215 research outputs found

    Composición y edad de fragmentos de monacita de sedimentos terrígenos jurásicos superiores en la base de formación de bazhenov (área multan, siberia occidental)

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    La Formación Bazhenov es considerada como el principal estrato petrolero que es madre de casi todos los campos de la megacuenca petrolera de Siberia occidental. Por ahora es una de las formaciones más estudiadas de Siberia y, quizás, de Eurasia. Aúnque hay una cantidad enorme de estudios dedicados a la formación Bazhenov, no hay estudios mineralógicos detallados en el nivel moderno de hardware. Tampoco se han estudiado la edad y los fuentes de los materiales terrígenos de la formación. Hemos explorado la monacita detrítica de los sedimentos terrígenos jurásicos superiores del Área Multana en la base de la formación Bazhenov en el centro de Siberia Occidental, Distrito de Surgut. Todo el fosfato detrítico de la tierra rara pertenece al tipo cerio y se refiere como monacita-(Ce). El mineral es bastante disimilar en cuanto a sus propiedades químicas, especialmente a su contenido de torio. Unos fragmentos han estado sometidos a cambios superpuestos secundarios. Se redondea la monacita detrítica a grados diferentes lo cual es un indicador de varias distancias de la inundación del yacimiento de fosfato de la tierra rara. Según los datos químicos, la mayoría de la monacita ha sido lavado de las rocas mediana y básicas (probablemente, alcalinas y subalcalinas) así como de las rocas siálicas (granitoidas y capas asociadas). Según datación química, la mayoría de los pedazos monazíticos han sido lavado de las formaciones Proterozóicas muy viejas y rocas Proterozóicas tempranas. Los materiales terrígenos se derivan probablemente de los conjuntos rocosos de los márgenes sudoriental y oriental de la megacuenca de Siberia Occidental, tales como la Cresta Proterozóica de Yenisei o los conjuntos de rocas Proterozóicas Tempranas de la Falla de Altay y Sayan

    Composición y edad de fragmentos de monacita de sedimentos terrígenos jurásicos superiores en la base de formación de bazhenov (área multan, siberia occidental)

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    Bazhenov Formation is regarded as the main oil-bearing stratum mothering nearly all the fields of the Western Siberia Oil-Gas-bearing Megabasin. Presently, it is one of the most studied formations of Siberia and, probably, Eurasia as a whole. While there is an enormous amount of studies devoted to the Bazhenov Formation, there are no detailed mineralogical studies at the modern hardware level. The age and sources of the terrigenous materials of the formation have not been studied as well. We have explored the detrital monazite from the upper-Jurassic terrigenous sediments of the Multan Area at the foundation of the Bazhenov Formation in the central part of Western Siberia, Surgut District. All the detrital rare earth phosphate is of the cerium kind being a monazite-(Се). The mineral is rather dissimilar in respect of its chemical properties, especially, the content of thorium. Some fragments have been subjected to superposed secondary changes. The detrital monazite is rounded to various degrees which is indicative of the various distances from the rare earth phosphate orebody washout. As per the chemical data, most of the monazite has been washed out from the medium and basic rocks (probably subalkaline or alkaline) as well as the sialic rocks (granitoids and associated veins). According to the chemical dating, most of the monazite fragments have been washed out of the very ancient Proterozoic formations and lower-Proterozoic rocks. Terrigenous materials derives probably from the rock assemblages of the eastern and south-eastern fringes of the Western Siberian megabasin such as the Proterozoic Yenisei Ridge or Lower-Proterozoic blocks of the Altay and Sayan Faulting.La Formación Bazhenov es considerada como el principal estrato petrolero que es madre de casi todos los campos de la megacuenca petrolera de Siberia occidental. Por ahora es una de las formaciones más estudiadas de Siberia y, quizás, de Eurasia. Aúnque hay una cantidad enorme de estudios dedicados a la formación Bazhenov, no hay estudios mineralógicos detallados en el nivel moderno de hardware. Tampoco se han estudiado la edad y los fuentes de los materiales terrígenos de la formación. Hemos explorado la monacita detrítica de los sedimentos terrígenos jurásicos superiores del Área Multana en la base de la formación Bazhenov en el centro de Siberia Occidental, Distrito de Surgut. Todo el fosfato detrítico de la tierra rara pertenece al tipo cerio y se refiere como monacita-(Ce). El mineral es bastante disimilar en cuanto a sus propiedades químicas, especialmente a su contenido de torio. Unos fragmentos han estado sometidos a cambios superpuestos secundarios. Se redondea la monacita detrítica a grados diferentes lo cual es un indicador de varias distancias de la inundación del yacimiento de fosfato de la tierra rara. Según los datos químicos, la mayoría de la monacita ha sido lavado de las rocas mediana y básicas (probablemente, alcalinas y subalcalinas) así como de las rocas siálicas (granitoidas y capas asociadas). Según datación química, la mayoría de los pedazos monazíticos han sido lavado de las formaciones Proterozóicas muy viejas y rocas  Proterozóicas tempranas. Los materiales terrígenos se derivan probablemente de los conjuntos rocosos de los márgenes sudoriental y oriental de la megacuenca de Siberia Occidental, tales como la Cresta Proterozóica de Yenisei o los conjuntos de rocas Proterozóicas Tempranas de la Falla de Altay y Sayan

