Influence of Nanoparticles Deposition Conditions on the Microarc Coatings Properties

The surface charge of biomaterials significantly contributes to such processes as protein adsorption or biofilm formation and consequently osseointegration bone tissue and implant. There are a set of methods to create a charge on dielectric biomaterials surface. One of the perspective methods of materials electrization is an introduction of the nanoparticles with appropriate biomedical properties into biomaterial. Boehmite AlO(OH) nanoparticles is perspective for the biomaterials surface modification due to its high surface area and positive charge. In this work, the investigations of microarc calcium phosphate biocoatings modified by boehmite nanoparticles on the Ti substrate were presented. A variation of the nanoparticles deposition parameters allowed producing calcium phosphate coatings with different morphology and boehmite nanoparticles size distribution. The investigations of the modified coatings by the transmission and scanning electron microscopy methods are presented in the work

On a joint quantized and mechanical description for the Chernov-L\"uders macroband of localized deformation

We suggest a quantum procedure, based on our recent statistical theory of flow stress in polycrystalline materials under quasi-static plastic deformations, with the intention to approach a theoretical description of the Chernov-L\"uders shear macroband of localized deformation, exhibited by some Fe-containing materials with a second phase beyond the yield-strength point on the stress-strain curve {\sigma}={\sigma}({\epsilon}). The procedure makes substantial use of a quasi-particle interpretation for the minimal portion of mechanical energy in a given single-mode polycrystalline aggregate that is necessary for the thermal-fluctuation mechanism to create a 0D-defect nanopore as the initial zone of a localized deformation under external loading. Using a quasi-particle description, we obtain analytic expressions both for the scalar density of dislocations, given the size of grains, the temperature, the most probable sliding system, and for the dependence {\sigma} ={\sigma}({\epsilon}) itself. A two-level system, which characterizes the mechanism of absorption and emission of such quasi-particles (dislocons) by the crystal lattice of any grain under quasi-static loading provides an effective physical description for the emergence and propagation of the Chernov-L\"uders shear macroband. An enhancement of acoustic emission observed in experiments and accompanied by the macroband phenomenon justifies the interpretation of a dislocon as a composite short-lived particle consisting of acoustic phonons. A more realistic three-level system within a two-phase model with third (with dispersion particles) phase presence for actual polycrystalline samples is also produced.Comment: 5 pages, 2 figures, 1 table, contribution to the Proceedings of the International Conference Advanced Materials with Hierarchical Structure for New Technologies and Reliable Structures 1-5, October, 2019, Tomsk, Russi

Microstructure and mechanical properties of Ti40Nb alloy after severe plastic deformation

The study presents the analysis of microstructure, phase composition and mechanical properties of Ti40Nb alloy exposed to severe plastic deformation. It was shown that isothermal multi-axial forging and further multi-pass rolling intensify the formation of ultra-fine grained structure in the bulk of a billet with the average element size of 0.3 ?m. Such ultra-fine grained structure considerably improves the alloy mechanical properties

Investigation of high-energy external influences on structural heredity of the Ti-Nb alloy

The effects of high-energy external influences on structural heredity of Ti-Nb alloy is investigated in this paper. By the methods of XRD, SEM, EDX and optical microscopy it was founded that thermal treatment and severe plastic deformation lead to the phase transformations in the alloy, the dendritic segregation occurs and retains in the alloy under external influences

Fracture characteristics of titanium VT1-0 and Zr–1 wt. % Nb alloy in different structures under gigacycle fatigue loading regime

Fatigue testing of ultrafine-grained, fine-grained and coarse-grained VT1-0 and Zr–1 wt. % Nb samples was performed under conditions of gigacycle fatigue regime. It was established that ultrafine-grained titanium and zirconium alloy samples initiate increasing fatigue strength of up to 1.3 times for titanium and 1.7 times for zirconium alloy within gigacycle region (109 cycles) comparable to fine-grained and coarse-grained samples. Analysis of fracture surface morphology has revealed the similar fractured structure in coarse-grained and ultrafine-grained titanium and zirconium alloy samples. Fractures in ultrafine-grained titanium and zirconium alloy samples exhibit quasi-brittle pattern

Influence of layer-by-layer laser sintering conditions on the quality of sintered surface layer of products

The influence of technological modes of sintering: the displacement velocity of laser beam V, laser power P, scanning step S and preheating temperature of powder material t on the quality of sintered surface layer of aluminum powder PA-4, copper powder PMS-1 and cobaltchromium- molybdenum powder DSK-F75 were studied