Wyniki wyszukiwania - BazTech

1

The influence of carbide reinforcement on the properties of sintered aluminium alloy matrix composites

Szewczyk-Nykiel Aneta

Technical Transactions

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2023

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Vol. 120, iss. 1

art. no. e2023005

EN

Based on the commercial aluminium alloy powder blend (Alumix 431D) metal matrix composites reinforced with particles of SiC as well as TiC were produced by conventional powder metallurgy technology and the effect of the type and amounts of reinforced particles on the selected properties and microstructure of sintered composites were investigated. In particular, the densification behaviour, the wear resistance and the corrosion resistance in 3.5% NaCl solution were identified. It was stated that both the type and the weight fraction of carbide used as particulate reinforcement have a great impact on the properties of aluminium alloy matrix composites. It was shown that the introduction of titanium carbide has a more favourable effect on the properties of sintered Alumix 431D matrix composites in comparison to silicon carbide and the optimum content of TiC in composite is 4 wt. % due to the highest hardness, wear resistance (wear rate of 2.865·10 ̄ ³ mm³/m) and simultaneously the best corrosion resistance (corrosion rate of 0.005 mm/year).

2

Paint coatings in military applications general characteristics

Michalski Marek

System Safety : Human - Technical Facility - Environment

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2023

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Vol. 5, iss. 1

285--293

EN

The article presents an overview of research conducted on the development of camouflage coating systems in the range of ultraviolet, visible, near infrared and radar waves, as well as operational tests of these systems. Among other things, the influence of temperature on coating systems and tests in chambers with cyclically changing conditions is presented.

3

Properties of WC-Co coatings with Al2O3 addition

Radek Norbert

Production Engineering Archives

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2023

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Vol. 29, Iss. 1

94--100

EN

Properties of WC-Co coatings with Al2O3 addition on the C45 mild steel surface in acidic chloride solution were examined. The WC-Co-Al2O3 coatings on steel surfaces were deposited by an electro-spark (ESD) technique. The anti-corrosion properties of the coatings were mainly investigated by electrochemical methods. Moreover, the scanning electron microscope (SEM) was employed for the observation of the surface of materials. The structure of coatings depended on the composition of electrospark electrodes. In the WC80-Co5-Al2O315 coating, the largest corrosion resistance was shown. The corrosion rate of the specimen was approximately eight times smaller than the coating with out of Al2O3 addition. The aim of the research was to obtain, by adding alumina, an improvement in the functional properties of WC-Co coatings produced by the ESD method. Due to the original features of ESD coatings, they can be used in sliding friction pairs and as anti-wear coatings on cutting tools. C-Co coatings with AlO3 addition.

4

Zinc and graphene oxide composites as new protective coatings for oil and gas pipes

Asghar M. Sajid Ali, Amir Muhammad, Hussain Umer, Sabri Mohammed M.

Polimery

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2023

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Vol. 68, nr 7-8

378--385

EN

A method was developed to obtain a durable coating consisting of zinc and graphene oxide (Zn-GO) in order to reduce the mechanical wear and tear rate of oil and gas pipelines made of steel. Graphene oxide was obtained from graphite by wet chemical oxidation (unmodified and modified Hummers’ method) using potassium permanganate and sulfuric acid. The process was carried out at various temperatures. The steel was covered with an ultrathin layer of Zn-GO using the electrophoretic deposition method. The GO particle size (< 90 nm) was confirmed by XRD and laser analysis. For GO particles obtained by the modified Hummers’ method, a significant correlation was observed in the scratch (R2 = 0.87) and the Vickers microhardness tests (R2 = 0.93), which indicates a lower wear rate of Zn-GO-coated steel.

PL

Opracowano metodę otrzymywania trwałej powłoki składającej się z cynku i tlenku grafenu (Zn-GO) w celu zmniejszenia zużycia mechanicznego rurociągów naftowo-gazowych wykonanych ze stali. Tlenek grafenu pozyskano z grafitu metodą mokrego utleniania chemicznego (niezmodyfikowana i zmodyfikowana metoda Hummersa) z użyciem nadmanganianu potasu i kwasu siarkowego. Proces prowadzono w różnej temperaturze. Stal powlekano ultra cienką warstwą Zn-GO techniką osadzania elektroforetycznego. Metodą XRD i analizą laserową potwierdzono wielkość cząstek GO (≤ 90 nm). Dla cząstek GO otrzymanych zmodyfikowaną metoda Hummersa zaobserwowano znaczącą korelację w teście zarysowania (R2 = 0.87) i mikrotwardości Vickersa (R2 = 0.93), co świadczy o mniejszym stopniu zużycia stali pokrytej powłoką Zn-GO.

