Science of materials and mechanical Engineering

Hydrodynamics of Stream Flows in Cracks of the Managed Hydrostatical Spherical Hinges

In this paper, we propose the construction of hydrostatical spherical hinge with the stream system of adjusting the sphere position. Also, we consider the flow features in the flowing part of hinge. The method of calculating the hydrodynamic parameters of stream flows in cracks of hydrostatical supports enables studying the hydrostatistical spherical hinges. Moreover, we determine the fields of speeds, pressures, tensors of tensions and tensors of deformation speeds in the whole volume of the crack of hydrostatical supports.

The Effect of Anisotropy of the Microstructure Reinforced Boride Ceramics on the Adhesive Bonding Strength of Titanium Nitride Coatings

In this article, firstly we investigated the contact interaction of the tool material made of reinforced boride ceramics and covered with titanium nitride with a diamond indenter with various loads. We studied the influence of the microstructure nature of ceramic and loading conditions on the adhesion strength of the titanium nitride coating. We determined that the magnitude of the friction force depends on the surface microstructure of the composite material.

The Calculation of Fatigue Lifetime of Constructional Aluminium Alloys under Asymmetric Tension-Compression Loading by the Method of Equivalent Stress

The paper considers the problem of calculating the fatigue lifetime and creating the S-N curves of constructional aluminium alloys under high-cyclic asymmetric tension-compression loading. The solution is based on the equivalent stresses conception. Also, we calculate the lifetime of constructional aluminium alloys. Our results satisfactorily conform to the experimental data obtained. These methods can be further employed to calculate fatigue lifetime of any constructions’ elements working under the asymmetric tension-compression.

The Cooling Process of the Polymeric Film on the Drum Partially Submerged in the Water Bath

In this paper, we develop the design procedure of the polymeric film cooling on the cooled drum partially submerged in a water bath. The process specificity of the process lies in the fact that after the films removal from a drum its surface hasn’t time to cool down to its initial temperature. We propose the mathematical model of cooling which allows calculating the film temperature field and the drum shell ring on their thickness depending on the angular coordinates cylindrical.

Reasoning of the Use of Roller Dampers in an Extended Frequence Rangeт

The paper defines constraints in the form of inequalities for the minimal value of the coefficient of sliding friction ƒ  between the interacting elements of roller dampers, which set the boundaries, where pure rolling of roller or ball in the spherical cavities of their bodies can be implemented. We analytically justify the use of roller dampers in a wide frequency range both at 0<ω0≤1,6  rad/s, and at ω0>1,6 rad/s using as an example of roller and ball absorbers.

Quality Monitoring of Welding by Electric Characteristics of the Process

This article presents the analysis results of existing methods of monitoring the quality of welded joints by electric parameters of the arc. Their advantages and disadvantages are described. We show that there is a need to use a large number of related parameters when creating automatic systems for monitoring the quality of welded joints by electrical parameters of the process. It requires a complex math-based environment. The systems of artificial intellect can be used as such an environment.

Controlling the Converter Melting by Energy-Saving Technology

Based on the theoretical justification of carbon oxidization and the analyses of progressing processes of heat generation, we develop the model of temperature condition of the converter frame bath. We analyze the existing methods of controlling the converter process by the energy-saving technology. We also study the influence of the distance lance to the level of quiet metal bath on thermal characteristics. We analyze control methods of the energy-saving technology for the blowing converter by single- and two-circuit lances.

Principles of Compaction Powder Antifrictional Material Based on Dispersion-Hardened Copper

The paper studies the influence of antifriction materials based on dispersion strengthened copper powders with alloying additions of graphite and iron on the process of pressing and subsequent sintering. We examine the influence of pressure, temperature and sintering time on structure and sealing material in order to optimize them. We propose the equation for an analytical description of materials compaction. We show that the plastic deformation of the components of the original charge lie in the base of the compaction process.

The Reliability of the Phenomenological Damage Accumulation Models under Complex Stress State

This paper verifies and determines the reliability and limits of using modern phenomenological models of sparse damages accumulation in structural materials under complex stress state. We conduct the experiments of various metals and provide the data of verifying damage models under tension and torsion for aluminium alloy Д16Т, steels 12Х18Н10Т and 30ХГСА. We analyze four theoretical models (Lemaitre, modified Lemaitre, Bonora, Chandrakanth) and present the experimental evaluation procedure of the damage parameters.

The Influence of Annealing Conditions on Structure and Magnetic Properties of Nanodimensional Fe50Pt50 Film on Planar SiO2(100 nm)/Si(100) Substrates

In this paper, we study the influence of 3-nm-thick Ag intermediate layer and annealing duration in a vacuum at the temperature of 600°С on formation of chemically ordered L10(FePt) phase in the nanodimensional film composition (NFC) of Fe50Pt50(15 nm)/Ag(3 нм)/ Fe50Pt50(15 nm) on the planar SiO2(100 нм)/Si(100). substrate. Its structure and magnetic properties are investigated. We show that the formation of L10(FePt) phase takes place during annealing whose duration is 30 мин. min.