FRACTURE FEATURES OF METAL BINDING WHEN DIAMOND-SPARK GRINDING

The hypothesis of the influence of binding energy of metal on the processes of destruction and mass transfer at high-speed machining is considered. Some nonconventional processes of cleaning of intergranularity spaces from waste products at diamond-spark grinding are explained, the approach to assessment of metal resistance in these processes is proposed and eo ipso modern conception of processes in chip formation zone under condition of electric discharge effect is supplemente

ACTIVATED HOT PRESSING BEHAVIOR OF WC NANOPOWDERS

The questions of consolidation of nanopowders concerning hot compaction by pressing activated by electric current action are considered. Mechanisms of grain boundary creep-sliding which are sequentially prevalent in a forming of compacted structures under influence of temperature factor and in the presence of a direct electric heating are discussed. Structural-transformational sources and conditions of forming of high physical-mechanical properties of nanopowder refractory solid-state products are described

MODELING OF RUNNING CUTTERS FOR SHAPING OF IMPROVED NONINVOLUTE TOOTH GEARS

The questions of tooling design for production of advanced gears are considered. Engineering is based on the special applied development of the mathematical theory of multiparametric mappings of space. In fulfilled engineering of gear cutting tools for shaping of noninvolute gears it is provided for exclusion of distorted profiling after tool regrinds. There are proposed calculation algorithms, which may be used in dataware of respective CAD/CAM systems of maintenance for tooling backup. Among developed tools there are assembled shaping cutters with prismatic and round cutters. Compensatory possibilities of proposed assembled shaping cutters are ensured by repositioning of shaped cutting edges after their regrindings: by linear displacement of prismatic shaped cutters and angular displacement of round ones respectively

Exploitative destruction features for detonation ultra-dispersed diamonds of initial metallic protection for abrasive powder grains to diamond-spark grinding tools

The problem of exploitation of diamond grinding wheels with metal coating for their grains including detonation ultra-dispersed diamonds to increase functional reliability to maintain the initial integrity of grains in the pressing and sintering of diamond-metal composites in the tool production is considered. One problem is that the presence of detonation ultra-dispersed diamonds in the grain metal coating of diamond powders not only improves the coating functional reliability in protection from destruction in the subsequent pressing and sintering in the production tool, but also resistance of such coating to the opening of the diamond cutting basis of the grains on the grinding wheel working surface that come into working contact with the material being processed. An analysis of the features of an effective exploitative destruction of detonation ultra-dispersed diamonds in the metal coating using electric current in the tool of the diamond-spark grinding processes is presented

Analysis and comparative description of preparation methods of small cylindrical connections precision surfaces to the assembly

The article describes the methods of finishing precision surfaces of small cylindrical connections

Analysis and comparative description of preparation methods of small cylindrical connections precision surfaces to the assembly

The article describes the methods of finishing precision surfaces of small cylindrical connections

SYNTHESIS OF MODEL THE LUENBERGER OBSERVER FOR EXTERNAL CYLINDRICAL GRINDING PROCESS

The problem of diagnosing the actual depth of cut at cylindrical grinding is considered.A mathematical model of the behavior of the grinding wheel and the workpiece during processingis worked out. According to this model it is produced a synthesis the model of the Luenbergerobserver with the Kalman filter to control the process of external cylindrical grinding. Thedeveloped approach is to improve the accuracy of control and the related with them computationalprocedures of assessment and managemen

ANALYTICAL DETERMINATION OF CONDITIONS FOR PRODUCTIVITY IMPROVEMENT OF DIAMOND GRINDING

The analytical dependences for definition of processing productivity when grinding by diamond wheels on metal bonds with the accounting of linear wear of the grain which is the most acting over the level of bond are given on the basis of probability-theoretic approach.. Conditions of electroerosive dressing with providing the optimum cutting relief of diamond wheel are defined. A high-performance process of longitudinal external cylindrical diamond grinding of fast-cutting and hard-alloy multiedge tools (mills, reamers, core drills, etc.) is developed with high quality of processing and renting allowance to 1,2 mm per side in one pass

CONDITIONS FOR ENERGY CAPACITY REDUCING OF TREATMENT AT DIAMOND GRINDING

The main parameters of diamond grinding were determined analytically, taking into account the formation of steady cutting relief on the working surface of a wheel. This made it possible to substantiate the conditions for reducing the energy intensity of processing (conditional cutting stress), which consist in the use of both multi-pass grinding and high-performance depth grinding at a relatively low workpiece speed. It is shown that grinding with diamond wheels on metal bonds leads to an increase in the intensity of processing. Therefore, it can be reduced by increasing the grain size of the wheel, as well as by applying continuous electroerosive dressing or diamond spark grinding, which allow for the bulk destruction of grains and their timely removal from the working surface of the wheel, which maximizes the use of significant technological capabilities of diamond wheels on metal bonds with a significant increase productivity and quality of processing.

SOME GENERALIZATIONS AND REPRESENTATIONS OF THE POSSIBILITIES OF MULTI-PARAMETRIC MAPPING OF AFFIN SPACE IN AN APPENDIX TO THE CURVOLINEAR FORMING AND TRANSMISSION MOVEMENT

The works of Prof. B. A. Perepelitsa from Kharkov Polytechnic Institute and his disciples to develop an applied methodology of multiparameter mappings in relation to the profiling and functioning of complex curvilinear objects and transmission mechanisms in mechanical engineering, mainly with examples of gears, are presented. The completed review is gratefully devoted to the 10th anniversary of Fiability & Durability Journal, which has repeatedly provided its platform to the authors to highlight this development of the wide Romanian, European and world scientific community