Wyniki wyszukiwania - BazTech

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Investigation of SiC Particle Size Variation on the Tribological Properties of Cu-6Sn-SiC Composite

Shankar K. V., Chandroth A. M., Ghosh K. J. A., Sudhin C. B., Pai A. S., Biju A., Sriram K. R.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 4

133--138

EN

Copper have always been an important material and incorporation of elements into copper for property enhancement. Bronze is a relevant cuprous alloy which is important for many industrial and automotive applications like bearings and machineries. The present research is directed towards the fabrication and tribological analysis of regular bronze (Cu-6Sn) and metal matrix composites reinforced with varying particle sized SiC ceramic reinforcement (30, 35 and 40 μm). The developed specimens were subjected to wear analysis according to ASTM standards, to identify the tribological properties utilizing a pin on disk tribometer. It was noted that the wear rates of developed MMC’s phenomenally decremented with an increase in size of SiC particle reinforcement. Also, the test parameters were influential in altering the wear rates to notable margins. The standard scanning electron microscopy techniques aided in identifying the influence of adhesive wear on the specimen surface.

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Corrosion Behaviour of CuSn- and CuZnNi-coated Polypropylene Nonwoven

Dobruchowska E., Koprowska J.

Fibres & Textiles in Eastern Europe

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2016

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Vol. 24, no. 3 (117)

72--78

EN

The intended purpose of metallised nonwovens is architectural shielding against electromagnetic fields. Therefore the aim of this work was to systematically investigate the corrosion behaviour of metallic layer/polypropylene nonwoven systems in the contact with an aggressive environment (3% NaCl solution). In the work, a thermo-bonded polypropylene nonwoven was used as a substrate for CuSn and CuNiZn thin layer deposition. Nonwoven metallisation was carried out using the magnetron sputtering process. Additionally to enhance the durability of these barrier materials, their surfaces were covered with a thin, hydrophobic coating of polydimetylsiloksane. Evaluation of the corrosion resistance was made by means of potentiodynamic polarisation tests. Furthermore the degree of loss of the metallic layers was checked using a optical metallographic microscope and quantitative microanalysis by the method of Energy Dispersive X-ray Spectroscopy. It was found that the CuZnNi metallic layer deposited onto the polypropylene nonwoven shows higher corrosion resistance as compared to CuSn. In both cases, the metallic layers are the most susceptible to degradation within the nonwoven “waves”. Regardless of the layers’ chemical composition, the polydimetylsiloksane coating increases their corrosion resistance in 3% NaCl solution.

PL

W ramach pracy, jako podłoże dla cienkich warstw metalicznych CuSn i CuNiZn wykorzystana została włóknina polipropylenowa. Metalizację włókniny przeprowadzono stosując proces rozpylania magnetronowego. Zakłada się, że przeznaczeniem tak uzyskanych metalizowanych włóknin będzie ekranowanie architektoniczne przed polami elektromagnetycznymi. Z tego względu, jako cel pracy przyjęto przeprowadzenie systematycznych badań mających na celu określenie sposobu zachowania się układów warstwa metaliczna/ włóknina polipropylenowa w kontakcie z agresywnym środowiskiem korozyjnym (3% roztwórem NaCl). Dodatkowo, aby zwiększyć trwałość uzyskanych materiałów barierowych, ich powierzchnie pokryto cienką hydrofobową powłoką poli(dimetylosiloksanu). Ocena odporności korozyjnej przeprowadzona została za pomocą polaryzacyjnych testów potencjodynamicznych. Ponadto, stopień degradacji warstw metalicznych sprawdzano z wykorzystaniem optycznego mikroskopu metalograficznego oraz ilościowej mikroanalizy rentgenowskiej (EDX).

3

Examples of thermal derivative gradient analysis (TDGA) application

Cholewa M., Suchoń J., Kondracki M.

Archives of Foundry Engineering

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2009

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Vol. 9, iss. 4

23-30

EN

The study presents the possibility of TDGA method based on multipoint measurement of temperature during crystallization of two test castings poured from different temperature. Sample castings have conical shape. Temperature measurement is carried out in six cone cross-sections between the heat axis and the surface of the mould cavity. The multichannel recording device allows describing the thermal derivative after time and direction. Presented examples of the assessment of kinetics of crystallization for alloys: AlSi11, CuSn8 and GJL 200 cast iron. Based on quantitative analysis of the microstructure (DAS, fig. 1 and tab.1) examples of relations were prepared, describing the mechanical and structural properties in function of crystallization kinetics parameters - DAS = f(vchł) DAS = f(\delta(dT/dt)/dt) HV = f(Gy) Rm = f(\delta(dT/dt)/dt) as shown in fig. 2 and 4. The evaluation of crystallization process was also conducted for AlSi11 skeleton castings. Pointed out was the universality of the method with respect to the mathematical interpretation of the results and its limitations due to data registration extracted from multiple thermocouples. Based on the conducted studies, the method can be applied in the industry as well as in the experimental practice.

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Przenoszenie w procesie tarcia składników samo smarnego kompozytu PTFE do warstwy wierzchniej elementu stalowego

Starczewski L., Szudrowicz M., Szumniak J.

Prace Naukowe Instytutu Konstrukcji i Eksploatacji Maszyn Politechniki Wrocławskiej. Konferencje

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2002

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Vol. 87, nr 27

334-339

PL

W artykule zamieszczono wyniki pomiarów grubości i badań składu chemicznego powłoki na stali 45 hartowanej i stali 45 azotowanej wytworzonej w procesie tarcia z kompozytami zawierającymi: 40% PTFE i 60% brązu oraz 12% PTFE i 12% brązu z lepiszczem żywicy fenolowo - formaldehydowej.

EN

In result of friction the components of PTFE composite create thin coating on steel element. The results of coatings thickness measurements and investigations of chemical analysis are described. During the examinations we used following materials: hardened steel 45, nitrogenized steel 45 and composites - 40% PTFE and 60% of bronze as well as 12% PTFE and 12% of bronze with phenolic - formaldehyde resin.