Decomposition Staging of

The decomposition of β-metastable phase in (α+β)-titanium alloys during continuous heating needs a detailed investigation in the range of relatively small temperatures. The staging of β-solid solution decay was studied on the solution treated and water quenched VT16 (Ti-3Al-5Mo-5V) used for fasteners production. The thermal exo-effects of β-phase decomposition were examined using DSK. Corresponding effects in the in situ X-Ray diffraction patterns and storage modulus temperature dependence in the DMA curves are discussed. A three stage layout of β-decay is reported during continuous heating of VT16 with (α+β)-structure after quenching.     Keywords: metastable phase, phase transformation, in situ XRD, storage modulus, decay, quenching, continuous heating, dynamic mechanical analysi

Influence of Cold Rolling Temperature Rise on the Young‘s Modulus of Commercial Fe-3%Si Steel

Dynamic mechanical analysis was performed on the sheets of commercial grainoriented steel Fe-3%Si in annealed and cold-rolled conditions. The Young‘s modulus was measured according to the 3-point bending scheme in the temperature range of 20…550 ∘C. The difference between the values of the elastic properties in the rolling direction and transverse directions were explained with the peculiarities of the structural and textural states. Two extreme points in the Young‘s modulus temperature dependence are explained with the oxidation process, which occurs during heating of the samples. The obtained data can be employed to refine the simulation of the stress-strain state in cold rolling of commercial Fe-3%Si by the finite element method.     Keywords: Grain-oriented steel, cold rolling, storage modulus, dynamic mechanical analysis, anisotropy, crystallographic textur

Analysis of Bending Test Technique for Osteosynthesis Titanium Plate

Abstract Titanium and its alloys often take the role of material for manufacturing the implants for orthopedic use. The purpose of the study is to determine the parameters of bending test of an implantable titanium plate used for osteosynthesis. The method described in the ISO 9585-2011 was analyzed for testing metal plates for fixation of fractured bone fragments. A comparison of the test results for plates on a 4-point bending for two different standards and the results of experiments are reported. The attention is drawn to the possibility of weakening of titanium plates with fixation holes.     Keywords: 4-point bending test, plate for osteosynthesis, titanium implant, mechanical propertie

Osteointegration Characterization of Additive Manufactured Porous Titanium Scaffold Based on Microhardness and Ca/P Ratio

Additive technologies are getting widely used in orthopedics due to the opportunity of full modelling of complex cellular structures and producing personalized implants. Titanium and its alloys are still the main material used for metallic implants manufacturing. In this study microhardness and Ca/P ratio of bone tissue surrounding the implant were investigated. By means of ABAQUS software titanium porous structure implants were designed. Their biomechanical properties were close to biomechanical properties of trabecular bone tissue. Direct metal laser sintering (DMLS) was used to manufacture implants from Ti-6Al-4V titanium alloy. They were augmented in trabecular bone defects of Chinchilla rabbits for 6, 12 and 25 weeks. The samples were examined by scanning electron microscopy (SEM) in a FEG SEM ZEISS CrossBeam AURIGA and the Ca/P ratio was calculated using the accompanying Oxford Inca software. Vickers hardness test method was performed for microhardness. It was shown that there was a significant increase in both mineral and mechanical properties of bone samples with an increase of observation period. The results found in this study illustrate a distinct relationship between the mineralization parameter of bone tissue and its microhardness (r = 0.808, r2 = 0.65).     Keywords: Scaffold, Microhardness, Titanium, Ca/P ratio, Bone defect, Osteointegration, Additive manufacturin

Estimation and minimization of the influence of various supporting devices on the integral aerodynamic characteristics of the models of axisymmetric bodies and isolated helicopter fuselages in a low-speed wind tunnel

Estimation and minimization of influence of supporting devices on the aerodynamic characteristics of various bodies during the wind tunnel tests has always attracted considerable attention. The three-dimensional interference of a model and supports is quite complex. It depends on the type of the supporting devices, the character of the flow around the bodies, the angle of attack and the yaw angle. The influence of the suspension system causes the emergence of the systematic measurement errors. Corrections for this influence are especially important for well-streamlined wind-tunnel models (axisymmetric bodies, isolated fuselages of airplanes and modern helicopters.) Systematic experimental investigations were carried out in the wind tunnel of KNRTU-KAI in order to determine the influence of various supporting devices on the aerodynamic characteristics of axisymmetric bodies with different aspect ratios and helicopter fuselage models. The supports drag was minimized with the help of a single-panel suspension system, which was designed at the Aerodynamics department of MAI. This approach allowed to identify the influence of various suspension devices (bottom struts and side support stings) on the integral aerodynamic characteristics of various models. It also helped to estimate the nature (cause) and magnitude of the required corrections

Poloidal inhomogeneity of the particle fluctuation induced fluxes near of the LCFS at lower hybrid heating and improved confinement transition at the FT-2 tokamak

This paper deals with the new spectral and microturbulence experimental data and their analysis, which show, that the radial electric field Er generated at the LH heating (LHH) in the FT-2 is high enough to form the transport barriers. The ETB is formed when LHH is switched off. The radial fluctuation-induced EB drift flux densities near LCFS in SOL are measured at two different poloidal angles. For this purpose two Langmuir probes located at low and high field sides of the torus are used. Registration of the poloidal and radial components of the electric field and density fluctuations at the same time during one discharge permits to measure the poloidal asymmetry of the transport reduction mechanism of the radial and poloidal particle fluxes in the SOL. The absolute E(~) fluctuation levels show dependence on the sign of Er shear. The modification of the microscale turbulence by the poloidal Er x B rotation shear EB at the L - H transition near LCFS is also studied by X-mode fluctuation Reflectometry. The new data were obtained by spatial spectroscopic technique.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France

Implementation of correlative enhanced scattering diagnostics of small scale plasma turbulence at the FT-2 tokamak

In this paper the first results of implementation of CES diagnostics at the FT-2 tokamak possessing much more developed set of standard tokamak diagnostics are presented

Study of the radiative decay ϕ→ηγ\phi \to \eta \gamma with CMD-2 detector

Using the $1.9 pb^{-1}$ of data collected with the CMD-2 detector at VEPP-2M the decay mode $\phi \to \eta \gamma$, $\eta \to \pi^+\pi^-\pi^0$ has been studied. The obtained branching ratio is B($\phi \to \eta \gamma) = (1.18 \pm 0.03 \pm 0.06)$.Comment: 13 pages, 5 figures, LaTex2e, to be published in Phys. Lett.

Study of the Process e+ e- --> omega pi0 --> pi0 pi0 gamma in c.m. Energy Range 920--1380 MeV at CMD-2

The cross section of the process e+ e- --> omega pi0 --> pi0 pi0 gamma has been measured in the c.m. energy range 920-1380 MeV with the CMD-2 detector. Its energy dependence is well described by the interference of the rho(770) and rho'(1450) mesons decaying to omega pi0. Upper limits for the cross sections of the direct processes e+ e- --> pi0 pi0 gamma, eta pi0 gamma have been set.Comment: Accepted for publication in PL