Papers by Keyword: Abrasive

Abstract: The article is devoted to the problems of fractioning the general abrasive mass into the fractions of certain shape grains. The methods of separation of bulk materials have been analyzed. The designs are considered and the operating principle of the original units for abrasive separation is described. The revealed regularities at the separation of abrasive masses of various granularities are presented.

Abstract: It is proved that abrasive-holding conglomerates are effectively destroyed when slime is separated in the non-uniform electromagnetic field, which results in steel chips and abrasive separation. Magnetic wave separation technology mechanism for bearing production grinding slime is described in the article. The techniques for optimal regimes of magnetic field gradient determination and alternating magnetic field induction intervals regulation for the effective separation of magnetic and non-magnetic fractions are proposed. Practical application options for the slime separation products are shown.

Abstract: Recent years have highly been productive in terms of development of both conventional machining technology, but in workpiece surfaces finishing, as well. The overall trend is heading towards increasing accuracy and quality of the manufactured components for machinery and equipment. In a range of finishing abrasive technologies there has been known the introduction of microcrystalline corundum, modification of tools with these abrasive grains, including sintered tools. This development continues and the latest trend is the development of pyramidal grain the Cubitron II. How individual grains behave during operation and how we can use their properties in comparison to classic white corundum still remains complicated matter. The behaviour of selected abrasives has been described in the submitted article.

Abstract: Productivity of internal grinding processes is limited by wheel-workpiece contact area and high temperature generated during grinding. Existing internal grinding methods do not guarantee presence of coolant liquid in the heat generation zone. Usually coolant liquid from external nozzles could not penetrate turbulent air flow around grinding wheel. Assembled wheel with radially mobile segments allows increasing contact area but needs to be supported by more efficient heat evacuation system. New grinding wheel and method of internal grinding are developed and evaluated. New tool generates high speed hydrodynamic circular flow and dynamic wedges of coolant liquid in the cutting zones.

Abstract: The article presents the results of Technical University in Košice Faculty of Manufacturing Technologies Department of production processes operation and Technical University in Ostrava Physics Institute Liquid jet workplace cooperation in the area of operational states diagnosis of manufacturing systems with abrasive water jet technology (AWJ). Within the operational states diagnostics is the impact of selected technological parameters on technological head vibrations studied. Based on an extensive set of experiments are original graphical dependences determined of the abrasive mass flow and feed speed impact on the vibrations parameter - technological head vibrations acceleration amplitude of manufacturing system with AWJ technology. In addition to the original graphical dependences are in article new knowledge formulated in the area of science and research and recommendations for companies that operates manufacturing systems with AWJ technology.

Abstract: At the present time the problem of import substitution of grinding tools is particularly of current interest. The current situation makes many foreign producers gradually leave the Russian market while domestic enterprises cannot offer competitive grinding tools that possess the characteristics and quality comparable to foreign analogs.

Abstract: This study investigated the removal improvement of micro burrs of aluminum alloy materials using vibrated abrasive grinding machining. The image processing technology is used to examine and quantify the micro-hole burr profiles. The experimental results show that the micro burr was uniformly removed as the workpiece is fixture with vertical direction. In addition, the burr removal improvements are effectively influenced by the flowing velocity and the vibration energy of abrasive particles. The flowing velocities are dependent on the size and gravity of the abrasives and the vibration energy is determined by the material properties and the hardness of the abrasives.

Abstract: The paper presents and analyzes the experimental research results of impact in abrasive mass flow changes and sieving on technological head vibrations while cutting steel HARDOX 500 using the water jet technology. Vibrations were quantified by two basic parameters (vibrations frequency and vibrations acceleration amplitude). The experiments evaluation contains graphical dependence sets of vibrations acceleration amplitude on frequency, set of frequency spectrum envelopes and comparative graphs of frequency spectrum envelopes based on which new knowledge and recommendations have been created.

Abstract: Numerical investigations of the abrasive influence on material removal efficiency of the micro-hole for AFM process is conducted in this paper. A three-dimensional model is constructed for this process. The abrasive with various particles volume fraction and different micro-holes with various diameters are selected in this study. The simulation results show that the lower particle volume fraction may be in favour of the metal removal uniformity, but the processing time will be too long if too low fraction is selected.

Abstract: Finishing process (Grinding and Polishing), is still manually performed, specially in free form surface parts. This involves a series of remaining problems, mainly related with the geometrical shape of the finished part. In traditional manually finishing task, the final quality aspect of the part is the only parameter to be controlled. This supposes a lack in the quality parameter control, mainly in high level parts, as in automotive, aeronautics or mould making parts. Manual finishing has not any control about the amount of material removed, during finishing process, affecting this way to the final geometrical shape of the product. This is the reason why this investigation proposes an exhaustive research of the parameter influencing the finishing tasks, and defining a finishing methodology adapted for an automatic process executed by a spherical robot. Making it an automatic way, and controlling paths, tool, abrasive, and defining a mathematical model for the finishing process, final quality of the part and product will be optimized, from a quality point of view, at the same time process time and cost is reduced.