Papers by Keyword: Titanium Carbide

Abstract: The surface improvement of light-weighted metals by adding of hard ceramic particles into a metal matrix has promised to be perspectives for aerospace industry. In the present study, titanium carbides of nano size were incorporated to the titanium substrate by a selective laser melting (SLM) of Ti + (10, 15 and 20 wt.%) TiC powder mixtures via an Ytterbium fiber laser with 1.075 mm wavelength. Optimal regimes of the 3D laser additive process were determined. We studied how the interfacial properties would change due to the difference in composition in case of the titanium matrix nano composites (TMNC) reinforced with carbides. The phase analysis of the fabricated TMNC showed that the initial carbide particles are dissolved after the remelting with different velocities. A particular attention was paid to the carbide dilution and secondary carbides formation mechanisms when the TiC was mixed with titanium. Various parameters, such as microstructure, phase constitution and mechanical properties of the gradient TMNCs were investigated by means of OM, SEM, XRD and microhardness measurement. It was shown that the microstructure had two types of heterogeneity: the TiC particles at the interlayer interfaces and element chemical segregation on the boundaries of the tracks.

Abstract: Photocatalyst coatings on alumina (Al₂O₃) balls had been successfully fabricated by mechanical coating technique, with titanium carbide (TiC) powder and subsequent heat treatment in carbon powder. The effect of heat treatment conditions in carbon powder on the formed compounds, surface morphology and photocatalytic activity of photocatalyst coatings was investigated. XRD results show that the formed compounds change with increasing the heat treatment temperature in carbon powder, and rutile TiO₂ on the surface of TiC coatings at 1073 K and 1173 K. The generated oxygen vacancies confirmed by XPS measurement, are in favor of narrowing band gap to enhance the visible-light photocatalytic activity of photocatalyst coatings. The photocatalytic activity of photocatalyst coatings has been effectively enhanced, and the samples fabricated at 1073 K and 1173 K for 2 h show higher activity. The fabrication strategy provides us a facile preparation procedure of visible-light responsive photocatalyst coatings.

Abstract: Structure of carbon modifications, obtained via pyrolysis of vegetable feed, and ash content of natural graphite are crucial factors during mechanochemical synthesis of titanium carbide under vibratory conditions. The possibility of synthesis of titanium carbide with minimal sulfur content has been shown.

Abstract: The phase composition, microstructure and morphology of composite powders «TiC-HSS steel binder» obtained by the SHS method in layerwise combustion mode have been studied. Titanium powder, carbon (carbon black) in a ratio corresponding to equiatomic titanium carbide and high speed steel as a thermally inert binder was used as a reaction mixture. It was found that the mass transfer of reaction mixture components between the carbide and metal binder was taking place during synthesis, as a result of which the final phase and elemental composition of the synthesis products was formed. It is shown that the volume content of thermally inert binder significantly affects the dispersion of the formed carbide phase.

Abstract: In present study, the effects of the process parameters on chlorination of Titanium Carbide (TiC) was studied. Besides that, process parameters were investigated by using experimental design of experiment (DOE) and statistical analysis. The chlorination of the samples was carried out at temperatures between 400 to 500°C. Effects of three parameters, namely temperature, soaking time, and molar ratio of potassium permanganate (KMnO₄) to hydrochloric acid (HCl) were investigated. The interaction, on the rate of chlorination of TiC were statistically evaluated by using DOE. The weight loss (wt. %) was the main response taken into account in this paper. The results of the experimental design indicated that the main significant factor for chlorination of TiC was higher temperature, soaking time and higher molar ratio of KMnO₄ to HCl. DOE results have demonstrated that the highest extent of chlorination obtained at the highest weight loss (wt. %) was about 54.59 wt. % at 500°C with a soaking time of 180 minutes and KMnO₄ to HCl molar ratio of 0.17 respectively. The amounted to a titanium extraction of about 96.39 %. On the other hand, the lowest wt. lost was 30.76 wt. % and this was obtained at 500°C for 120 minutes with KMnO₄ to HCl molar ratio of 0.09 respectively. The results obtained from this work will be employed as a guide for the future studies on chlorination of nitrided/carburized Malaysian ilmenite or titanium oxycarbonitride. The final aim was to produce TiCl₄ at low temperatures (≤500°C) using the latter samples. The experimental values are in good agreement with calculations from the statistical model.

