Magazine «Powder Metallurgy and Multifunctional Coatings. News ofHigher School»
Contents V. 3, 2011
POWDER PRODUCING PROCESSES AND PROPERTIES
Kontsevoi Yu.V., Ignatieva E.V., Ignatiev I.E., Pastukhov E.A.,Brodova I.G., Petrova S.A., Shirinkina I.G., Zakharov R.G.
Steel–aluminum lamellar composite with nanostructural interlayer
The given article presents the research results of the changes thatthe lamellar steel-aluminum compound structure undergoes depending on thedegree of deformation during rolling. Noticeable changes in the structure areshown to begin at a percent reduction of e > 75% or e > 1.54 in logarithmic units. The mechanism of plastic deformation of the fragile intermetallic layer isdescribed. It is shown that the viscoplastic intermediate steel-aluminumlamellar composite layer can be produced by rolling if the degree ofdeformation is raised to e=90%. Submicrocrystalline structure can be howeverobtained at e > 95% (e > 3).
Key words: laminated composite,intermetallic compound, intense plastic deformation, rolling, degree ofdeformation, nanostructure, structural fragmentation.
THEORY AND PROCESSES OF POWDER MATERIAL FORMATION AND SINTERING
Burkin S.P., Beketov A.R., Obabkov N.V., Brynskikh Ya.A., BabailovaA.N.
Analysis of molybdenum powder compactability during compaction andsintering
The effect of apparent density within a range of 0.10 to 98 g/cm3of molybdenum powder and concentration of plasticizers (solutions of glycerinein ethyl alcohol and natural pure rubber in gazoline) on compacting ability ofpowders in forming briquettes as well as during their vacuum sintering (1600°С) has been analyzed experimentally. The practicability of reducingcompaction and compacting pressure is found: the less is the apparent density,the more is reducing compacting ability and pressure. When the concentration ofplasticizer increases, the apparent density decreases and the compactioncoefficient grows in sintering. The experimental data obtained make it possibleto choose the proper parameters to produce fillets for provision of specifiedfinal sizes. It was also shown that the initial oxygen concentration in thepowder is decreased to allowable level during vacuum sintering at the expenseof introduction of natural pure rubber as a plasticizer at the rate of about0.5%.
Key words: molybdenum powder, formingbriquettes and fillets, plasticizer, compression ratio, sintering.
THEORY AND PROCESSES OF POWDER MATERIAL FORMATION AND SINTERING
Batienkov R.V., YeremeevaZh.V., Dorofeev V.Yu.
Investigation of hot forming process with molten phase based on Fe–Bpowder composition
The hot forming technique of powder Fe-B compositions in thepresence of liquid phase has been proposed. Introduction of 0.25 wt. % boron toiron powder is shown to improve the strength and abrasion indexes and thequality of interparticle joining.
Key words: powder charge mixture, hotforming, boron addition, liquid phase, wear resistance, strength, porouspowdered materials, crack resistance.
Self-propagating high-temperature synthesis (SHS)
SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS (SHS)
Kiryukhantsev-Korneev F.V., Kuptsov K.A., Sheveiko A.N., LevashovE.A., Shtansky D.V.
Wear resistant Ti–Al–Si–C–N coatings produced by magnetronspattering of SHS-targets
The results of investigation of hard wear-resistant nanostructuralcoatings in the Ti-Al-Si-C-N system, which are produced by the magnetronsputtering of multicomponent composite targets with various ratios of metal andnon-metallic components are presented. Coatings were applied in the reactionmixed gas at fixed values of substrate temperature and bias potential. Thecoating structure has been studied with X-ray phase analysis, optical emissionglow-discharge spectroscopy, SEM and REM. Mechanical and tribological propertieswere measured by indentation and scratch tests as well as tribological testsaccording to "rod-disc" schematic. The results of studies shows thatthe coating base consists of face-centered cubic phase on the basis of titaniumcarbonitride with average crystallites size of 2-20 nm, which is located in theamorphous matrix. The coatings of optimal composition have hardness of 40-50GPa, stable friction coefficient < 0.55, adhesion strength ≥ 50 N andwear rate <1·10–5 mm3/(N·m).