5

Investigations of CrN/TiO2 coatings obtained in a hybrid PVD/ALD method on Al-Si-Cu alloy substrate

Staszuk Marcin

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144622

EN

The paper addresses an important scientific topic from the utilitarian point of view concerning the surface treatment of Al-Si-Cu aluminum alloys by PVD/ALD hybrid coating deposition. The influence of the conditions of deposition of titanium oxide in CrN/TiO2 coatings on their structure and properties, in particular corrosion resistance, were investigated. The TiO2 layer was produced by the atomic layer deposition (ALD) method with a variable number of cycles. Structural investigations were performed using scanning and transmission electron microscopy (SEM and TEM), atomic force microscopy (AFM), and Raman spectroscopy methods. Electrochemical properties were analyzed using potentiodynamic and electrochemical impedance spectroscopy (EIS) methods. The CrN/TiO2 hybrid coating with titanium oxide deposited at 500 ALD cycles showed the best corrosion properties. It was also found that the prerequisite for obtaining the best electrochemical properties was the amorphous structure of titanium oxide in the tested hybrid coatings. The high tribological properties of the tested coatings were also confirmed.

6

Influence of annealing conditions on changes of the structure and selected properties of Al88Y7Fe5 and Al88Y6Fe6 alloys

Babilas Rafał, Spilka Monika, Łoński Wojciech, Radoń Adrian, Kądziołka-Gaweł Mariola, Gębara Piotr

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144614

EN

Al-Y-Fe amorphous and nanocrystalline alloys are characterized by a unique collection of diverse properties that are influenced by various factors, including heat treatment. In this paper, the effect of heat treatment on the structural changes and selected properties of Al-Y-Fe metallic glasses in the as-spun state is investigated. The structure of the Al88Y7Fe5 and Al88Y6Fe6 alloys was examined by X-ray diffraction (XRD) and Mössbauer spectroscopy (MS). The corrosion resistance of the samples was characterized using polarization tests in a 3.5% NaCl solution at 25 °C. The effect of sodium chloride on the surface was studied with scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). The magnetic properties of Al-based alloys were explored using a vibrating sample magnetometer (VSM). It was revealed that the tested alloys show better properties after annealing than in the as-spun state. The annealing of the Al88Y7Fe5 and Al88Y6Fe6 alloys in the temperature range of 200 to 300 °C improved the magnetic properties and corrosion resistance of these materials. After 3,600 s, the better EOCP values were recorded for the Al88Y6Fe6 and Al88Y7Fe5 alloys after annealing at 300 °C and 200 °C, adequately. On the basis of the polarization tests, it was concluded that the electrochemical properties are better for Al88Y6Fe6 alloys after annealing at 300 °C.

7

Effect of spray distance on the microstructure and corrosion resistance of WC - based coatings sprayed by HVOF

Jonda Ewa, Łatka Leszek, Maciej Artur, Godzierz Marcin, Gołombek Klaudiusz, Radziszewski Andrzej

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 2

art. no. e144610

EN

Cermet coatings provide protection against aggressive operating environment of machine and device elements, such as corrosion, wear or high-temperature conditions. Currently WC-based cermet coatings are frequently used in the different industry branches. In this work, conventional WC-based powders (WC-Co and WC-Co-Cr) were sprayed with High Velocity Oxy Fuel (HVOF) onto AZ31 magnesium alloy with different spray distances (320 and 400 mm). The aim of the research was to investigate the effect of the spray distance on the microstructure of the coatings, phase composition and electrochemical corrosion resistance. Results revealed that higher spray distance results in greater porosity, 1.9% and 2.3% for 320 mm and 2.8% and 3.1% for 400 mm in case of WC-Co and WC-Co-Cr coatings, respectively. Also the influence has been observed for coatings microhardness, c.a. 1300 HV0.3 for shorter spray distance, whereas for longer one it was less than 1100 HV0.3. The corrosion resistance estimated in potentiodynamic polarization measurements was the best for WC-Co-Cr coating deposited from the shorter spray distance, corrosion current density was equal to 2.9 µA·cm-2 and polarization resistance was equal to 8424 Ω∙cm2.

