Wyniki wyszukiwania - BazTech

1

A new chemical mechanical slurry for polishing yttrium aluminium garnet material with magnesium oxide, sodium metasilicate pentahydrate and zirconium dioxide abrasive particles

Duc Le Anh, Hieu Pham Minh, Quang Nguyen Minh

Journal of Machine Engineering

|

2023

|

Vol. 23, No. 2

174--185

EN

This work provided a new chemical-mechanical polishing mixture with MgO, sodium metasilicate pentahydrate, ZrO2 abrasive particles, and deionized water. With chemical-mechanical slurry (CMS) proposed for polishing yttrium aluminum oxide (Y3Al5O12) the surface reaction layer formed with significantly reduced hardness compared to other Y3Al5O12 materials, these products combine with MgO to form montmorillonites (3MgO–Al2O3–3SiO2–3Y2O3–5Al2O3). With this formation, the surface layer of Y3Al5O12 material becomes soft and is easily removed by ZrO2 abrasive particles under the influence of mechanical polishing, resulting in superfine surfaces generated from the proposed CMS model. The experimental results show that the surface quality with CMS proposed gives the surface quality with Ra = 0.471 nm along with the material removal rate 31 (nm/min). Surface quality is improved by 71% along with a superior material removal rate (increased by 287%) compared to silica slurry. The results show excellent polishing ability from CMS proposed for polishing Y3Al5O12 materials.

2

Wpływ cząstek stałych na tendencję oleju napędowego do blokowania filtrów

Żółty Magdalena, Dybich Kornel

Nafta-Gaz

|

2020

|

R. 76, nr 3

205--214

PL

W niniejszym artykule przedstawiono wyniki pracy, której celem było przeprowadzenie szerokich badań w zakresie zawartości zanieczyszczeń olejów napędowych wraz z określeniem klasy czystości oraz tendencji do blokowania filtrów w różnych warunkach temperaturowych. Pozyskano 86 próbek oleju napędowego pobranych na stacjach paliw różnych producentów. Poboru dokonywano z dystrybutorów, ponieważ stanowią one ostatnie ogniwo w łańcuchu dystrybucyjnym, z którego paliwo bezpośrednio trafia do ostatecznego użytkownika, u którego mogą występować problemy związane z awarią układu wtryskowego. Zakres badań obejmował parametry ujęte w specyfikacji PN-EN 590, ze szczególnym uwzględnieniem całkowitej zawartości zanieczyszczeń, oraz badania dodatkowe, takie jak klasa czystości (parametr uwzględniony w Światowej Karcie Paliw), w zakresie cząstek 4, 6 i 14 µm, tendencja do blokowania filtrów w temperaturze pokojowej i w temperaturze −1°C, a także dla wytypowanych próbek – zawartości pierwiastków. Próbki zostały pobrane w okresie od października 2018 roku do lipca 2019 roku. Obejmowały one zarówno okresy przejściowe, jak i letni oraz zimowy. Obecnie w TF (task force) działającej w ramach grupy roboczej WG 24 ds. olejów napędowych (working group) prowadzone są badania zmierzające do wypracowania stanowiska CEN w zakresie problemów związanych z obecnością cząstek stałych w oleju napędowym oraz do określenia limitu klasy czystości i metody oznaczania liczby cząstek celem wprowadzenia jej do specyfikacji EN 590. Analizie podlegają również korelacje pomiędzy liczbą cząstek a parametrami takimi jak tendencja do blokowania filtrów w temperaturze pokojowej i w obniżonej (3 lub −1°C), całkowita zawartość zanieczyszczeń, zawartość wody czy obecność takich pierwiastków jak Fe, Cu i Si. Analiza uzyskanych wyników badań wskazała, że problem zanieczyszczenia paliwa cząstkami stałymi dotyczy dużej grupy olejów napędowych dostępnych na rynku krajowym. Między innymi można wymienić tu zanieczyszczenie tych paliw cząstkami metali, które dostają się do oleju na skutek zużywania powierzchni trących i wraz z zanieczyszczeniami pochodzącymi spoza układu.

EN

This article presents the results of the work, the purpose of which was to conduct extensive research on the content of diesel fuel impurities together with determining the purity class and the tendency to block filters in various temperature conditions. 86 diesel fuel samples of various manufacturers were obtained at gas stations. They were taken from distributors, since the latter constitute the last link in the distribution chain, from which the fuel directly goes to the end user, who may suffer problems related to the failure of the injection system. The scope of tests covered the parameters included in the PN-EN 590 specification, with particular emphasis on the total content of impurities, as well as additional tests, i.e. cleanliness class (parameter included in the World Fuels Card), in the range of particles 4, 6 and 14 µm, tendency to block filters at temperature at room temperature and at –1°C and, for selected samples, of elemental content. Samples were taken from October 2018 to July 2019. They covered both transitional periods as well as summer and winter periods. Currently, TF (Task Force) operating within the WG 24 Working Group on diesel fuels is conducting research aimed at developing the position of CEN on problems related to the presence of solid particles in diesel fuel and determining the purity class limit as well as method for determining the number of particles in order to introduce it into the EN 590 specification. Correlations between the number of particles and parameters such as the tendency to block filters at room temperature and at reduced temperatures (3 or –1°C), total impurities content, water content or the presence of such elements like Fe, Cu and Si are also analyzed. The analysis of the obtained test results allowed to conclude that the problem of particulate fuel pollution concerns a large group of diesel fuels available on the domestic market. Among other things, it can be mentioned that these fuels are contaminated with metal particles that get into the fuel as a result of wear of friction surfaces and together with impurities coming from outside the system.

3

Design and fabrication of Abrasive Jet Machine (AJM)

Rao P. S. V. R., Naidu A. L., Kona S.

Mechanics and Mechanical Engineering

|

2018

|

Vol. 22, nr 4

1471--1482

EN

Abrasive Jet Machining (AJM) is the process of material removal from a work piece by the application of a high-speed stream of abrasive particles carried in a gas or air medium from a nozzle. The material removal process is mainly by erosion. The AJM will chiefly be used to cut shapes in hard and brittle materials like glass, ceramics etc. the machine will be automated to have 3 axes travel. The different components of AJM are Compressor, Vibrator, dehumidifier, Pressure Regulator, and Dust filter, Nozzle, Pressure gauge etc. The different components are selected after appropriate design calculations. In paper contains the Abrasive Jet Machine design and fabrication by using available hardware and software etc. taking into consideration of commercially available components. Care has been taken to use less fabricated components rather than directly procuring them, because, the lack of accuracy in fabricated components would lead to a diminished performance of the machine.

4

Angle of incidence influence of abrasive particles on wear magnitude of hard facings metals

Jankura D.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

|

2002

|

z. 58 [193]

109-114

EN

The contribution presents the results of the research of resistance of hard facing metals in conditions of erosive wear. Two types of hard - surfacing electrodes with different chemical composition were used on creation of three layers hard facing metals. Chemical composition of electrodes determined difference in structure of surface deposit. We investigated the influence of angle of incidence of abrasive particles on wear magnitude of hard facing metals. The results of the experiments showed that intensity of wear is very depended on parameters of wear as well as structure morphology of hard facing metals.