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1

Influence of aluminum alloys surface treatment on the durability of glued joints

Kowalik Joanna, Tworek Magdalena, Smaruj Michał

Polimery

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2023

|

Vol. 68, nr 10

523--529

EN

The aim of the work was to analyze the method of preparing the aluminum surface in terms of the functional properties of glued joints with the use of one-component polyurethane adhesive. Six methods of surface treatment of EN AW-5251 aluminum alloy were tested. In addition, changes in the shear strength of adhesive joints after environmental exposure were determined. The best surface preparation processes were atmospheric plasma and anodizing.

PL

Celem pracy była analiza sposobu przygotowania powierzchni aluminium pod kątem właściwości użytkowych połączeń klejonych z zastosowaniem jednoskładnikowego kleju poliuretanowego. Zbadano sześć metod obróbki powierzchni stopu aluminium EN AW-5251. Ponadto określono zmiany wytrzymałości połączeń klejonych na ścinanie po ekspozycji środowiskowej. Najlepszym sposobem przygotowania powierzchni była plazma atmosferyczna i anodowanie.

2

Effect of carbon fiber surface treatment with HNO3 and KOH on the interfacial bonding of PMMA resin composite

Jian Li

Materials Science Poland

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2023

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Vol. 41, No. 2

301--310

EN

This work studied the surface, interface state and physicochemical properties of HNO3-treated and KOH-treated carbon fiber. Poly(methyl methacrylate) (PMMA) composites were prepared by the autoclave molding process using surface-treated carbon fiber as reinforcements. The physical and chemical states of the carbon fiber surfaces and the micro-interface properties and interlaminar shear properties of the composites were studied. The results show that the surface of the HNO3-treated carbon fiber has more groove structure and higher surface roughness and thus forms a better physical bond with the resin matrix. Although the oxygen-containing functional groups of the two carbon fibers are equivalent, the surface oxygen of the HNO3- treated carbon fiber is relatively high, which is beneficial to form a better chemical bond with the matrix resin, and the interfacial shear strength is about 14% higher than that of the KOH-treated carbon fiber composite.

3

Casting of Combustion Engine Pistons Before and Now on the Example of FM Gorzyce

Czerepak Mateusz, Piątkowski Jarosław

Archives of Foundry Engineering

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2023

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Vol. 23, iss. 2

58--65

EN

The article discusses the most important changes in the construction of permanent mould casting machines, as well as the method of casting engine pistons and their construction on the example of Federal-Mogul (FM) Gorzyce. The system of automatic cooling of the presently used permanent mould casting machines coupled with robots which pour the liquid alloy ensures uniform crystallization of the pistons and optimal efficiency of the casting process. As a result of the necessity to improve the engine efficiency and thus reduce the fuel consumption and harmful substance emission, the construction of the pistons has changed as well. The piston castings, which are produced by gravity casting for metal moulds, have undergone a diametric transformation. Typical piston designs for gasoline and Diesel engines are shown together with the most important parts of the piston, the crown (combustion chamber) and the guide part (skirt). Depending on the type of engine, the present pistons characterize in differently shaped crown, a slimmed internal construction as well as component participation (cooling channels and ring inserts), and the piston skirts undergo surface treatment procedures.

4

Investigation on the effect of silane coupling agent treatment of steel fibers on the durability of UHPC

Du Shuang, Luan Congqi, Yuan Lianwang, Du Peng, Zhou Zonghui, Wang Jinbang

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e118, 2023

EN

Ultra-high performance concrete (UHPC) is a type of cementitious material that has been specifically engineered to achieve exceptional mechanical properties and durability through optimized particle filling. However, the addition of steel fibers to the UHPC matrix creates a transitional region at the interface. Previous research has indicated that the use of silane coupling agents (SCA) on the surface of steel fibers is a promising approach for improving the bonding properties between the fibers and the matrix. This study aims to explore the impact of varying amounts of untreated steel fibers versus those that have undergone SCA treatment on the durability of UHPC. The findings indicate that treating steel fibers with SCA significantly narrows the pore space between the matrix and steel fibers, as well as enhances the production of hydration products on the steel fiber surface. Furthermore, this treatment facilitates the formation of a compact transition zone between the UHPC matrix and steel fibers. The electrochemical corrosion resistance, chloride ion penetration resistance, frost resistance, and sulfate erosion resistance of UHPC are all enhanced by this method. As a result, the durability of UHPC is significantly improved, making it an extremely promising avenue of research.

