Table of Contents

  • Transformation of heterophase inclusions “dispersed phases are in non-metallic matrix” in steels under laser action

    pg(s) 30-33

    Melting and crystallization of heterophase non-metallic inclusions “dispersed phases are in non-metallic matrix” was investigated. Mechanism of melting of the inclusions “dispersed phases are in non-metallic matrix” and inclusion-matrix boundaries under contact laser melting with steel matrix in the conditions of abnormal mass transfer connecting with formation of zones with high dislocation density and also with electron and electro-magnetic interaction between inclusion and steel matrix was proposed. That allows to create the possibilities for the influence on the inclusion-matrix boundaries and also on the chemical and phase composition of surface layer of non-metallic inclusions “dispersed phases are in non-metallic matrix”. Peculiarities of structure of non-metallic inclusions after speed crystallization were investigated. It was shown that under laser action the initial structure of inclusion-steel matrix boundaries transits into unstable equilibrium high-energy condition that cause development of the dissipation processes connecting with aspiration of system inclusionmatrix to the state with minimum of the free energy. In the result of the system inclusion-matrix transits to the state of unstable equilibrium which determines structure and properties of laser-quenched interphase boundary. Processes of melting, fusion and dissolution of nonmetallic inclusions “dispersed phases are in non-metallic matrix” and also of the melting of steel matrix play the great role in transformation of interphase inclusion-matrix boundaries under laser action.

  • Structure and magnetic properties of Mn1-xFexNiGe (0,05 ≤ x ≤ 0,60) solid solutions

    pg(s) 34-35

    Intermetallic alloys and solid solutions having magnetostructural phase transitions are of interest for theory and practice due to the presence of magnetoresistance, magnetocaloric and magnetostriction effects. MnNiGe-based alloys and solid solutions are convenient model objects for studying static and dynamic distortions of the crystal lattice, since magnetostructural transformations of both the first and second kind realized in them. The features of the relationship of magnetic properties and changes in the crystalline structure of Mn1-xFexNiGe (0,05 ≤ x ≤ 0,60) solid solutions are studied. It has been established that MnNiGe is an antiferromagnet with a Néel temperature TN ≈ 346 K. Substitution of Mn ions with iron ones causing a decrease in the parameters of the MnNiGe unit cell leads to the emergence of a ferrimagnetic state and in some cases to a manifestation of ferromagnetic ordering of magnetic moments.

  • Layered heat resistant (Nb–V) composites with intermetallic hardening, obtained by diffusion welding

    pg(s) 36-39

    The microstructure and characteristics of the heat resistance of layered composites of Nb–V alloys and intermetallic compounds with aluminum are presented. The composites obtained by diffusion welding under pressure of packages of aluminum foils and foils of niobium alloys with 5, 10, and 15 at. % vanadium had structures representing an alternation of viscous-plastic layers and reinforcing layers of aluminides. The composites were characterized by a viscous-plastic nature of fracture and higher values of strength at room temperature and temperatures up to 1300°C, in comparison with composites without vanadium.

  • Effect of TiB2 additives on sintering temperature, structure and properties of the composite material of the Fe- FeCr800 system

    pg(s) 43-45

    The effect of TiB2 additives on the sintering temperature, structure, and mechanical properties of materials based on the Fe-FeCr800 system is investigated. It was shown that the introduction of titanium diboride additives leads to the activation of compaction and to a 50–70ºС decrease in the sintering temperature of the pressed composites based on iron. It has been studied that the addition of titanium diboride in the range of 0.38-0.74 (% wt.) provides, with a slight increase in hardness, an increase of 20-25% of the flexural strength of the composite 65Fe-35 FeCr800800 (% wt.), and also provides the formation of a multiphase, microheterogeneous structure of the matrix-filled composite type, which consists of chromium steel of the X6Cr17 type, double iron-chromium carbides M7C3, M3C and complex carboborides of the Me3(CB) type.

  • The reciprocal lattice of cubical systems of metallic crystals

    pg(s) 46-49

    A study was carried out of the reciprocal lattice of metal crystals with cells I and F – Brave type. The X-ray diffraction pattern gives hkl for the F – unit cell for even values, and for I – for h k l = 2n (n is an integer). Transformation centered lattice to P − Bravais types choose that other reflexes do not die but they are absent in reciprocal lattice with metallic crystals are absent.

  • Influence of physicochemical and structural factors on cast materials – foundry methodology. Part I

    pg(s) 50-56

    A scientific methodology for foundry has been developed in order to have a constant connection between foundry and the continuous development of solid state physics. This is achieved through the continuous expansion of the minimum scientific knowledge based on the historical development of metal physics, solid state physics, and today mathematics is placed in the first place. Metal science is a pure application of metal physics and solid state theory based on foundry, today it is materials science. The natural mathematical theory of foundry is the theory of thermal conductivity describing phase transitions of the first and second kind through Stefan-type problems – solidification together with modern software products for descriptions.

  • Casting of body parts with complex geometry in 3D printed sand forms

    pg(s) 57-59

    The intensive development of turbochargers power at the end of the decade and two years after the announcement of the latest results of this development, “Breakthrough: Nitrogen Oxides (NOx) 10 times below the predicted for 2020 limits” still there is no data for the rehabilitation of the contemporary diesel engine. The progress made by the multiplication of turbochargers in bi-turbo, three-turbo and four-storied turbo has been underestimated and neglected in the shadow of the publicity for electric, hybrid and gasoline vehicles. The article offers progressive technical solutions for casting of aluminum crankcase for turbochargers of new generation through the rational use of 3D printed sand molds. The research and application in the foundry of new 3D printer technologies gives the opportunity to realize casting with new and additional functions due to their complicated geometry and their high geometric accuracy .

  • Technological first-order phase transition base of foundry and material science

    pg(s) 60-63

    Technological first-order phase transition is obtain base process of material science by numerical experiments at use of finite elements method (FEM). The history of movement and the geometry of the front in the first-order phase transition are investigated. A free first-order phase transition was investigated to estimate the local place of the liquid residue. Mathematical model is Stefan-Schwartz task in 3D case. The corresponding temperature fields of a free and technological first-order phase transition are presented. Engineering information is local phase transition conditions is shown of macro-level with the local transition time and volume at the front is assumed.

  • Complete set of radioisotope densitometer with ionising radiation source of cesium-137 and calibration of the radioisotope densitometers

    pg(s) 64-70

    Research on charging a radioisotope density meter (Endress + Hauser AG, Sweden) with ionizing radiation source of cesium-137 types GCs7.021.1, GC 7.012.8 and calibrating radioisotope densitometers on stands with liquid simulators based on mixtures of bromoform and ethyl alcohol. Calibrated radioisotope densitometers were used to determine the density of the pulp emulsion in the technological line of the State Enterprise «Navoi Mining and Metallurgical Combine» (Bessopan industrial site, Zarafshan sity, Republic of Uzbekistan). The paper presents studies on the development of a method for calibrating a radioisotope level meter (Berthold Technologies GmbH & Co. KG) under the conditions of the presence of natural radionuclides in the composition of gas condensate and powdered polyethylene intermediate product at the gas production enterprise of the JV «Uz-Kor Gas Chemical», «Ustyurt Gas Chemical Complex» (Kirk-kyz settlement, Republic of Karakalpakstan).