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1

Overview of investigations focused on lubricants efficiency improvement with metal nanoparticles addition

Kotnarowski A.

Logistyka

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2015

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nr 3

2336--2345, CD 1

EN

Nanoparticles of some metals, thanks to extraordinary properties possessed by nanostructures and connected with quantum and superficial aspects of their nature, are proposed as antifriction and antiwear lubricants additives. The results of investigations made about possibilities of copper or molybdenum nanoparticles use as additives to base oils applied to, among others, lubricating, cutting, and other lubricating oils compounding, are presented. These nanoparticles added to oils modify their tribological properties observed during presented investigations in model sliding couples of friction testing equipment.. Such field of investigations results from some few reports about positive influence of metal nanoparticles as additives to lubricating oils and mainly from the examination made by the author in this research area. Examination results presented in the paper prove positive influence of copper and molybdenum nanoparticles on tribological properties of lubricants consisting in friction resistance and wear decrease in couples lubricated with these lubricants.

PL

Z powodu niezwykłych własności nanostruktur, związanych z kwantowym i powierzchniowym aspektem ich natury, proponuje się zastosowanie nanocząstek metali jako dodatków przeciwtarciowych i przeciwzużyciowych do środków smarowych. Zaprezentowano wyniki badań możliwości stosowania nanocząstek miedzi lub molibdenu jako dodatków do olejów bazowych, stosownych między innymi do komponowania olejów obróbkowych i innych olejów smarowych. Nanocząstki dodane do oleju modyfikują jego właściwości tribologiczne, obserwowane w trakcie omawianych badań w modelowych skojarzeniach ślizgowych badawczych urządzeń tarciowych. Prezentowany zakres badań wynika z nielicznych doniesień na temat korzystnego działania nanocząstek metali, jako dodatków do olejów smarowych, a przede wszystkim, z wykonanych przez autora badań w tym zakresie. Wyniki prezentowane w artykule potwierdzają pozytywny wpływ nanocząstek miedzi i molibdenu na właściwości tribologiczne środków smarowych, polegający na zmniejszeniu oporów tarcia oraz zużycia skojarzeń nimi smarowanych.

2

Effects of the friction reducer on the standard PENCEL pressuremeter cone tip in soft clays

Messaoud F., Houam A.

Studia Geotechnica et Mechanica

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2010

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Vol. 32, nr 3

55-69

EN

This study was performed to evaluate a standard method of PENCEL pressuremeter (PPMT) testing to allow engineers to more precisely carry out the standardized tests and to generate the p-y curves for analysis and design of deep foundations. Based on the results of a comprehensive testing program the evaluation indicates that the testing procedure is acceptable. A recommended interpretation and procedure are presented. The effects of adding a 1/16-inch friction reducer to the standard PENCEL cone tip used for clay soils were negligible. Dilatometer tests (DMT) were conducted for comparison with PPMT data. From PPMT data, which were reduced to graphs of pressure versus volume and pressure versus relative change in probe radius, soil parameters including the initial pressure, the initial moduli, the reload moduli, and the limit pressure of the clay were determined. The PPMT soil parameters from both types of cone tip show a good agreement with published values. Correlations were found between the PPMT and DMT results, which show consistency in the values of soil parameters. A comparison between PPMT and DMT p-y curves was made. The initial slope of the curve shows a good agreement for this comparison. The predicted DMT and PPMT ultimate loads are not similar, while the predicted PPMT and DMT deflections within the elastic range are identical. The PPMT is a suitable in-situ tool to duplicate the pile installation and to predict the resistance of laterally loaded soil for the purpose of analysis.

3

Hard and superhard nanolaminate and nanocomposite coatings for machine elements based on Ti6Al4V alloy

Wendler B., Moskalewicz T., Progalskiy I., Pawlak W., Makówka M., Włodarczyk K., Nolbrzak P., Czyrska-Filemonowicz A., Rylski A.