Key words: nanostructural coatings,magnetron sputtering, SHS-targets, hardness, friction coefficient, wearresistance.
SELF-PROPAGATING HIGH-TEMPERATURE SYNTHESIS (SHS)
Chukhlomina L.N., Vitushkina O.G., Avramchik A.N.
Interaction of nitrogen-containing ferrosilicon with zircon andilmenite concentrates in the SHS process
Equilibriums in the "ferrosilicon - zircon - nitrogen" and"ferrosilicon - ilmenite - nitrogen" systems have been calculated.The processes of nitriding these compositions were experimentally investigatedand the experimental and calculated data were compared. It has been establishedthat combustion in the "ferrosilicon - admixture - nitrogen" systems isinitiated when added zircon is no more than 60 % and ilmenite no more than 40%. The composition of reaction product for the mixture with zircon contains Si3N4,Fe, Si2N2O, and ZrO2 and with ilmenite: Si3N4,Fe, Si2N2O, and TiN. Lacking of ZrN in the first casecontradicts and presence of TiN in the last case corresponds to the calculateddata.
Key words: thermodynamic calculation,self-propagating high-temperature synthesis, ceramic composites based onnitride.
REFRACTORY, CERAMIC, AND COMPOSITE MATERIALS
Anisimov O.V., Kostikov V.I., Lobacheva E.V., Puzik V.I., ShtankinYu.V.
Development of aluminum based metallocomposites hardened byhigh-melting compound nanoparticles
The possibilities of liquid aluminum crystallization processapplication in the field of a centrifuge for creation of gradient compositematerials hardened by SiC dispersed particles as well as SiC and ZrO2 nanoparticlesare shown. It is found that introduction of preliminarily compacted mixtures ofAl and reinforcing component powders into the initial melt can result inuniform distribution of particles in the composite. Interaction of activateddispersed and nanodimensional SiC particles with aluminum matrix isestablished. In alloying Al powders by nanoparticles, deviation from classicalconcepts on dependence of matrix phase sizes, elastic, strength and plasticcharacteristics on the reinforcing phase content is shown to take place.
Key words: centrifuge, aluminum,nanoparticle, strength, metallocomposite, work hardening.
POROUS MATERIALS AND BIOMATERIALS
Ziganshin I.R., Porozova S.E.
Materials with micro- and nanoporosity based on zirconium dioxidewith different content of stabilizing additive
The effect of a stabilizing agent content on the phase compositionand pore space formation in ZrO2 based materials produced bygel-casting has been investigated. Raman spectroscopy has shown that porousmaterials with content of monoclinic phase over 50 % can be produced on thebasis of partly stabilized zirconium dioxide. Stabilization of ZrO2 byyttrium oxide in quantity of 8 and 15 wt. % results in precipitationof tetragonal and cubic phases accordingly. All produced materials have abimodal pore distribution in sizes. Increase of Y2O3content in the powder results in reduction of pore size and their amount.Sintering temperature is shown not to affect the porosity of samples, thustheir phase makeup also remains unchanged.
Key words: gel-casting, zirconiumdioxide, porosity, phase makeup, phase composition, yttrium oxide.
POROUS MATERIALS AND BIOMATERIALS
Maznoi A.S., Kidryashkin A.I., Maksimov Yu.M.
Techniques of stereometric analysis of porous penetrable materialmorphology
Stereometric techniques have been developed for estimation of themorphology of materials with complex structure of porosity. They allow us todetermine the quantitative characteristics of structure in three-dimensionalinterpretation, such as porous channel size, open porosity surface area,network element size of the porous structure. All the techniques are adaptedfor the possibility of computer data processing of the examined materialproduced by means of the computer picture scanner. The Saltykov method fordetermination of the number of closed pores and their size (diameter)distribution parameters in the geometrical number in the material volume ismodernized thus allowing us to expand the number of studied dimensional groupsand vary the value of denominator in the geometrical series of diameters. Themethodical features of structural anisotropy parameter calculation are shown.