8

Study on the anti-corrosion properties of hydrophobic cement mortar containing coral sand

Zhao Yayun, Wang Qing, Song Qingnan, Xu Shuangshuang

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 3

art. no. e177, 2023

EN

The high porosity and strong water absorption of coral sand (CS) lead to the decline of the corrosion resistance of CS cement mortar. In this study, an environmentally friendly method of preparing hydrophobic concrete with water-repellent and anti-corrosion properties using CS is proposed. CS was modified by stearic acid to reduce the excessive water absorption caused by its high porosity. The prepared modified CS (M-CS) was used to partially replace the sand in the cement mortar to fabricate hydrophobic cement mortar, the water contact angle of which was found to be 115.9°. The cumulative water absorption, compressive strength, and anti-corrosion properties of hydrophobic cement mortar were explored. The cumulative water absorption of the hydrophobic mortar was found to be 49.75% lower than that of ordinary cement mortar. The compression test results show that a 10% content of M-CS can improve the compressive strength of cement mortar. Moreover, the corrosion resistance was found to be enhanced with the increase of the M-CS content. The hydrophobic cement mortar developed in this study is expected to strengthen the corrosion resistance of cement mortar used for coastal engineering.

9

Polimery w nowym wcieleniu

Wróbel Gabriel

Polimery dla Biznesu

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2022

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nr 4

27--29

PL

W artykule przedstawiono studium produktów przemysłowych – sprężyn pierścieniowych, które dzięki nowym rozwiązaniom materiałowym pozwalają poszerzyć obecnie stosowane charakterystyki podobnych elementów konstrukcyjnych wykonywanych z wysokojakościowych stali [1-4]. Własności materiałów polimerowych, w połączeniu z odpowiednio dobraną postacią konstrukcyjną oraz wymiarami, stwarzają szerokie pole dla zastosowań w układach zarówno statycznych jak i dynamicznych, dzięki możliwościom spełnienia różnych kryteriów użytkowych, obejmujących sztywność, deformację, tłumienie drgań, uderzeń, hałasu. Oferują jednocześnie właściwe polimerom zalety odporności na korozję, technologiczności, ale również gęstość masową w porównaniu do stali.

EN

The article presents a study of industrial products - ring springs, which, thanks to new material solutions, make it possible to expand the currently used characteristics of similar structural elements made of high-quality steels [1-4]. The properties of polymeric materials, combined with appropriately selected structural form and dimensions, create a wide field for applications in both static and dynamic systems, thanks to their ability to meet various performance criteria, including stiffness, deformation, damping of vibrations, impacts, noise. At the same time, they offer the inherent advantages of polymers in corrosion resistance, technologicity, but also mass density compared to steel.

10

The role of the chemical composition of trivalent passivation bath for aluminum 5005A series in shaping the morphology of conversion coating and corrosion resistance

Gralak Eryk, Hoffman Adrianna, Winiarski Juliusz

Ochrona przed Korozją

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2022

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nr 6

177--181

EN

5005A series aluminum samples were passivated to obtain a conversion coating based on Cr(III) compounds. It was shown that the corrosion resistance of galvanized aluminum in a bath containing both zirconium and cobalt compounds, measured in a 0.05 M NaCl solution, slightly increased compared to the corrosion resistance of aluminum as delivered, i.e. without conversion coating. In the case of galvanic treatment of aluminum in baths containing separately cobalt or zirconium compounds, a significant increase in corrosion resistance was achieved in relation to aluminum in the delivered condition. SEM analysis showed that in the presence of the simultaneous addition of zirconium and cobalt compounds, the most developed surface was created compared to the addition of only zirconium, where bright spheroidal precipitates occur locally. EDS analysis showed the presence of : C, O, Mg, Al and Si, small amounts of Cr, Zr, F on the surface of the aluminum covered with the Cr + Zr + HF conversion coating. During measurements with the use of the linear polarization resistance (LPR) technique, the best anti-corrosion properties were demonstrated by the samples that were passivated in a Cr(III) solution with the addition of Zr compound and HF and in a Cr(III) solution with the addition of Co compound and HF.