Journal of Achievements in Materials and Manufacturing Engineering

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2010

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Vol. 43, nr 1

455--462

EN

Purpose: Verification of a series of hybrid treatments of Ti6Al4V alloy consisting of primary diffusion hardening of the substrate with subsequent deposition of wear resistant coatings. Design/methodology/approach: Different nanolaminate and nanocomposite coatings were deposited with use of four different methods including a newly developed high density gas pulsed plasma MS technique. After deposition the coatings were investigated using OM, SEM, HRTEM, XRD, XPS, nanoindentation, Daimler-Benz, ball-on-plate and scratch tests. Findings: Besides an important increase of Ti6Al4V alloy hardness much greater further increase of hardness was obtained due to coatings deposition up to 53 GPa in case of a nanolaminate coating and to 47 GPa in case of a nanocomposite nc-TiN/a-SiN coating. At the same time the volume wear coefficient decreases several orders of magnitude for all the coatings. Simultaneously the friction coefficient decreased to a great extent except for the nc-TiN/a-SiN coating. Research limitations/implications: High density gas pulsed plasma magnetron sputtering is an effective method for superhard coatings deposition, however the roughness of the deposited nc-TiN/a-SiN coating was greater than after conventional magnetron sputtering. This finding needs further experimental and theoretical investigation. Practical implications: Greater surface roughness and high resistance to wear of the coatings synthesized using the newly developed gas pulsed plasma magnetron sputtering deposition limits their application to wear protection of cutting tools rather than for friction reduction in tribological couples. Originality/value: Applicability of the broad spectrum of nanolaminate and nanocomposite coatings as well as different CVD and PVD techniques for an improvement of tribological properties of Ti6Al4V alloy was analyzed in the paper including a newly developed original high density gas pulsed plasma magnetron sputtering technique.

4

Reaction mechanisms of alcohols on aluminum surfaces

Wiltord F., Martin J., Le Mogne T., Jarnias F., Querry M., Vergne P.

Tribologia

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2006

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nr 6

7-20

EN

The general aim of this work concerns the study of the lubricant/surface interaction mechanisms, such as those occurring during aluminum cold rolling in the presence of fatty alcohols. To improve the understanding of alcohol tribochemical reactions on an aluminum surface, friction tests followed by SIMS analyses were conducted. Deuterated alcohols were used to investigate the formation of bonds between the aluminum surface and alcohol molecules. The combination of SIMS analysis and the use of deuterated molecules have enabled us to propose a reaction mechanism between alcohols and the initial oxidized aluminum surface. This mechanism later affects the tribological behavior of the interface. In agreement with previous observations, we showed that a low steric size increases the number of acting molecules on the oxidized surface and that the alkyl chain length is of importance to protect the surface and hence reduce friction. These two key points can be easily explained by the proposed reaction pathway.

PL

Celem niniejszej pracy było zbadanie mechanizmów oddziaływań układu środek smarowy/powierzchnia, które między innymi mają miejsce podczas walcowania na zimno aluminium w obecności alkoholi tłuszczowych. Produkty tribochemicznych reakcji alkoholi, zachodzące na powierzchni aluminium, badano za pomocą spektrometrii masowej jonów wtórnych (SIMS). Aby zbadać tworzenie się wiązań pomiędzy powierzchnią aluminiową a cząsteczkami alkoholu, zastosowano deuterowane alkohole. Połączenie techniki SIMS oraz deuterowanych cząsteczek pozwoliło zaproponować mechanizm reakcji alkoholi i utlenionej powierzchni aluminium. Mechanizm ten wyjaśnia wpływ alkoholi na tribologiczne zachowanie się warstw wierzchnich współpracujących elementów. Zgodnie z poczynionymi wcześniej obserwacjami wykazano, że mniejszy rozmiar przeszkody sterycznej zwiększa liczbę oddziałujących cząsteczek z utlenioną powierzchnią, a także, że długość łańcucha alkilowego pełni istotną rolę w ochronie powierzchni i tym samym redukcji tarcia. Te dwa kluczowe aspekty można łatwo wytłumaczyć za pomocą zaproponowanych procesów tribochemicznych.