model is proposed to describe the nature of the formation of interlayer delamination under the influence of compressive residual stress, including in the presence of a microdroplet embedded in the coating structure.

Using high-temperature X-ray diffraction, differential scanning calorimetry, and electron microscopy, we have studied the formation of yttrium aluminates and Nd:YAG (YAG) activated garnet nanoparticles during the thermal decomposition of a poorly crystallized carbonate precursor prepared in the NH₄Al(OH)₂CO₃–(Y,Nd)(ОН)CO₃ nanosystem and the development of the morphological structure of powders during heating to a temperature of 1350°C. The results demonstrate that heat treatment in the temperature range 850–950°C leads to the formation of metastable nonstoichiometric YAlO₃ with a garnet-like structure, which reacts with Al₂O₃ at a temperature of 1000°C to form YAG. The cubic cell parameter a and X-ray density of YAG crystals with the composition Y_2.97Nd_0.03Al₅O₁₂ synthesized at 1200°C are 1.2009 nm and 4.565 g/cm³, respectively, and the average particle size is 108 nm. Using carbonate route, we prepared transparent Nd:YAG ceramics with a relative density of 99.7%, X-ray density of 4.562 g/cm³, and crystallite size in the range 1–7 μm.

Methods of X-ray diffraction and thermal analysis have been used to study the processes of the formation of activated yttrium aluminum garnet Y₃Al₅O₁₂:Nd (YAG:Nd) upon the thermal decomposition of carbonate precursors (two-phase nanocrystalline (Y,Nd)(OH)CO₃ · nH₂O-NH₄Al(OH)₂CO₃ and an amorphous material) obtained by the coprecipitation from a solution of inorganic salts. It has been shown that the cubic structure of the garnet begins forming at a temperature of 900°C and is developed from the hexagonal metastable yttrium aluminate YAlO₃, which starts forming (as an intermediate phase) at 800°C. The values of the lattice parameter a of the cubic structure and the X-ray density of the synthesized garnet Y_2.97Nd_0.03Al₅O₁₂ for the sample of the transparent phase-pure ceramics obtained are 1.2011 nm and 4.562 g/cm³, respectively.

The injectable hydrated calcium phosphate bone-like paste (hCPP) was developed with suitable rheological characteristics, enabling unhindered injection through standard 23G needles. In vitro assays showed the cytocompatibility of hCPP with mesenchymal embryonic C3H10T1/2 cell cultures. The hCPP was composed of aggregated micro-sized particles with sphere-like shapes and low crystallinity. The ability of hCPP particles to adsorb serum proteins (FBS) was investigated. The hCPP demonstrated high protein adsorption capacity, indicating its potential in various biomedical applications. The results of the in vivo assay upon subcutaneous injection in Wistar rats indicated nontoxicity and biocompatibility of experimental hCPP, as well as gradual resorption of hCPP, comparable to the period of bone regeneration. The data obtained are of great interest for the development of commercial highly effective osteoplastic materials for bone tissue regeneration and augmentation.

—This paper presents a study of organomagnesiumoxaneyttroxanealumoxane oligomers soluble in organic solvents and exhibiting fiber-forming properties. We describe processes underlying the...