PL

Próbki aluminium serii 5005A poddano procesowi pasywacji z wytworzeniem powłoki konwersyjnej na bazie związków Cr(III). Wykazano, że odporność korozyjna aluminium poddanego obróbce galwanicznej w kąpieli zawierającej jednocześnie związki cyrkonu i kobaltu, mierzona w 0,05 M roztworze NaCl, nieznacznie wzrosła w stosunku do odporności korozyjnej aluminium w stanie dostarczenia, tzn. bez powłoki konwersyjnej. W przypadku obróbki galwanicznej aluminium w kąpielach, które zawierały osobno związki kobaltu lub cyrkonu, uzyskano wyraźny wzrost odporności korozyjnej w stosunku do aluminium w stanie dostarczenia. Analiza SEM wykazała, że w obecności jednocześnie dodatku cyrkonu i kobaltu powstała najbardziej rozwinięta powierzchnia. W przypadku zastosowania tylko dodatku cyrkonu jasne wytrącenia sferoidalne występują lokalnie. Analiza EDS wykazała obecność C, O, Mg, Al i Si, niewielkich ilości Cr, Zr, F na powierzchni aluminium pokrytego powłoką konwersyjną Cr + Zr + HF. Podczas pomiarów techniką liniowego oporu polaryzacji (LPR) najlepsze właściwości antykorozyjne wykazały próbki poddane pasywacji w roztworze Cr(III) z dodatkiem związków Zr i HF oraz w roztworze Cr(III) z dodatkiem związków Co i HF.

11

Porównanie mikrostruktury i odporności na korozję powłok natryskiwanych metodą HVOF (high velocity oxy fuel) na podłoże ze stopu magnezu

Jaworska Justyna, Gruszka Magdalena, Nabrdalik Monika, Marcinkowski Marcin, Mikołejko Wojciech, Augustyn Ewelina, Jonda Ewa, Maciej Artur, Kiljan Anna

Ochrona przed Korozją

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2022

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nr 4

112--123

PL

Stopy magnezu ze względu na korzystny stosunek niskiej masy do dobrych własności mechanicznych coraz powszechniej są stosowane w przemyśle. Przeszkodę w ich aplikacji może stanowić reaktywność chemiczna magnezu, a więc jego wysoka podatność na korozję. Powłoki natryskiwane cieplnie metodą HVOF (high velocity oxy fuel) pozwalają wytworzyć szczelną barierę pomiędzy materiałem podłoża a środowiskiem, dzięki czemu mogą stanowić skuteczną ochronę stopów magnezu. W artykule przedstawiono wyniki badań mikrostruktury oraz wybranych własności dwóch powłok natryskiwanych przy wykorzystaniu komercyjnych proszków WC-Co i WC-Cr3C2-Ni metodą HVOF na podłożu ze stopu magnezu AZ91. Celem pracy było porównanie mikrostruktury, wybranych własności oraz odporności na korozję wytworzonych powłok. Na podstawie wyników badań mikroskopowych stwierdzono, że powłoki charakteryzują się zwartą mikrostrukturą, a twarde cząstki WC oraz Cr3C2 są równomiernie rozłożone w całej objętości powłoki. Powłoka WC-Co charakteryzuje się ponadto wyższą odpornością korozyjną oraz mikrotwardością, jednak cechuje ją mniejsza wydajność natryskiwania i chropowatość w porównaniu z powłoką WC-Cr3C2-Ni.

EN

Due to the promising ratio of low weight to good mechanical properties, magnesium alloys are more and more widely used in industry. An obstacle in their application may be the chemical reactivity of magnesium, and therefore its high susceptibility to corrosion. Thermal sprayed coatings with the HVOF (high velocity oxy fuel) method allow creating a tight barrier between the base material and the environment, which can effectively protect magnesium alloys. The article presents the results of research on the microstructure and selected properties of two sprayed coatings with the use of commercial WC-Co and WC-Cr3C2-Ni powders using the HVOF method on the substrate made of AZ91 magnesium alloy. The work aimed to compare the microstructure, selected properties, and corrosion resistance of the produced coatings. Based on the results of the metallographic research, it was found that the coatings are characterized by a dense microstructure, and the hard particles of the WC and Cr3C2 are evenly distributed throughout the entire volume of the coating. Also the WC-Co coating is characterized by higher corrosion resistance and microhardness however, it has a lower spray efficiency and roughness compared to the WC-Cr3C2-Ni coating.

