Keresés
Keresési eredmények
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Micromechanical Model of Dry Friction Hybrid Polymer Composite Clutch Facings
335-340Megtekintések száma:100Modelling the complex coupled thermomechanical and tribological contact of a dry friction clutch system between cast iron flywheel and scatter-wound hybrid composite clutch facing requires a thought through investigation of the friction material properties and behaviour. Challenges of the creation of a mechanical stiffness matrix for such a complex material are described in this paper along with simplification ideas and solutions.
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Analysis of Vibration During Turning Process of Different Materials
200-205Megtekintések száma:132In this article, we would like to introduce the problems caused by vibrations in case of polymer turning processes. Nowadays there is a lot of research in this topic, to avoid the unnecessary phenomena of vibrations. The two most common methods are the Spindle Speed Variation (SSV), and the Vibration Assisted Machining (VAM). In case of SSV, the CNC machine can increase and decrease the speed of spindle continuously during turning which can significantly reduce the effects of chatter. This method is beneficial for longer workpieces when there is not any support except the chuck. Vibration-assisted machining can be used to minimise the problems caused by vibrations. VAM combines precision machining with small-amplitude tool vibration to improve the fabrication process. It has been applied to some processes ranging from turning, drilling to grinding. Based on the enumerated above we made some trial measurements about the basic vibrations of the turning tool shank. The tests were done on an NCT EUROturn-12B CNC machine which can found in the workshop of our institute. The tested material was Polyamide 6 because this is the most commonly used polymer in the industry. In the future, we would like to test some other basic and composite polymer materials too. The equipment was served by a specialist from SPM Budapest Kft. With these tests, our goal was to make sure that the equipment and the measuring setup are suitable for our future research.
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New Method for Dynamic Tribological Test of Engineering Polymers
25-29Megtekintések száma:134In this article, tribological tests of Polyamide 6 (PA 6), Ultra High Molecular Weight Polyethylene (UHMW PE) and Polyoxymethylene copolymer (POM C) by a new testing method is introduced. The tribometer used in the test is capable for pin-on-disc measuring within all possible layout known in tribology practice, otherwise can be modified into special model of fatigue sliding test. The pin was a specimen made from examined materials, always in contact with a rotating metal disc under a normal load, which is usually static. However, since vibration exists in every practical scene as an important phenomenon, for instance in turning process, we added vibration load into the test. The supplement load is generated by a special-designed vibrating machine. Then properties of examined materials can be studied more profoundly under vibration load. As a result, different value of friction coefficient in static and vibration load have been discovered and taken into comparison.
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Pin on disc vizsgálatok zártcellás alumíniumhabokon
353-357Megtekintések száma:219A fémhabok cellás szerkezetük és kiváló mechanikai és fizikai tulajdonságaik révén előtérben vannak a jármű és egyéb iparágak anyagfejlesztéseiben. Ugyan a különböző típusú fémhabok közkedveltek, a bonyolult szerkezetük miatt továbbra is kutatások tárgyai. Jelen kutatás célja különböző gyártástechnológiával készült és különböző cellaméretű zártcellás fémhabok tribológiai vizsgálata. A cikkben bemutatásra kerülnek a vizsgálat tárgyai, azaz a direkt habosítással és gázinjektálással készült zártcellás alumíniumhabok és azok mátrixanyagai. Részletezésre kerül továbbá a kísérletekhez használt Pin on Disc vizsgálóberendezés, valamint a kísérletek legfontosabb paraméterei.
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A Slurry-Pot Abrasive Wear Test Device for Several Composite Materials
437-444Megtekintések száma:107To choose the proper material for agricultural machinery we tested several materials with abrasive cloth on the pin-on-plate test device. After having the pre-results, we launched more complex abrasive testing (slurry-pot) simulating more realistic mode with soils to investigate the abrasive wear mechanism and resistance of the selected up-to-date polymeric structural materials. for this, we developed a modified slurry-pot test machine that ensures the comparability of the materials over a wide range of conditions. Through this device, several parameters could be controlled like speed, the soil particle’s hit angle on the tested surface.
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The Effect of Sizes of the Cast Polyamide 6 Rods upon Tensile-Impact Strength
21-24Megtekintések száma:144We have studied the tensile-impact strength of the magnesium catalysed cast polyamide 6 (PA6) rods according to the EN ISO 8256:2004 standard. The purpose of our investigation was to follow: the mechanical properties of rods are mapped beside same casting technological process in case of different diameters. We have compared the received results with each other than have sought disparities. We examined cylindrical product (rod) in seven dimensional steps in diameter ranging from 40 mm to 300 mm. We have determined that the semi-finished products can be divided into two groups typically in case of their tensile-impact strengths in this size range. The tensile-impact strength is higher in case of the rods with a diameter of less than 100 mm and it is smaller in the larger dimension range. Therefore, the smallest tensile-impact strength can be established in case of the natural semifinished PA6 rods that each rod accomplishes independently of size. However, a range can be determined, which the tensile-impact strength values of product are separated according to the manufacturing size
