Science Intensive Technologies in Mechanical Engineering          

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Science intensive technologies in mechanical engineering, 5, 2017

Kh.M. Rakhimyanov, A. Kh. Rakhimyanov
Influence of material melt kinematic viscosity upon treatment quality at fine-jet plasma cutting of bimetallic compositions
The paper reports the peculiarities in the formation of a cut slot of bimetallic steel 3 + aluminum 5 M composition and steel 3 + copper M1 composition at fine-jet plasma cutting. A different character of a cut channel formation of compositions at a package cut on different sides is revealed. When processing steel + aluminum composition on the side of steel a cut surface on the aluminum area has course roughness. A burr formation on the lower edge of a cut is also observed. It is explained by considerable difference in melting temperatures and thermal conduction of steel and aluminum. At the changed of a front side of a cut from steel to aluminum occurs sedimentation of aluminum melt on the steel area which is explained by a high kinematic viscosity of aluminum melt. The formation of refractory oxides in aluminum melt is defined that contributes to the increase of its viscosity and difficulty in the complete elimination from a cut channel. At the cutting of bimetallic steel 3 + copper M1 composition of a copper side a cut surface on both areas is formed without visible traces of sedimentation of steel and copper melt caused by a low kinematic viscosity of copper and steel melts.
Keywords: fine-jet plasma cutting; bimetallic compositions; cut accuracy and quality; melt kinematic viscosity

S.M. Bratan, V.B. Bogutsky, Yu.K. Novosyolov, S.I. Roshchupkin
Process simulation of tool and blank stochastic interaction in grinding operations
The interaction analysis of abrasive grain tip contact probability with the material, number, the form and length of single cuts at finishing processes of flat grinding is presented. It is shown that when passing a contact area of a blank with a disk a grain can cut material off, if it falls on one of protrusions of surface roughness, or will not cut it, if it falls on one of roughness cavities. The dependencies obtained in the work allow estimating the influence of a grinding mode and tool characteristics on the length of single cuts, defining basic parameters of a grinding process, watching regularities in the formation of micro-relief formation on the surface worked and forming its rated profile which can be obtained at the operation fulfillment. The example of the computation and formation of a theoretical profile of a surface micro-relief is shown
Keywords: grinding; abrasive grain; tool and blank interaction; material removal probability; grinding process parameters

I.A. Gorobets, A.N. Michailov, N.V. Golubov
Quality increase in stone blank grinding
The problems of planning and experiment setting, measuring equipment, tools and equipment used are described. There are shown results of experimental investigations of granite grinding process. A simulator for the assessment of the topography of a surface worked in a blank is developed. A method of technological impact at processing a blank by grinding and a design of an adaptive device are offered. The 3D model of an adaptive device for the flat grinding of a surface in a stone blank is developed. The description of the device components and its operation principles are shown
Keywords: quality; stone; experiment; investigation; topography; structure

A.F. Denisenko
Dynamic characteristics of mean type dimension lathe installed on rubber-metal anti-vibration supports
On the basis of a nonlinear dynamic model of a vibration-proof system at power excitation there are formed amplitude-frequency characteristics of a lathe installed on rubber-metal anti-vibration supports, and an area of efficient vibration isolation is defined. An elastic characteristic of the model is presented as an approximating dependence obtained on the basis of the experimental dependence of support elastic deformation changes upon loading
Keywords: vibration isolation; rubber-metal support; elastic characteristic; approximating dependence; amplitude-frequency characteristic; effective vibration isolation area

V.F. Makarov, S.P. Nikitin, M.V. Pesin, A.S. Gorbunov
Impact of local technological concentrators of stresses upon operation properties of parts work
It is defined that during the machining of complex surfaces in parts operating under large fluctuating loads, in critical transition areas of profile conjugate surfaces there are formed local technological concentrators of stresses contributing to formation, development of fatigue cracks and to further destruction of parts in the course of operation. Such phenomena are discovered, for instance, at high-loaded gear teeth machining, at turbine blade profile surface machining, at manufacturing large-modular tapered threads and other parts having complex profile surfaces. There are developed and introduced methods for value decrease of such stress concentrators on the basis of the application of different methods for local surface plastic deformation of a surface layer in transition areas of profiles. As a result the probability of fatigue crack formation decreased considerably and fatigue strength in parts machined increased essentially
Keywords: stress technological concentrators; profile surface; local transition areas; fatigue strength; thread; gears; turbine blades

S.A. Zaydes, Pham Dac Phuong
Assessment of stress-strain state in cylindrical parts after transverse running with flat plates
For the deformation strengthening of parts like axles, pins, and bushes there is offered a method of surface plastic deformation based on blank rolling with flat plates. The method allows machining parts which do not have center holes. At transverse running a blank bending affected by transverse loading forces is excluded. With the aid of ANSYS program complex there is considered a change of a stress-strain state in cylindrical parts at transverse running. There are defined plastic and elastic cylinder deformations after loading. The distribution of residual stresses along cylinder section in the plane of vertical loading is obtained. The stress state of samples run with flat plates on equivalent stress is assessed. An efficient value of running at transverse running used as a basic parameter of surface plastic deformation is defined
Keywords: strengthening; transverse running; relative squeezing; stress-strain state; elastic-plastic deformation; cylinder

M.A. Yakimova, V.I. Alekhnovich, A.G. Grigoriyants
NPVO Refractometer for diffusing substance investigations
The paper deals with the use of refractometry for the analysis of strongly scattering materials. The peculiarities in the interpretation of measurement results, and in particular, the simulation of attenuation factors of a flat and damped wave for the use in the equation of coupling are considered. Besides, there is investigated a degree of the influence of different parameters (concentration of particles and their parameters) upon results of experiments which will improve accuracy and reliability of experiments. The results of experiments are obtained with the aid of NPVO refractometer on strongly scattering samples with a calibrated composition. The processing of experiment results carried out with the use of Mi scattering factors and scattering factors of standing wave allows estimating in what cases it makes sense to use more complex expressions for a damped wave and in what cases may be used Mi factors
Keywords: refractometer; attenuation factor; damped wave; coupling equation

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