12

Initial comparative studies of the anodic polarization of 304 austenitic steel in eutectic solvents containing propylene or ethylene glycol

Marczewski Marek, Frąckowiak Sandra, Winiarski Juliusz

Ochrona przed Korozją

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2022

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nr 4

103--106

EN

This work presents preliminary comparative studies on the process of electrochemical polishing of austenitic 304 steel in two deep eutectic solvents (DES), based on polyols as hydrogen bond donors. The first is the choline chloride and ethylene glycol solvent, known before in the literature, and the second is the rarely discussed choline chloride and propylene glycol solvent. The analyzes showed that in the latter liquid it is possible to achieve similar results as in the first solvent, but without obtaining a full-fledged effect of electrochemical polishing. The process of anodic polarization in each range of current density for each liquid led to an increase in surface roughness and a simultaneous smoothing of the steel microstructure in the case of tested high current densities. For samples subjected to anodic polarization at medium and high current densities, a slight increase in corrosion resistance was observed compared to the chemically etched steel sample.

PL

W pracy zaprezentowano wstępne badania porównawcze nad procesem polerowania elektrochemicznego stali austenitycznej 304 w dwóch rozpuszczalnikach eutektycznych (deep eutectic solvents, DES) opartych na poliolach jako donorach wiązania wodorowego. Pierwszym z rozpuszczalników był znany w literaturze przedmiotu układ złożony z chlorku choliny i glikolu etylenowego, a drugim – rzadko omawiany układ złożony z chlorku choliny i glikolu propylenowego. Wykazano, że w wypadku ostatniej cieczy można osiągnąć podobne wyniki co w tej na bazie glikolu etylenowego, nie uzyskując jednak wyraźnego efektu polerowania elektrochemicznego. Proces polaryzacji anodowej w każdym zakresie gęstości prądu dla każdej cieczy doprowadził do zwiększenia się chropowatości powierzchni przy jednoczesnym wygładzeniu mikrostruktury stali w wypadku ustalonych wysokich gęstości prądu. Stwierdzono drobny wzrost odporności na korozję próbek poddanych polaryzacji anodowej przy średnich i wysokich gęstościach prądu w porównaniu z próbką stalową trawioną chemicznie.

13

Effect of electrochemical treatment in eutectic solvent and deposition of SiO2 sol-gel coating on corrosion resistance of 316L steel in Ringer’s solution

Mazur-Nowacka Anna, Marczewski Marek, Tylus Włodzimierz, Szczygieł Bogdan, Chęcmanowski Jacek

Ochrona przed Korozją

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2022

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nr 5

152--156

EN

The 316L stainless steel samples were subjected to anodic polarization in a eutectic solvent and then theSiO2 coatings were deposited on them using the sol-gel method. The coatings were prepared from a sol containing TEOS as a precursor and ethanol as a solvent. The obtained samples were exposed in Ringer’s solution. Studies have shown that electrochemical treatment of 316L steel affects both the morphology, topography and roughness of the metallic material. Potentiodynamic tests showed that the best barrier properties after exposure to Ringer’s solution were obtained for 316L steel subjected to electrochemical treatment, additionally covered with a SiO2 coating. The deposition of the three-layer SiO2 coatings reduces the corrosion current density and an increase in the polarization resistance relative to the uncoated 316L steel.

PL

Próbki ze stali nierdzewnej 316L poddano polaryzacji anodowej w rozpuszczalniku eutektycznym, a następnie metodą zol-żel osadzono na nich powłoki SiO2. Powłoki otrzymywano z zolu zawierającego TEOS jako prekursor i etanol jako rozpuszczalnik. Otrzymane próbki eksponowano w roztworze Ringera. Badania dowiodły, że elektrochemiczna obróbka stali 316L wpływa zarówno na morfologię oraz topografię, jak i chropowatość materiału metalicznego. Potencjodynamiczne badania wykazały, że najlepsze właściwości barierowe po ekspozycji w roztworze Ringera uzyskano dla stali 316L poddanej obróbce elektrochemicznej i dodatkowo pokrytej powłoką SiO2. Osadzenie trójwarstwowych powłok SiO2 powoduje zmniejszenie gęstości prądu korozji oraz wzrost oporu polaryzacji względem niepokrytej stali 316L.

