ELASTIC MODULUS DETERMINATION OF NANOLAYERS BY THE ATOMIC-FORCE MICROSCOPY METHOD

Pogotskaya I.V., Engineer of the Institute of Heat and Mass Transfer n.a. A.V. Lykov of the NAS of Belarus, Minsk, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.

Kuznetsova T.A., Senior Researcher of the Institute of Heat and Mass Transfer n.a. A.V. Lykov of the NAS of Belarus, Minsk, Republic of Belarus

Chizhik S.A., Corresponding member of the NAS of Belarus, Doctor of Technical Sciences, Professor, Chief Scientific Secretary of the NAS of Belarus, Minsk, Republic of Belarus

We defined the local elastic modulus of single layer, polyvinylpyridine (PVP), and twolayer, polymethylmethacrylate coated with a polyvinylpyridine (PMMA+PVP). Polymer films with nanometer thickness (10-13 nm) formed on the silicon surface using the LangmuirBlodgett method. The experiment was conducted using the static force spectroscopy mode of atomic force microscopy method provides data about the bending of the console of the probe during its contact with the surface of the sample. Estimates were based on a mathematical model of contact deformation of layered systems, taking into account the thickness of the coating and the effect of the substrate. Based on the data of the elastic properties of thin coatings has been suggested the influence of the hyperfine polymer layer of PMMA to the properties of twolayer coating as a result of its force fields of silicon screening, which have a structuring effect on the inflicted layer.

atomic force microscopy, Langmuir-Blodgett films, elastic modulus

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ABOUT THE PROCESS OF METAL MICROFRACTURE AT COMPLEX STRESS STATE

Zavoichinskaya Je.B., Associate Professor of the Department "Theory of Elasticity", Mechanics and Mathematics Faculty, Moscow State University, Moscow, Russia, This email address is being protected from spambots. You need JavaScript enabled to view it.

Here is presented the mathematical model described the volume microfracture of metals considering sequences of origin and grow of submicroscopic, microscopic and short cracks at complex stress state. The notions of the crack total length and the microfracture probability at the total length equal to its characteristic values are the main notions of the model. The model is based on experimental mechanical parameters of material strength and fracture. Relations for determination of origin cycles for microcracks and short cracks as a result of consecutive origin and grow of submicrocracks, submicrocracks and microcracks correspondingly are obtained.

symmetrical harmonic loading, processes of micro and macro metal destruction, submicro cracks, microcracks, short crack, brittle fracture

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CONTROL OF THERMAL CONDITIONS ON GRINDING OF SHAFTS BY DISK BRUSHES

Ustinovich D.F., Candidate of technical Sciences, Scientific Secretary of the Physico-Technical Institute of NAS of Belarus, Minsk, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.

Golub V.M., Researcher, Physico-Technical Institute of NAS of Belarus, Minsk, Republic of Belarus

The investigation has been made of the calculated values of contact temperature magnitudes, depth of thermal effect and the temperature conditions required for processing of shafts made of the 45, 12X18H10T and 40X13 constructional steels have been evaluated. It is established that the kinematic process parameters (cutting speed and frequency of a part rotation) and thermophysical characteristics of a part affect the value of a contact temperature in a processing zone as well as the nature of temperature of subsurface region. The increase in a cutting speed and decrease in frequency of a part rotation are shown to contribute to enhancing the power of a thermal source and values of a contact temperature. It is found that in order to ensure stable process of cutting and operating characteristics of a tool its cutting speed should not exceed 18 to 20 m/s when processing parts of a shaft type without cooling.

grinding, contact temperature, disk brush, structural steel, heat mode, processing modes

• Ustinovich D.F., Pribyl'skij V.I. Otdelochno-zachistnaja obrabotka listovyh materialov jelastichnym instrumentom s diskretnym rezhushhim konturom [Finishing-stripping treatment of flexible sheet material cutting tool with a discrete circuit]. Mashinostroenie i tehnosfera XXI veka: sb. tr. XVI Mezhdunar. nauch.-tehn. konf. [Mechanical engineering and technosphere of the XXI century: Coll. of sci. papers XVI Intern. scientific and engineering. conf.]. Doneck, DonNTU, 2009, vol. 3, pp. 176-179.
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FUNCTIONAL DEPENDENCES FOR INTERNAL FRICTION FORCES IN PREPREGS DURING DEFORMATION

Vasilevich Yu.V., Doctor of Physical and Mathematical Sciences, Professor, Head of the Department "Resistance of Materials of Engineering Profile", Belarusian National Technical University, Minsk, Republic of Belarus, This email address is being protected from spambots. You need JavaScript enabled to view it.

Sakhonenko V.M., Candidate of Physical and Mathematical Sciences, Professor, Head of the Department "Applied Mathematics", Moscow State Open University, Moscow, Russia

Sakhonenko S.V., Candidate of Physical and Mathematical Sciences, Acting Associate Professor of the Department "Resistance of Materials of Engineering Profile", Belarusian National Technical University, Minsk, Republic of Belarus

Gorely K.A., General Director of the JSC "Avanguard", Minsk, Republic of Belarus

Malyutin E.V., Chief Designer of the JSC "Avanguard", Minsk, Republic of Belarus

For prepregs, which are orthotropic multilayered structure on the basis of glass smooth weaving fabrics, having an ordered arrangement of yarn layers and impregnated with a resin in the uncured state of polymers at plane stress state, were found the expressions for the components of the limit friction force applied to the thread families in the nodes of interweaving. They are represented by linear relations between stress in threads and compression between the textile layers.

prepreg, fiber, cloth, internal friction, deformation

• Jejdelman L.Ja. Igla dlja prokalyvanija otverstija [Needle for pierce holes]. Author’s certificate, no. 78397, 1950.
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