5

Treatment of Surface Treatment Effluents by Electrocoagulation Process Using Aluminium Electrodes

Namoussi Soukaina, Merbouh Chaimaa, Kabriti Mohamed, Nahli Abdelmottalib, Naamane Ayoub, Chlaida Mohamed, Iounes Nadia

Journal of Ecological Engineering

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2022

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Vol. 23, nr 1

91--99

EN

The surface treatment industry generates effluents with a high load of highly toxic chemicals which must be treated under increasingly stringent regulation. The aim of this study was to treat the effluents of surface treatment unit of an aeronautical industry by the electrocoagulation process using aluminium electrodes. This process is used to study the performance to remove colloidal load, significant amount of oxidizable material and high levels of various metal elements (Cr, Fe, Zn, Cu and Al) from these effluents, under optimum conditions of pH 7, 8.6A of current intensity and 60 min of application. The electrocoagulation process was found to be effective in reducing turbidity (97.12%), COD (97.5%), SS (97.84%) and conductivity (96.82%), hexavalent chromium (99.99%), Zn (96.82%), Cu (94.3%), Iron (99.9%), Al (91.96%). The treated effluent conformed to the Moroccan standards of surface treatment discharge.

6

Reflectivity of anodised Al-Si alloy surface of belt pulleys used in combustion engines

Labisz Krzysztof

Zeszyty Naukowe. Transport / Politechnika Śląska

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2021

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z. 112

125--133

EN

The recent trend of using aluminium alloys instead of steel has reached the transportation industry, where increasingly, more parts are made of aluminium. An example is the belt pulley, applied for combustion engines for energy transmission. This part should be strong, durable, and lightweight. Aluminium-silicon alloys are a good choice, moreover, even when the surface is anodised, also because of their moderate inertia control and excellent wear characteristic during mechanical operations. Since aluminium is lightweight yet mechanically durable and anodised, it is an ideal belt pulley to use, especially in high-temperature operations. However, the main question is what type of Al-Si alloy, casting method and anodisation method should be used in terms of energy adsorption, having long-term properties for a lifetime, has to be applied. For this reason, this paper presents the influence of the chemical composition, casting method and anodising parameters on the structure and thickness of the anodic layer produced on aluminium alloys, as well as on the albedo value as an ability to reflect or absorb light. The aluminium alloys, AlSi12Cu1 and AlSi9Cu3, were used as research materials, obtained using different casting methods. The goal of this work was to determine the optimal combination of the anodisation conditions and materials for maximising the reflectivity factor of the surface, as a very important factor, determining the energy amount absorbed by an anodised surface. For further improvement of these surface properties as well as for enhancement of the properties and strengthen the material produced with different aluminium alloys production methods, different alloying additives were added. In addition, the mechanical properties of the surface layer were measured, where a remarkable hardness increase was obtained, and the best combination in form of AlSi12Cu1 high pressure cast was found with the highest albedo factor among all tested surface variants.

7

Effect of the surface treatment on the strength of the single-lap adhesive joints

Doluk Elżbieta, Rudawska Anna, Stančeková Dana

Technologia i Automatyzacja Montażu

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2021

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nr 1

18--22

PL

W artykule przeanalizowano wytrzymałość na ścinanie jednozakładkowych połączeń klejowych wykonanych z ocynkowanej powłoki blachy stalowej. Obróbkę mechaniczną próbek przeprowadzono przy użyciu papierów ściernych P120, P180, P220, P400 i P600. W eksperymencie zastosowano dwa warianty obróbki powierzchni: z odtłuszczaczem i bez odtłuszczacza. Do wykonania połączeń użyto dwuskładnikowego kleju epoksydowego Epidian 53/IDA/100:40. Badania wytrzymałościowe przeprowadzono na maszynie wytrzymałościowej Zwick/Roell Z150, norma PN-EN 1465. W artykule zamieszczono również wyniki pomiaru siły maksymalnej oraz wartości parametrów chropowatości powierzchni (Ra, Rz, Rq) próbek przygotowanych bez odtłuszczacza. Pomiary parametrów chropowatości powierzchni (Ra, Rz, Rq) wykonano przy użyciu profilometru HOMMEL TESTER T1000, zgodnie z normą PN-EN ISO 4287. Maksymalną wartość wytrzymałości na ścinanie (2,70 MPa) uzyskano dla próbek przygotowanych papierem ściernym P220 z użyciem odtłuszczacza, a najmniejszą (1,02 MPa) dla próbek przygotowanych papierem ściernym P180 z użyciem odtłuszczacza.