14

Corrosion Behavior of FeAl and Fe3Al Based Fe-Al-C Alloys in Sulfuric Acid

Silva A. P., Brito P. P., Martins N.

Archives of Foundry Engineering

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2022

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Vol. 22, iss. 2

77--82

EN

Iron aluminides are iron-aluminum alloys that have excellent resistance to oxidation at high temperatures with low density, high resistance/weight ratio and a low manufacturing cost. Due to its characteristics, these alloys are presented as an option to replace stainless steels in certain applications. This works intends report the casting process and subsequent analyses involving microstructure, mechanical properties, and corrosion resistance of two Fe-Al-C alloys (Fe-11wt%Al and Fe-25wt%Al, containing 0.31-0.37%C), which were prepared in an induction furnace and poured in a permanent mold. Samples of these alloys were characterized and presented elevated hardness values of 37 HRC (alloy Fe-11wt%Al) and 49.6HRC (alloy Fe-25wt%Al) and microstructure with aluminides type Fe3Al and FeAl and also carbides type K. The Fe-11wt%Al alloy exhibited superior resistance to uniform corrosion, although both Fe-Al-C alloys exhibited significantly higher corrosion rates compared to a binary iron aluminide in 0.5M H2SO4 containing naturally dissolved oxygen.

15

Characterization of microstructure, corrosion, and tribological properties of a multilayered friction surfaced Al–Mg–Si–Ag alloy

Pirhayati Parisa, Aval Hamed Jamshidi, Loureiro Altino

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 4

art. no. e176, 2022

EN

In this research, an Al–Mg–Si–Ag multilayered coating with different amounts of silver additive was deposited on the AA2024 substrate using the friction surfacing process to investigate the microstructure, corrosion, and wear characteristics of the structure. The results showed that the silver-containing coating layer had a lower deposition rate and efficiency than coating without the silver additive. Owing to the lower temperature than silver-free coating and the presence of silver-rich particles acting as a barrier to grain boundary movement, no significant difference was found in grain size of different layers of the silver-containing coating. After aging heat treatment of the silver-containing coating, the Q (Al4(Cu, Ag) Mg4Si4) precipitates were formed as part of the silver-rich particles began to dissolve. After aging heat treatment, the top layer of the silver-containing coating showed 16% higher hardness than the AA2024 substrate. The wear rate of coating containing 13 wt% silver was 37% lower than the AA2024 substrate. The corrosion current density was reduced by approximately 97% and 99% in the silver-containing sample as compared to the sample devoid of silver and AA2024 substrate. With increasing silver content in the coated layer, the wear mechanism transitions from a combination of abrasive and adhesive wear mechanisms to an abrasive wear mechanism.

16

Accumulative roll bonding fabrication, tensile and corrosion characterization of Zn/Al multilayered composites

Mosafajahanabad Nasim, Alizadeh Morteza, Salahinejad Erfan

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 4

art. no. e191, 2022

EN

In the present work, accumulative roll bonding (ARB) processing and characteristics of Zn/6 wt% Al multilayered composite sheets were investigated for the first time. The structure of the fabricated composites was evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Tensile testing and fractography were used to assess the strength and elongation of the composites. The corrosion behavior of the fabricated samples was also investigated by potentiodynamic polarization and electrochemical impedance spectroscopic tests in the 3.5 wt% NaCl solution. Despite the evolution of atomic intermixing at the interface of the layers and grain refinement, the tensile strength and elongation of the composites were reduced by increasing ARB cycles due to the domination of plastic instability introduced by the ARB process. In addition, an initial increase until the third ARB cycle followed by decrease in the corrosion tendency of the composites was found by progression of the ARB process, which was attributed to a compromise between the levels of structural defects and homogeneity. It is eventually concluded that after optimizing the mechanical and corrosion behaviors as a function of the number of ARB cycles, ARB-processed Zn/Al multilayered composites can be further considered in industrial applications.