Key words: porous penetrable materials,stereometric metallography.
POROUS MATERIALS AND BIOMATERIALS
Kirsanov Yu.A., Marfin E.A., Danilov V.A., Bashkirtsev G.V.
Simulation of geometrical and thermal properties of low-porousstructure
Geometrical models of low-porous structures with cubic, hexagonal,and tetrahedral packing of grains have been constructed. Formulas for volumeporosity, clearance, specific surface, and equivalent diameters of frameworkchannels and crosspieces for each packing have been derived. The equations forrelative thermal parameters of the framework - thermal and temperatureconductivity are proposed. The comparative analysis of the obtained resultswith literary data has shown their satisfactory coincidence.
Key words: porous structure, model,geometry, framework, porosity, clearance, specific surface, equivalentdiameter, thermal conductivity, temperature conductivity.
SURFACE MODIFYING, USING CHARGE-PARTICLE BEAMS, PHOTON AND PLASMAFLUXES
Rakoch A.G., Bardin I.V., Kovalev V.L., Avanesyan T.G., SeferyanA.G.
Microarc oxidation of light structural alloys. Part 2. The effect ofcurrent shape on microarc coating growth kinetics in alkaline (pH ≤ 12.5)electrolytes
Based on the experimental data the mechanism of the effect ofcathode alternating-current component on the growth kinetics and limitingthickness of microarc coatings being formed on the surfaces of aluminum andmagnesium alloys is proposed. When microarc oxidation takes place, the cathodealternating-current component increases (in case of Al-alloy) or decreases(Mg-alloy) the amount of effective microarc discharges because of increasingelectrolyte pH in through pores of the coating and temperature rise inproceeding the microarc oxidation process.
Key words: microarc oxidation, currentshape, coating thickness and growth rate, cathode alternating-currentcomponent, microarc coatings.
SURFACE MODIFYING, USING CHARGE-PARTICLE BEAMS, PHOTON AND PLASMAFLUXES
Uglov V.V., Remnyov G.E., Kuleshov A.K., Astashinsky V.M.,Saltymakov M.S.
Modification of T15K6 hard alloy metal by high-power pulse ion beamsand compression plasma flows
The change of morphology, phase composition, surface layer hardness,microstructure, and elemental composition of inner layers of hard alloy havebeen investigated after their exposure by high-power pulse ion beams (HIPIB)and compression plasma flows (CPF). The thickness of melt surface layerincreases up to 3–4 after 300 pulses with duration of 9·10–2 msec ofsummary energy density of 430 J/cm2. The CPF processing features areprolonged processing time of CPF pulse (100 msec) and predominantly convectivemixing of the melt layer. As a result, thicker (10 mm) layer of (W,Ti)C solid solution with uniform element depth distribution and high hardness (30GPa) is formed.
Key words: solid alloy, pulse ion beam,pulse plasma, X-ray diffraction, hardness.
CHRONICLE
Azizbekyan V.G., Kozhin A.M., Koftelev V.T., Rusyaev A.A., Korzhankova G.A., Shishkina I.P., Gushchevarov M.V., Naumov V.V.
Technical policy of OAO "Avtovaz" and OOO"Dmitrovgrad plant of powder metallurgy" in the field of metalpowders
The primary elements of work - "rules" - in the field ofthe metal powders developed in the course of more than 40-year joint work byexperts of powder metallurgy shop, department of laboratory-test works at OAO"AUTOVAZ" and OOO "Dimitrovgrad plant of powder metallurgy"are stated. The described experience can be useful to other enterprises workingin the field of powder metallurgy.
Key words: powders, powder metallurgy,iron, properties, explorations, techniques, productions, rules.