EN

The paper analyzed the shear strength of the single-lap adhesive joints made of zinc galvanized coat of steel sheet. Mechanical treatment of the samples was carried out using P120, P180, P220, P400 and P600 abrasive papers. In the experiment were used two variants of surface treatment: with a degreaser and without a degreaser.A two-component epoxy adhesive Epidian 53/IDA/100:40 was used to make the joints.The strength tests were carried out on a Zwick/Roell Z150 testing machine, PN-EN 1465 standard. The article contains also the results of the maximum force and the values of the surface roughness parameters (Ra, Rz, Rq) of the samples prepared without a degreaser. The measurements of surface roughness parameters (Ra, Rz, Rq) were made using a HOMMEL TESTER T1000 profilometer, according to PN-EN ISO 4287. The maximum value of the shear strength (2.70 MPa) was obtained for the samples prepared with P220 abrasive paper using a degreaser and the lowest (1.02 MPa) for the samples prepared with P180 abrasive paper using a degreaser.

8

Interaction of N with White-solidified Cast Iron Model Alloys: The Effect of Mn and Cu on the Formation of Fe and Si Nitrides

Kante Stefan, Leineweber Andreas

Journal of Casting & Materials Engineering

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2021

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Vol. 5, no. 4

66--70

EN

Surface remelting and subsequent nitriding improves the surface properties of cast irons. Upon remelting, a white-solidified surface layer forms, which contains coarse Si-free eutectic cementite (θ) and Si-enriched ferrite, pearlite or martensite in the intercarbidic regions between the eutectic θ. Nitriding produces a compound layer at the surface, which is composed of ε and γ’-iron (carbo)nitrides and enhances the corrosion resistance. Nitriding of white-solidified Fe-C-Si alloys, being model materials for remelted low-alloy ferritic cast irons, has shown that Si dissolved in α-Fe notably affects the formation of ε and γ’ in intercarbidic regions while Si simultaneously precipitates as amorphous nitride, X. Under process conditions only allowing for the formation of γ’ in pure Fe, Si dissolved in α-Fe promotes the formation of ε over the formation γ’, whereas Si-free eutectic θ transforms into nitride following the sequence θ → ε → γ’. The present work studies the nitriding of white-solidified Fe-3.5wt.%C-3wt.%-M alloys with additions of M = 1 wt.% Mn, 1 wt.% Cu or 1 wt.% Mn + 1 wt.% Cu, serving as model materials for remelted pearlitic cast irons. The presence of Mn and/or Cu causes notable deviations from the nitriding behavior known from Fe-C-Si alloys. Mn accelerates the precipitation of X in intercarbidic regions and obstructs the transformation of ε formed from Si-free θ into γ’. Cu promotes the formation of γ’ in Si-rich intercarbidic regions, surpassing the ε-promoting effect of Si.

9

Powierzchniowe utrwalenie jako zabieg utrzymaniowy istniejącej nawierzchni

Przeworska Marzena

Drogi Publiczne

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2021

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nr 4

40--43

PL

Powierzchniowe utrwalenie (PU) to powszechnie znana technologia „na zimno” dedykowana zwłaszcza dla dróg o niższym natężeniu ruchu. Jest to prosty zabieg wykorzystujący emulsję asfaltową oraz kruszywo. Polega na skropieniu nawierzchni lepiszczem, jakim jest emulsja i zasypaniu jej odpowiednim kruszywem oraz uformowaniu mozaiki kruszywowej walcem. Poszczególne elementy prac można stosować w dowolnej konfiguracji omówionej w dalszej części artykułu oraz w wybranym zwielokrotnieniu. O sposobie aplikacji i ilości zużytych materiałów decydować będzie zamawiający oraz wykonawca w porozumieniu z zamawiającym, tak aby optymalnie dobrać materiały oraz rodzaj powierzchniowego utrwalenia do budżetu.