    Electro-explosive alloying of VT6 alloy surface by boron carbide powder with the subsequent electron-beam treatment

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    The formation of electro-explosive alloying zone with the thickness up to 50 µm has been revealed. It has been shown that it has a gradient structure, characterized by the decrease of carbon and boron concentration with the increase of the distance up to the treatment surface. The subsequent electron-beam treatment of alloying zone leads to flattening of alloying surface relief and is accompanied by the formation of a multilevel structure at the depth up to 30 µm, characterized by the interchange of some layers with a different level of alloying, having structure of a submicro- and nanoscale level

    Structure-phase states of silumin surface layer after electron beam and high cycle fatigue

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    Modification of eutectic silumin surface has been implemented by high-intensity pulsed electron beam. The irradiation mode has been revealed; it allows increasing silumin fatigue life in more than 3.5 times. It has been established that the main reason of this fact is the formation of a multiphase submicro- and nanosized structure. It has been elicited that the most danger stress concentrators are large silicon plates situated on the surface and near-surface layers

    Formation Wear Resistant Coatings on Martensite Steel Hardox 450 by Welding Methods

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    By methods of modern physical materials science the investigations analysis of phase composition, defect substructure, mechanical and tribological properties of Cr-Nb-C-V containing coatings formed in surfacing on martensitic wear resistant steel Hardox 450 were carried out. It was shown that surfacing resulted in the formation of high strength surface layer 6 mm in thinness. This layer had wear resistance 138 times greater than that of the base and friction coefficient 2.5 times less. Having analyzed the deflected mode of the deposited material in conditions of friction, a conclusion is drawn that plastic shear deformation is localized in the surface layer due to the high friction factor, as the result, scratches are formed. The maximum of tangential stress is deflected deep into the material provided that friction factor is low. On the basis of the investigations by methods of X-ray structural analysis and transmission diffraction electron microscopy it was shown that increase strength and tribological properties of surfacing metal were caused by its phase composition and state of defect substructure, namely, availability of interstitial phases (more than 36%) and martensitic type of a-phase structure

    Fatigue life of silumin treated with a high-intensity pulsed electron beam

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    The regularities of the formation of the structure of silumin irradiated with a high-intensity electron beam in different modes are revealed using optical and scanning electron microscopy. The optimum irradiation mode that allows one to increase the fatigue life of this material by a factor of up to 3.5 is determined. The probable causes of the observed effect are investigated

    Fatigue variation of surface properties of silumin subjected to electron-beam treatment

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    The analysis of structure-phase states modification of silumin subjected to electron beam treatment with the following fatigue loading up to the failure is carried out by methods of transmission electron diffraction microscopy. The tribology and strength properties of silumin surface after electron beam treatment and fatigue tests are studied and hardness decrease, wear coefficient and friction coefficient increase with the growth of cycles number are revealed. The possible reasons of the tribology and strength properties of silumin surface layers decrease are discussed

    Formation of the surface alloys by high-intensity pulsed electron beam irradiation of the coating/substrate system

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    The results of the analysis of the structure and properties of the surface layer of aluminum A7 subjected to alloying by the intense pulsed electron beam melting of the film / substrate system. Fold increase in strength and tribological properties of the modified surface layer due to the formation of submicro - nanoscale multiphase structure have been revealed

    Fractography of Fatigue Fracture Surface in Silumin Subjected to Electron-Beam Processing

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    The surface modification of the eutectic silumin with high-intensity pulsed electron beam has been carried out. Multi-cycle fatigue tests were performed and irradiation mode made possible the increase in the silumin fatigue life more than 3.5 times was determined. Studies of the structure of the surface irradiation and surface fatigue fracture of silumin in the initial (unirradiated) state and after modification with intense pulsed electron beam were carried out by methods of scanning electron microscopy. It has been shown, that in mode of partial melting of the irradiation surface the modification process of silicon plates is accompanied by the formation of numerous large micropores along the boundary plate/matrix and microcracks located in the silicon plates. A multi-modal structure (grain size within 30-50 μm with silicon particles up to 10 [mu]m located on the boundaries) is formed in stable melting mode, as well as subgrain structure in the form of crystallization cells from 100 to 250 [mu]m in size). Formation of a multi-modal, multi-phase, submicro- and nanosize structure assisting to a significant increase in the critical length of the crack, the safety coefficient and decrease in step of cracks for loading cycle was the main cause for the increase in silumin fatigue life

    Formation of a microcomposite structure in the surface layer of yttrium-doped titanium

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    Surface layers containing oxides and carbides of titanium and yttrium are prepared by the electroexplosive doping of titanium with yttrium. The subsequent electron-beam irradiation leads to dispersion of the structure to a nano- and submicron state. The formation of two types of eutectics is revealed using scanning electron microscopy. The eutectics enriched in titanium and yttrium have a globular and plate-like shape, respectively. The formation of a modified surface layer (enriched in yttrium, carbides and oxides of titanium and yttrium) leads to a threefold increase in the microhardness of the titanium, a more than twofold decrease in the friction coefficient of the doped layer, and a more than 2.8-fold decrease in the wear rate
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