Abstract: Titanium carbide has been attractive for years an engineering ceramics due to its high hardness, high melting point, and good chemical stability. Similarly, titanium dioxide has excellent anti-microbial ceramic material by photon energy. In this study, the anatase type titanium dioxide layer prepared by oxidation of the titanium carbide powder by high temperature oxidation in air atmosphere was investigated in order to determine the possibility of its photocatalyst materials by radiant energy. TiC powder samples of different grain size were gained by ball mill. These samples were oxidized at room temperature to high temperature. The samples exhibited a steady mass gain with increasing oxidation temperature. Based on the results of the X-ray diffraction analysis, anatase type TiO₂ was detected on the titanium carbide samples. It is considered, the titanium carbide showed convension anatase type titanium dioxide layer produced by oxidation.

Abstract: The aim of this study was an investigation of the influence of technological parameters of the process of self-propagating high-temperature synthesis (SHS) on the formation of nanoparticles of titanium carbide from a mixture of powders of titanium and carbon in molten aluminum and on the properties of the obtained composite Al-10 wt. %TiC. The results show that the application of such techniques as the use of titanium powder of coarse fraction, the integrated flux of composition 30-35% NaCI, 52-57% KCI, 10-13% Na₂SiF₆ and adding aluminum powder to the initial charge can reduce the size of most of the synthesized particles of the carbide phase TiC to ultrafine sizes. At the same time, the replacement of 20% titanium metal powder in the charge with the titanium-containing salt Na₂TiF₆ makes it possible to synthesize nanoparticles of titanium carbide with size less than 0.1 μm in the composite Al-10%TiC. The produced SHS composite Al-10%TiC is characterized by a high level of physico-mechanical and tribological properties with good corrosion resistance. Reinforcement with ultrafine and nanosized particles of TiC enhances the strength characteristics of the composite Al-10%TiC by 2.5-2.9 times in comparison with pure aluminum, while the reinforcement with microsized particles of TiC (2-4 μm) only by 1.5-1.7 times; resistance to corrosion increases by 4-5 times.

Abstract: The paper presents the result of studies of composite powders produced by self-propagating high temperature synthesis (SHS) in the reaction mixtures of titanium, carbon and high chrome cast iron, and electron-beam coatings based on them. It was found that the morphology and dispersion of titanium carbide particles in the SHS-product were determined by cast iron powder content in the reaction mixtures. The effect of content of the SHS powders on the characteristics of electron-beam coatings, including abrasive wear resistance of facing coatings was shown.

Abstract: A structure of Ti-TiC coatings with different content of titanium binder, overlaid of composite powders, which were obtained by self-propagating high-temperature synthesis, was investigated. The structure was studied by X-ray analysis and metallography. A size of the carbide particles in coatings, hardness of coatings and rate of wear were measured.

Abstract: The present study aimed to investigate the exploitation of Concentrated Solar Power (CSP) for the in-situ production of anti-wear TiC-based surface layers onto steel substrates. For this purpose, “solar” experiments were carried out at the installations of Plataforma Solar de Almería (Spain). TiC powder was pre-deposited onto carbon steel substrates that have been subsequently exposed to concentrated solar irradiation for various dwell time values. The temperature field developed at the specimens’ surface during solar exposure was recorded in real-time by the aid of an optical pyrometer. Microscopic observations revealed the characteristic microstructure features of the hardfacing surface layers obtained and preliminary dry sliding tests performed in a pin-on-disc apparatus, allowed to estimate their machinability using conventional cutting tools.