10

Study on Improvement of Surface Properties of Low Carbon Steel Using Laser Cladding

Kim Cheol-Woo, Yoo Hyo-Sang, Jeon Jae-Yeol, Cho Kyun-Taek, Choi Se-Weon

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 4

1033--1036

EN

Laser cladding is a method that can be applied to repair the crack and break on the mold and die surfaces, as well as generate new attributes on the surface to improve toughness, hardness, and corrosion resistance. It is used to extend the life of the mold. It also has the advantages of superior bonding strength and precision coating on a local area compared with the conventional thermal spraying technology. In this study, we investigated the effect of cladding on low carbon alloy steel using 18%Cr-2.5%Ni-Fe powder (Rockit404), which showed high hardness on the die surface. The process conditions were performed in an argon atmosphere using a diode laser source specialized for 900-1070 nm, and the output conditions were 5, 6, and 10 kW, respectively. After the cladding was completed, the surface coating layer’s shape, the hardness according to the cross-section’s thickness, and the microstructure were analyzed.

11

Surface treatment of incrementally produced components in FFF (Fused Filament Fabrication) technology

Mrówka Maciej, Machoczek Tomasz, Szymiczek Małgorzata, Gągol Przemysław, Duda Sławomir, Marcoll Łukasz

Polimery

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2020

|

T. 65, nr 1

51--59

EN

The aim of the conducted research was to examine the possibility of using chemical and physical methods of surface treatment of elements printed on a 3D printer. Elements were printed from polylactide (PLA) and acrylonitrile-butadiene-styrene (ABS) – materials most commonly used in fused filament fabrication (FFF) technology. Roughness measurements were made to assess the quality of individual methods. The best surface smoothness results were obtained during abrasive paper processing and after applying epoxy resin. The intended effect was also obtained after processing samples from PLA in chloroform fumes, and ABS samples in acetone vapors.

PL

Zbadano możliwości wykorzystania chemicznych i fizycznych metod obróbki powierzchniowej elementów wydrukowanych za pomocą drukarki 3D. Elementy wytworzono z polilaktydu (PLA) i kopolimeru akrylonitrylo-butadieno-styrenowego (ABS) – materiałów najpowszechniej stosowanych w technologii Fused Filament Fabrication (FFF). Jakość wykonania przy użyciu poszczególnych metod oceniano na podstawie chropowatości powierzchni wytworzonych elementów. Najlepszą gładkość powierzchni uzyskano w wyniku obróbki wydrukowanych elementów papierami ściernymi i nałożeniu żywicy epoksydowej. Zamierzony efekt uzyskano też w wyniku obróbki próbek z PLA w oparach chloroformu, a próbek z ABS w oparach acetonu.

12

Additive manufacturing of polyether ether ketone – PEEK parts with surface roughness modification by a laser beam

Krolikowski Marcin, Przestacki Damian, Chwalczuk Tadeusz, Sobolewska Ewa, Tomasik Malgorzata

Journal of Machine Engineering

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2020

|

Vol. 20, No. 3

117--124

EN

The physicochemical properties of polyether ether ketone (PEEK) allow to use this material for prosthetic restorations applied in implant prosthetics. So far, such attempts have been made in the technology of milling rough material solids of this polymer, but the surface quality was unsatisfactory. Therefore, the production of these materials by additive manufacturing techniques was proposed and an attempt was made to shape their surface using a laser. The possibilities of the method are determined in the paper and preliminary works related to the product surface shaping are presented. The process of making individual prosthetic restorations from the PEEK material by the additive method together with the technology of laser modification of the geometric structure of the material surface for applications in implant prosthetic treatment of patients is innovative and has not been used so far.

