Papers by Keyword: Titanium

Abstract: The three-layer composite AMg6–AD1–VT1-0, obtained by explosion welding, is widely used as transition elements in the creation of critical structures made of titanium and aluminum alloys. In welded joints of dissimilar metals, which are limited soluble in each other and form intermetallic compounds, mutual diffusion can occur at elevated temperatures, and when the concentration corresponding to the limit of solubility at a given temperature is reached, conditions are created for the nucleation and growth of intermetallic phases. When studying the effect of heat treatment on the properties of welded joints of such metals, it is necessary to take into account the structure, properties and features of the formation of intermetallic phases, as well as the factors that contribute to their appearance and intensive growth. The latter include hardening, obtained by the composite material after blasting and further technological operations, associated with pressure treatment, which accelerate the diffusion processes, due to fragmentation and development of the block structure.

Abstract: In this work, the wear resistance of hardened simultaneous diffusion saturation on S235J0, C45, 55NiCrMoV6, C80W1 and X162CrMoV12 steels with boron, chromium and titanium and rigidly fixed abrasive Al2O3 particles were investigated. Wear was determined by measuring the loss of mass every 30 seconds of the test. Full wear of the layer occurred in 10 minutes with a load on the sample of 9.5 MPa. According to the test results, it is found that the wear resistance of alloyed steels increases as the content of alloying elements and carbon increases, but this increase is not unambiguous because of a decrease in the thickness of the diffusion layer as the degree amplification of alloying steels. Taking into account the economic parameters, such as the cost of steel, the cost of manufacturing products, we can conclude that the greatest economic effect shape can be achieved when using the hardening steels with a carbon content of 0.5 mass percent and the total content of alloying elements up to 5 - 7 mass percent.

Abstract: This work described the technology of boronizing of titanium Grade2 from the generation of the gas phase directly in a sealed container during the decomposition reactions of the powder saturating medium. With such an implementation of the process in a closed volume, waste gas neutralization devices are not required, since the generation and decomposition of active saturating gases occurs in a closed volume. At saturation of titanium from the gas mixture, titanium borides, titanium nitrides, as well as titanium and chromium carbides can be produced in the coating. The microhardness of the coating is 2800–3200 HV0.1. The thickness of the diffusion coatings in this case can be up to75 microns. It is indicated that diffusion coatings on titanium by this technology should not exceed a thickness of more than 100 microns, and if the thickness of the diffusion coating exceeds 100 microns, the risk of chipping will increase.

Abstract: The main purpose of this paper is to analyze the temperature in turning process of a titanium bar, both with noncontact infrared thermometer and thermocouple. In order to have a comparative appreciation of the difference between the temperature measured with contact and noncontact methods, the determinations are graphically represent separately and on the same figure.

Abstract: In this study the effect of the Titanium and aluminum powder addition on microstructure and mechanical properties of AISI 430 ferritic stainless steel welds produced by gas tungsten arc welding was investigated. It’s observed that the addition of aluminium (Al) or titanium (Ti) reducing the grains size, increase the equiaxed grains fraction and improve the mechanical properties with varying degrees. While the addition of mixture (Al+Ti) leads to better improving in mechanical properties and reducing of grains size up to 85 %. The details of tensile tests, optical microscopic observations, microhardness, tensile test and Scanning electron microscopy (SEM) fractography, are discussed.

Abstract: A new method of linear connected joints (Ti/CF-plug/Epoxy) of Ti (Titanium) to Epoxy connected by CF-plug was innovated and developed, since fine carbon fibers (CFs) generate the extremely large friction force by their broad interface between metals and Epoxy polymer (M/Epoxy). Compared with glue and spontaneous adhesions of M/Glue/Epoxy and M/Epoxy, the new method remarkably improved the fracture toughness with maintaining light weight. To maintain the high joint strength of the Ti/CFW-CFJ/Epoxy, the Ni coating film on CF should control to bite the CF by molten Ti. The tensile strength (σ_b) and its strain (ε_b) of Ti/NiCFW-CFJ/Epoxy were higher than those of Ti/CFW-CFJ/Epoxy. In addition, increasing the CF-volume increases the σ_b. The CF-plug joint between Ti and Epoxy matrix CFRP apparently probably enhances the fuel efficiency, as well as safety level of airplane.

Abstract: Bioactive coatings have predominately been explored through plasma spray; but this technique has associated heat and melting of the feedstock materials thereby degrading the novel bioactive properties of hydroxyapatite (HA), as well as deteriorating the adhesion of the coating to the implant. The current study discusses a novel approach to producing biocompatible coatings that have been deposited at temperatures well below their melting point. The cold spray process was used to deposit 100 wt.% titanium (Ti) and composite powders with 80 wt% titanium (Ti) and 20 wt% hydroxyapatite (HA) onto Al6061, 316SS and Ti-6Al-4V substrates with the aim of achieving well-bonded homogeneous coatings; the effect of process parameters and substrate material was investigated. Preliminary results indicate the phase composition of the HA remained the same before and after synthesis of coating. Dense composite coatings were obtained with thicker coatings yielding the least amount of total porosity.

Abstract: This paper aims to comparison of corrosion properties of two titanium alloys with different grain size. These alloys are commonly used in implantology for manufacturing long term body hard tissues replacements. Surfaces of tested samples were also electrochemically anodized using fluorine ions rich environment: the main reason for anodization was to create surfaces with highly bioactive properties which can intensify healing process and result into better bonding between body tissues when they are used in implantology. It was found by direct electrochemical methods that difference of corrosion rate between anodized and non-anodized samples was not significant. Anodization results positively influenced decreasing of corrosion rate when samples were tested in aerated physiological solution (0,9 wt. % NaCl/water). Type of bonding between implant and surrounding tissue may be also predetermined by value of contact angle of tested sample and water droplet on its surface. This paper confirmed that anodization increases wettability of tested samples and lower the contact angle to ~60°. According to these results anodization process may be recommended as a profitable treatment for surfaces of tissue replacements made from titanium.

Abstract: The oxide layers on titanium were formed by plasma electrolytic oxidation technique in acid aqueous electrolytes containing sodium tungstate and copper acetate. The coatings with WO₃-CuO or WO₃-CuWO₄ oxide layers have been formed in the electrolytes with H₂C₂O₄ (pH~6) or H₂SO₄ (pH~4) accordingly. The coatings with WO₃-CuWO₄ have a developed surface architecture. The surface is constructed from coral-like structures with lamellar nanocrystals containing copper tungstate and tungsten oxide. The layers of tungsten oxide nanocrystals occupy the depressions between these structures. The band gap of the mixed WO₃CuWO₄ oxide layers is 2.8 eV.

Abstract: During the operation of thermal power plants, boilers, incinerators, vehicles, industrial enterprises for the production of synthetic fatty acids, building materials, paints, textiles, cardboard, paper, as well as resins and products based on them – plywood, chipboards, wood-fiber boards, plastics, etc. The environment is contaminated with formaldehyde. Formaldehyde acts climatically and toxically on local, regional and global processes in the environment and contributes to a high level of air pollution (air pollution index > 14) in almost all industrialized regions of Russia. Products containing formaldehyde, getting into residential and non-residential premises, create an environmental risk to public health. The article is devoted to determining the effect of formaldehyde on woody plants by biochemical and electrophysiological methods and developing a method of reducing the concentration of formaldehyde in the environment by introducing into industrial materials aluminosilicate sorbents of different crystal chemical structure, processed thermo-, in a pulsed magnetic field and under the combined effect of a pulsed magnetic field and temperature effects.