Science of materials and mechanical Engineering

Influence of Temperature-Temporal Parameters of Fusion Treatment and Cooling Speed on Structure and Mechanical Properties of Alloys of АМг6л and АМг11

The paper establishes the influence of temperature-temporal parameters of fusion treatment in the liquid state and cooling speed during crystallization on the structure and mechanical properties of АМг6л and АМг11 casting alloys. Melting is conducted in the resistance stove in graphite crucible. We use the following materials: aluminum of А99 type and such ligatures as Al–Mg, Al–Zr, Al–Be, Al–Ti, Al–Si. Metallic fusions of the explored alloys are kept at various temperatures and self-control time and poured out in different kinds of molds.

Finite-Element Study of the Bone Anisotropy and Inhomogenity Influence on Stress Distribution in Mandible

The paper discusses simulation results of mathematical modeling of the stress-strain state of the lower jaw with advanced three dimensional finite element model. To simplify the study of the structure of the elastic constants of anisotropic inhomogeneous body bone we use a priori data on characteristics of the rigidity of its cortical layer.

The Velocities Field Analysis of Fluid Flow Rotating in a Cylindrical Tank

The paper presents results of velocity fields experimental measurements of a fluid rotation in a spacecraft cylindrical tank. We propose the analytical expressions for distributions of the azimuthal velocity and the data collection for calculating the fluid power affects on the tank walls. We approximate the results of hot-wire measurements of the velocity vector components and build the structure of semi-empirical relationships when developing the physical model of inner flows.

Synthesis and Investigation of Electronic Structure of Ca-HAP Modified with Carbon Nanomaterials

In this paper, we synthesize the series of Ca-HAP–carbon nanomaterials composites. We use various synthesis methods – mechanical mixing and mixing in aqueous suspension with ultrasonication (original calcium hydroxyapatite powder was synthesized by deposition method from basic aqueos solution). We utilize carbon nanotubes, fullerenes (C60) and shungite as modifying materials. By X-ray photoelectron spectroscopy we investigate the electronic structure of samples. We also conduct the infrared spectroscopy examination of samples.

Influence of Annealing Temperature on Structure and Magnetic Properties of Nanodimensional Fe50Pt50(15 нм)/ Ag(30 нм)/Fe50Pt50(15 нм)/SiO2(100 нм)/Si(001) Film Composition

We study the influence of annealing temperature in range of 300–900 °С and intermediate Ag layer on processes of diffusional phase formation and transition of chemically disordered magnetic-soft А1(FePt)FCC phase to chemically ordered magnetic-hard L10(FePt)FCT phase in nanodimensional Fe50Pt50(15 nm)/Ag(30 nm)/Fe50Pt50(15 nm) film composition (NFC) on SiO2(100 nm)/Si(001) substrate. We investigate its structure, morphology and magnetic properties. We show that after deposition in NFC under study the phase А1(FePt)FCC is observed.

Temperature Dependence of Mechanical Properties of Eutectic (α-Al + Mg2Si) Alloys

We investigate mechanical properties of complex alloys with eutectic (α-Al–Mg2Si) structure for high-temperature application. Specimens are annealed at the temperature of 300°С during 5 hours to obtain uniformly distributed dispersed Al3(Sc1–xZrx) nanoparticles in α-Al phase. Investigation of mechanical properties of alloys with different content of eutectic component by a tension method is carried out in the interval of temperatures 20–400°С with speed of 103s1. The content of eutectic compound is determined by metallographic method.

The Current State of Production Capacities of Metallurgical Industry in Ukraine

The paper presents the analysis of the current state of the metallurgical industry in Ukraine and highlights key problems of its revival in the post-crisis period. Most of domestic steel enterprises use outdated technologies such as open-hearth production and blooming. In addition, the equipment depreciation in average is about 65 %. It hinders Ukrainian steel producers to successfully compete in domestic and foreign markets. A significant drawback of the current state of the industry is limited government backup and impact on its development.

Predicting Temperature Regime of Melting Furnace Bath

Based on the system approach of the phenomena of heat transfer in a furnace, we obtain relations of kinetics of transition change rate of bath temperature field from the load in the solid metal charge. We uncover the general form of the power expression of the wave process in the bath without integrating differential equations using the experimental data, the ratio of similarity theory, as well as physical modeling. In addition, we obtain criterion equations of heat transfer at fully developed turbulent flow for the internal problem.

Finite User Element for Modeling the Processes of Multilayer Structures Delamination in ABAQUS

Based on relations of the iterative analytical theory, we develop and numerically apply the stratified 8-nodes finite user element (USER IAT FE) in the ABAQUS environment. The final element allows effectively investigating the processes of nonlinear deformation and failure of spatial multilayer design. Finite element models constructed on the basis of the developed stratified 8-nodes finite user element have persistent rates of solutions convergence both for three-dimensional bodies, thin plates and shells.

Ferromagnetic Resonance in Nanoscaled Fe-Pt Films

The paper under scrutiny studies the influence of phase composition and structure of nanoscaled 10 and 30 nm FePt films on their magnetic properties, specifically on the shape change of ferromagnetic resonance (FMR) lines. The films are deposited on substrate of thermally oxidated (100 nm thick SiO2) monocrystalline Si with orientation of (001). Samples annealings are carried out in the vacuum of ∼1,3⋅10 −3∼1 Pа in the temperature range of 100–900 °С for 30 s at each temperature. FMR lines are obtained in magnetic field applied in the film plane after annealing at different temperatures.