13

Visual Testing of Castings Defects after Vibratory Machining

Bańkowski D., Młynarczyk P.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 4

72--76

EN

The paper presents an example of the application of vibratory machining for castings based on the results of visual testing. The purpose of the work is to popularize non-destructive testing and vibratory machining as finishing process, especially in the case of cast objects. Visual testing is one of the obligatory non-destructive tests used for castings and welded joints. The basic requirements concerning the dimensional accuracy and surface texture of cast components are not met if visible surface flaws are detected. The tested castings, which had characteristic traces of the casting process, were subjected to vibratory machining. The machining with loose abrasive media in vibrating containers is aimed at smoothing the surface and reducing or completely removing flashes. To complement the visual testing were also conducted research on the contact profilometer Taylor Hobson PGI 1200. Particular attention was focused on measuring the height of flashes and changes in the surface of smoothed details based on BNIF No. 359 touch-visual patterns. Based on the work, it can be concluded that vibratory machining allows for removal flashes and smoothing of the surface of aluminum alloy cast objects.

14

Wpływ tworzyw sztucznych z odpadów przemysłowych poddanych obróbce powierzchniowej na właściwości mechaniczne kompozytu cementowego

Ghilan Dheya M. A., Teomete Egemen

Cement Wapno Beton

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2019

|

R. 24/86, nr 1

21--32

PL

W pracy omówiono wyniki badań możliwości wykorzystania odpadów z polipropylenu (PP), polietylenu (PE) i poliamidu (PA), uzyskanych z zakładu przetwarzania odpadów, jako wzmocnienie zapraw. Jednym z głównych problemów związanych z wykorzystywaniem odpadów z tworzyw sztucznych w kompozytach cementowych jest hydrofobowość powierzchni tworzywa sztucznego, która uniemożliwia adhezję zaczynu cementowego. W badaniach zastosowano rozcieńczony roztwór izopropanolu do obróbki powierzchniowej tworzyw sztucznych. Przy projektowaniu mieszanin uwzględniono trzy zmienne; rodzaj tworzywa sztucznego (PP, PE, PA), ich dodatek oraz ich obróbkę powierzchniową. Przeprowadzono badania wytrzymałości na zginanie i ściskanie. 1,5% dodatek PP i PE zwiększył wytrzymałość na zginanie zaprawy, natomiast obróbka powierzchniowa nie wpłynęła na tę wytrzymałość. Wraz ze zwiększaniem dodatku tworzyw sztucznych zwiększała się energia pękania zapraw z tymi tworzywami. Dla stosunku objętościowego 1,5% zwiększeniu uległa energia pękania w odniesieniu do mieszaniny wzorcowej, przy czym największy wpływ miał odpad PP. W przypadku niepoddanych obróbce powierzchniowej odpadów stwierdzono znaczne zwiększenie energii pękania, przy równoczesnym zmniejszeniu wytrzymałości na ściskanie i energii pękania przy ściskaniu, jednak ten wpływ uległ zwiększeniu po obróbce powierzchniowej odpadów. Odpadowe tworzywa sztuczne mogą być stosowane w zaprawach lub w betonach, w celu poprawy ciągliwości i udarności. Równocześnie wykorzystanie tych odpadów eliminuje zanieczyszczenie środowiska.

EN

This study aims to investigate the feasibility of using industrial waste plastics, polypropylene (PP), polyethylene (PE) and polyamide (PA), obtained from recycling factory, as reinforcement for mortar. As one of the main problems of using waste plastics in cementitious composites is the hydrophobic properties of the surface of the plastics, because it prevents the formation of adequate interfacial adhesion with cement paste. Surface treatment of waste plastics was applied using diluted solution of isopropanol. Three parameters were considered when designing the mortar mixtures; type of waste plastic (PP, PE, PA), their addition ratio and surface treatment. Bending and compression tests were conducted. 1.5% volume addition of PP and PE to mortars the flexural strength was increased, however, surface treatment of waste plastics did not affected this strength. As the waste plastic volume ratio increased, the flexural toughness of mortars reinforced with PP, PE and PA plastics was also increased. For the 1.5% volume ratio, there was the increase of flexural toughness with respect to the reference mortar and the highest influence had the PP. For the untreated waste plastics, there was significant increase in flexural toughness, while reduction in the compressive strength and compressive toughness was found, however, this surface treatment enhanced the compressive strength and compressive toughness with respect to untreated plastics. Waste plastics can be used for mortars and concretes reinforcement to improve the ductility and energy absorption capacity while eliminating pollution and regaining them in the economy as a structural material.

