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Evaluation of some thermophysical properties of sn500 lubrication oil blended with SIO2, AL2O3 and TIO2 nano-additives, using fuzzy logic

Sankar E., Duraivelu K.

Acta Mechanica et Automatica

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2024

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Vol. 18, no. 2

352--360

EN

Nano-additives are generally blended with the base lubricant oil, to enhance the lubricant characteristics such as wear, coefficient of friction (CoF), thermal conductivity, density, and flash and fire points of the lubricant. In this research, nano-additives of SiO2, Al2O3 and TiO2 are blended with the base SN500 oil with different proportions of mixture. When these three nanoparticles are used together in base oil, they enhance most of the desirable properties of a lubricant; 27 samples with three different levels of a mixture of nano-additives are identified using factorial design of experiments. The experimental outcomes for the selected three characteristics of interest of density, flash point and fire point are determined. Conducting experiments for ‘n’ number of samples with different proportions of mixture of nano-additives is a cumbersome, expensive and time-consuming process, in order to determine the optimum mix of nano-additives for the desirable level of characteristics of interest. In this research, attempt has been made to apply fuzzy logic to simulate a greater number of samples with different proportions of a mixture of three nano-additives with the respective outcomes of characteristics of three thermophysical properties. Out of the numerous samples simulated using fuzzy logic, the sample with the optimum mix of three nano-additives of SiO2, Al2O3 and TiO2 blended with the base oil is identified for the desirable level of characteristics of interest of density, flash point and fire point. The values of the identified sample are found to be at the desirable level of 0.9008 gm/ml, 231°C and 252°C, respectively.

2

Preparation and characterization of silicone rubber socket liners modified by nanoparticles additives

Ameer Z.J.A.

Archives of Materials Science and Engineering

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2023

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Vol. 119, nr 1

21--30

EN

Purpose: The upper part of the prosthesis is called a socket, which contacts the amputated part. While wearing the prosthesis, there are several problems that the patient may suffer from, such as shear force between the socket and amputated part, pressure on the bony prominences, sweating, and bacteria generation, all leading to skin problems and a bad smell. It makes the patient refuse to wear the prosthesis because it is uncomfortable. Therefore, the aim of this study was comfortable lining from silicone rubber which cross-links at room temperature, with properties corresponding to the needs of this application, such as stress distribution, moisture absorption, and antibacterial. Design/methodology/approach: In the current work, silicone rubber was selected with the addition of nano-fillers (ZnO, Mg(OH)2, and Chitosan). Mechanical and physical properties were studied (tensile strength, tear strength, hardness, water absorption, porosity, and antibacterial). Findings: Chitosan showed the highest effect on the mechanical properties of silicon, as it achieved the highest value of tensile strength of 2.2 MPa elongation of 572%, tear strength 13.9 kN/m, and shore A hardness of 33.3. While the highest value of the modulus, 0.636 MPa was achieved by adding ZnO. The results also showed an increase in the water absorption and the porosity, which were the highest values at 1.6 % and 0.24%, respectively with the addition of Mg(OH)2. The samples showed a clear resistance to preventing the microorganism’s growth. Research limitations/implications: Manufactured linings require additional improvement in mechanical properties by mixing more than one type of additives mentioned in the research. Thus, physical and biological properties can be obtained simultaneously with mechanical properties. Practical implications: The above results qualify the silicone rubber composites for use as a socket liner due to their flexibility and ability to absorb water in addition to their resistance and prevent the growth of fungi and bacteria. Originality/value: The method of preparation and properties of the lining material and additives qualify it for such applications as physical and biological properties.

3

Analysis of the Influence of Hexagonal Boron Nitride on Tribological Properties of Grease

Senyk Szymon, Kałdoński Tadeusz

Tribologia

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2022

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nr 3

101--112

EN

The article discusses the problem of using hexagonal boron nitride (h-BN) as a grease additive. The literature on the subject was analysed in terms of greases into which hexagonal boron nitride was added. Particular attention was paid to the nano h-BN, due to the topicality of this topic and the potential of nano-additives to lubricants noted in published scientific studies. It was found that in order to indicate the regularities describing the tribological interaction of hexagonal boron nitride, detailed studies and an analysis of its properties are required. The important factors determining the application of this additive include particle size distribution, morphology, specific surface area, and porosity. The mentioned properties were determined for four samples of hexagonal boron nitride, which were also objects of tribological experiments. For this purpose, a scanning electron microscope (SEM) and XRD method were used, and low-temperature adsorption isotherms were determined. The research on the influence of h-BN on the lubricity properties of lithium grease was carried out on a four-ball apparatus. Possible mechanisms of interaction of different types of h-BN in the friction zone were identified using the information collected on their important properties. Based on the results of the research, it was found that the use of nano h-BN in the discussed context seems promising.

PL

W artykule podjęto problematykę zastosowania heksagonalnego azotku boru (h-BN) jako dodatku do smarów plastycznych. Przeprowadzono analizę literatury tematu pod kątem smarów plastycznych, do których wprowadzano heksagonalny azotek boru. Szczególną uwagę zwrócono na nanodmianę h-BN, z uwagi na aktualność tej tematyki i odnotowywany w opublikowanych badaniach naukowych potencjał nanododatków do środków smarnych. Stwierdzono, że aby wskazać prawidłowości opisujące tribologiczne oddziaływanie heksagonalnego azotku boru wymagane są szczegółowe badania i analiza jego właściwości. Do istotnych czynników determinujących opisywane zastosowanie tego dodatku zaliczono: rozkład rozmiarów jego cząstek, ich morfologię, powierzchnię właściwą, a także porowatość. Wymienione właściwości określono dla czterech próbek heksagonalnego azotku boru, które były jednocześnie obiektami eksperymentów tribologicznych. Wykorzystano w tym celu skaningowy mikroskop elektronowy (SEM), metodę dyfrakcji rentgenowskiej (XRD) oraz wyznaczono niskotemperaturowe izotermy adsorpcji. Badania wpływu h-BN na właściwości smarnościowe litowego smaru plastycznego przeprowadzono na aparacie czterokulowym. Zidentyfikowano możliwe mechanizmy oddziaływania różnych typów h-BN w strefie tarcia, wykorzystując przy tym zgromadzone informacje dotyczące ich istotnych właściwości. Na podstawie wyników przeprowadzonych badań stwierdzono, że zastosowanie nano h-BN w omawianym kontekście wydaje się perspektywiczne.