17

Odporne na korozję, wrażliwe na temperaturę [rury wodociągowe]

Mierzyński Szczęsny

Wodociągi - Kanalizacja

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2021

|

nr 4

21--24

18

Zamykacze drzwiowe

Czajka Zbigniew

Świat Szkła

|

2021

|

R. 26, nr 1

20--22

19

EHLA Tuning: Powlekanie wałków do 200 metrów na minutę

Świat Obrabiarek i Narzędzi

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2021

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R. 16, nr 1

6

20

On the anodic polarization of 316 steel in a choline chloride : ethylene glycol deep eutectic solvent and its impact on the surface topography and corrosion resistance

Winiarski Juliusz, Marczewski Marek, Urbaniak Martyna

Ochrona przed Korozją

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2021

|

nr 1

3--7

EN

This work presents the possibility of the use of a deep eutectic solvents (DES) in the electropolishing process for 316 austenitic stainless steel, instead of highly aggressive conventional sulphate baths. The main emphasis was on finding some relationships between the anodic polarization parameters of the 316 steel, and its surface morphology, topography and corrosion resistance. It has been shown that an increase in the bath temperature from 25 to 65°C accelerates dissolution kinetics of 316 steel in a DES composed of choline chloride and ethylene glycol. The anodic polarization at a current density 15 mA cm–2 for 5 min resulted in removal of the scratches from previous mechanical polishing. By increasing the current density from 15 to 25 mA cm–2, some visual surface levelling was obtained – austenite grains became visible, and the selective etching of grain boundaries has not been observed. Although the samples after anodic polarization were characterized by Ra = 78 ±27 nm (at 15 mA cm–2) and Ra = 96 ±37 nm (at 25 mA cm–2), so a bit higher than Ra for as-supplied steel (43 ±11 nm), the anodic polarization has increased their corrosion resistance in 0.5 mol dm–3 NaCl corrosive environment. The highest polarization resistance (Rp = 2.1-2.4 MΩ cm2 after 22-24 hrs of exposure) was calculated for the steel polarized at 15 mA cm–2 for 5 min. Increasing the current density from 15 to 25 mA cm–2 did not impair the corrosion resistance and resulted in significant broadening of the passive region of this steel during registering the potentiodynamic polarization curves in 0.5 mol dm–3 NaCl.

PL

W pracy zaprezentowano możliwość użycia rozpuszczalników eutektycznych (deep eutectic solvents, DES) w procesie polerowania elektrochemicznego stali austenitycznej 316, w zastępstwie konwencjonalnych i agresywnych kąpieli siarczanowych. Uwagę skupiono na znalezieniu powiązań między parametrami procesu polaryzacji stali 316 a morfologią powierzchni, topografią i odpornością na korozję. Wykazano, że wzrost temperatury kąpieli z 25 do 65°C wpływa na wzrost szybkości roztwarzania stali 316 w rozpuszczalniku DES złożonym z chlorku choliny i glikolu etylenowego. Polaryzacja anodowa przy gęstości prądu 15 mA cm–2 w czasie 5 min spowodowała wyraźne usunięcie rys powstałych po mechanicznym szlifowaniu powierzchni. Poprzez zwiększenie gęstości prądu z 15 do 25 mA cm–2, uzyskano pewne wizualne wyrównanie powierzchni – ziarna austenitu zostały ujawnione, a jednocześnie nie zaobserwowano selektywnego roztwarzania w obrębie ich granic. Pomimo że po polaryzacji anodowej stal charakteryzowała się chropowatością Ra = 78 ±27 nm (przy 15 mA cm–2) i Ra = 96 ±37 nm (przy 25 mA cm–2), a więc nieco więcej niż wartość Ra w stanie dostarczenia (43 ±11nm), to polaryzacja w rozpuszczalniku DES zwiększyła jej odporność na korozję w 0,5 mol dm–3 roztworze NaCl. Najwyższą wartość rezystancji polaryzacji (Rp = 2.1-2.4 MΩ cm2 po 22-24 godzinach ekspozycji) obliczono dla stali polaryzowanej przy 15 mA cm–2 przez 5 min. Zwiększenie gęstości prądu z 15 do 25 mA cm–2 nie pogorszyło odporności na korozję, a skutkiem tego było poszerzenie zakresu pasywnego w trakcie rejestracji krzywych polaryzacyjnych w 0,5 mol dm–3 roztworze NaCl.