15

The application of advanced surface preparation methods in the adhesive bonding process

Rams Beata, Bugalski Tadeusz

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2019

|

Vol. 63, No. 5

45--55

EN

An important part in the process of adhesive bonding is played by the appropriate preparation of surfaces to be subjected to adhesive bonding. The objective of the tests discussed in the article was to identify the effect of various surface preparation methods, including cleaning, grinding, atmospheric plasma treatment and the ATOP method on the strength of adhesive-bonded joints. The tests involved the use of specimens made of aluminium alloy EN AW 5754 as well as specimens made of glass fibre-reinforced epoxy-based plastics. The specimens were subjected to overlap adhesive bonding involving the use of Araldite two-component epoxy adhesive (Huntsman). The article presents results of the static shear test (of the overlap joints) in relation to a given surface preparation method applied before the adhesive bonding process. The highest strength of the adhesive-bonded joints made in the aluminium alloy was obtained in relation to the ATOP method-based treatment. In addition, the above-named method makes it possible to properly prepare a cleaned surface by forming a protective layer ensuring proper surface preparation for several months. In turn, the highest strength of the adhesive-bonded joints made of glass fibre-reinforced plastics was obtained in relation to the surface treatment performed using atmospheric plasma.

PL

W procesie klejenia ważną rolę odgrywa odpowiednie przygotowanie powierzchni klejonych. Celem badań, przedstawionych w artykule, było sprawdzenie wpływu różnych metod przygotowania powierzchni, takich jak: oczyszczanie, szlifowanie, obróbka plazmą atmosferyczną, metoda ATOP na wytrzymałość złączy klejowych. Badania wykonano na próbkach ze stopu aluminium EN AW 5754 oraz próbkach z tworzyw sztucznych wykonanych na osnowie epoksydowej wzmacnianych włóknem szklanym. Próbki klejono na zakładkę klejem epoksydowym dwuskładnikowym - Araldite, firmy Huntsman. Przedstawiono wyniki badań statycznej próby ścinania złączy zakładkowych w zależności od zastosowanej metody przygotowania powierzchni przed klejeniem. Najwyższą wytrzymałości złączy klejowych, dla próbek wykonanych ze stopu aluminium, uzyskano przy obróbce metodą ATOP. Metoda ta pozwala także na odpowiednie zabezpieczenie oczyszczonej powierzchni poprzez wytworzenie warstwy ochronnej, zapewniając prawidłowe przygotowanie powierzchni przez okres kilku miesięcy. Natomiast przy łączeniu tworzyw sztucznych wzmacnianych włóknem szklanym najwyższą wytrzymałość uzyskano przy obróbce powierzchni przed procesem klejenia za pomocą plazmy atmosferycznej.

16

Analysis and Verification of Physical Properties of an AISI 4140 Steel by Vickers Indentation Analysis According to the Presence of Residual Stresses

Jung Changho, Lee Moon G., Jeon Yongho

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 3

823--827

EN

Residual stress has a great influence on the metal, but it is difficult to measure at small area using a general method. Residual stress calculations using the Vickers indentation can solve this problem. In this paper, a numerical simulation has been made for the residual stress measurement method of metal material deformed by high-speed impact. Then, the stress-strain curve at the high-speed deformation was confirmed through actual experiments, and the residual stresses generated thereafter were calculated by the Vickers indenter method. A Vickers indentation analysis under the same conditions was performed at the position where a residual stress of about 169.39 MPa was generated. Experiments were carried out and high speed impact was applied to the specimen to generate residual stress. The obtained results indicate that it is possible to identify residual stresses in various metals with various shapes through Vickers indentation measurements, and to use them for process and quality control.

17

The Use of Abrasive Waterjet Cutting to Remove Flash from Castings

Bańkowski D., Spadło S.

