THE СHOICE OF PRECIPITATION PARAMETERS OF VACUUM-ARC NANOCRYSTALLINE COATING FOR INCREASING WEAR RESISTANCE OF PISTON RINGS
| Autor: | Hlushkova, D. B., Kostina, L. L., Stepaniuk, A. I. |
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| Jazyk: | ukrajinština |
| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Вісник Харківського національного автомобільно-дорожнього університету; № 82 (2018); 56 Bulletin of Kharkov National Automobile and Highway University; № 82 (2018); 56 Вестник Харьковского национального автомобильно-дорожного университета; № 82 (2018); 56 |
| ISSN: | 2219-5548 |
| Popis: | Основной причиной выхода из строя поршневых колец является изнашивание рабочих поверхностей. В работе проведено исследование многослойного нанострук¬турного покрытия, нанесенного на поверхность поршневых колец для повышения их износостойкости. Покрытие наносили вакуумно-дуговым методом на серый чугун. Установлено, что в поверхностном слое создаются сжимающие напряжения, а твердость в приповерхностном слое повышается, что приводит к значительному повышению износостойкости. Головною причиною руйнування поршневих кілець є зношування робочої поверхні. В роботі проведено дослідження багатошарового нанострук¬турного покриття, нанесеного на поверхню поршневих кілець, для підвищення їх зносостійкості. Покриття наносили вакуумно-дуговим методом на сірий чавун. Встановлено, что в поверхневому шарі утворюються стискаючі напруження, а твердість в приповерхневому шарі підвищується, що приводить до значного підвищення зносостійкості. The production of piston rings the main failure of which is wearing of working surfaces takes a considerable place during various parts producing. The wear resistance of metal is determined by combination of a structure, high hardness and plasticity, stability of mechanical properties, the high saturation and the uniform distribution of alloying elements. It has been investigated the influence of multi-layered vacuum-arc nanostructure coating on wear resistance of piston rings. The material on the multi-layered coating was applied by means of vacuum-arc method was the grey cast-iron. Multi-layered two-phase nanostructural coatings TiN-MoN were precipitated in the vacuum-arc plant "Bulat-6". Nanoindentation was conducted by means of a pyramid of Berkovich at loading 0,5 H with loading and unloading executed automatically. Metallography researches were conducted by means of electronic microscope, study of the structural state of coverages was performed on a scanning microscope. The quantity of residual stresses in near-surface layers was determined on the difraktometr rentgenovskiy DRON-2 by means of procedure of multiplied inclined shootings in radiation of copper anode with graphite monochromator. The tests for wear resistance were performed on the plant SMTs-2.Research of the structural state of coatings showed that at the layer thickness about 2 nм there is no interface border and that’s why a spectrum is revealed on diffractive spectrums that is typical for monophasic state and material is hardened not much. The absence of detectability of the interphase boundary indicates the epitaxial growth of thin layers. The hardness increases at occurrence of the second phase.In case of studying the layers of thickness about 10 nm it is observed the forming of two-phase structural state. The interfaces occupy a large specific volume, that is accompanied by the increasing of compressive stresses. It must result in hardening.Coatings over 20nm thick are also biphase and very hard. Increasing the compressive stresses and increasing the hardness in the near-surface layer leads to a significant increase in wear resistance. Linear wear of cast-iron sprayed with coating Ti-Mo-N decreases in 8 times. |
| Databáze: | OpenAIRE |
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