Archives of Foundry Engineering

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2019

|

iss. 3

94--98

EN

This article proposes to use abrasive waterjet cutting (AWJ) for deflashing, deburring and similar finishing operations in casting. The basic requirements concerning the dimensional accuracy and surface texture of cast components are not met if visible surface flaws are detected. The experiments focused on the removal of external flash from elements made of EN-GJL-150 cast iron. The method employed for finishing was abrasive waterjet cutting. The tests were carried out using an APW 2010BB waterjet cutting machine. The form profiles before and after flash removal were determined with a Taylor Hobson PGI 1200 contact profiler. A Nikon AZ100 optical microscope was applied to observe and measure the changes in the flash height and width. The casting surface after finishing was smooth, without characteristic sharp, rough edges that occur in the cutting of objects with a considerable thickness. It should be emphasized that this method does not replace precise cutting operations. Yet, it can be successfully used to finish castings for which lower surface quality is required. An undoubted advantage of waterjet cutting is no effect of high temperature as is the case with plasma, laser or conventional cutting. This process is also easy to automate; one tool is needed to perform different finishing operations in order to obtain the desired dimensions, both internal and external.

18

The Influence of Abrasive Paste on the Effects of Vibratory Machining of Brass

Bańkowski D., Spadło S.

Archives of Foundry Engineering

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2019

|

iss. 4

5--10

EN

The article presents the results of research on the finishing of M63 Z4 brass by vibratory machining. Brass alloy was used for the research due to the common use of ammunition elements, cartridge case and good cold forming properties on the construction. Until now, the authors have not met with the results of research to determine the impact of abrasive pastes in container processing. It was found that the additive for container abrasive treatment of abrasive paste causes larger mass losses and faster surface smoothing effects. The treatment was carried out in two stages: in the first stage, the workpieces were deburred and then polished. Considerations were given to the impact of mass of workpieces, machining time and its type on mass loss and changes in the geometric structure of the surface. The surface roughness of machining samples was measured with the Talysurf CCI Lite optical profiler. The suggestions for future research may be to carry out tests using abrasive pastes with a larger granulation of abrasive grains, and to carry out tests for longer processing times and to determine the time after which the parameters of SGP change is unnoticeable.

19

Microscopic Analysis of Layers Containing Mg2Si and Mg17Al12 Phases Fabricated on AZ91 Through Thermochemical Treatment

Mola R., Cieślik M.

Archives of Foundry Engineering

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2019

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iss. 3

119--124

EN

The thermochemical treatment applied to improve the surface properties of AZ91 consisted in heating the material in contact with AlSi10Mg powder at 445 oC for 30 min. During heat treatment process the powder was held under pressure to facilitate the diffusion of the alloying elements to the substrate and, accordingly, the formation of a modified layer. Two pressures, 1 MPa and 5 MPa, were tested. The resultant layers, containing hard Mg2Si and Mg17Al12 phases, were examined using an optical microscope and a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer (EDS). The experimental data show that the layer microstructure was dependent on the pressure applied. A thicker, three-zone layer (about 200 μm) was obtained at 1 MPa. At the top, there were Mg2Si phase particles distributed over the Mg17Al12 intermetallic phase matrix. The next zone was a eutectic (Mg17Al12 and a solid solution of Al in Mg) with Mg2Si phase particles embedded in it. Finally, the area closest to the AZ91 substrate was a eutectic not including the Mg2Si phase particles. By contrast, the layer produced at a pressure of 5 MPa had lower thickness of approx. 150 μm and a two-zone structure. Mg2Si phase particles were present in both zones. In the upper zone, Mg2Si phase particles were regularly distributed over the Mg17Al12 intermetallic phase matrix. The lower zone, adjacent to the AZ91, was characterized by a higher volume fraction of Mg2Si phase particles distributed over the matrix composed mainly of Mg17Al12. The alloyed layers enriched with Al and Si had much higher hardness than the AZ91 substrate.

20

Wood fibreboard paraffin hydrophobization and the impact of this treatment on the board surface finishing quality

Kudela Josef

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2019

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No. 107

115--123

EN

Wood fibreboard paraffin hydrophobization and the impact of this treatment on the board surface finishing quality. The aim of this paper is to analyse the causes of surface treatment defects in commercially produced wood fibreboards (FB). The analysis of: the obtained (measured and calculated) thermodynamic characteristics and of the results of microscopic examinations demonstrated that the excessive FB hydrophobization with paraffin may cause the paraffin to release from the FB surface and to migrate into the first primer layer. For the sanded FBs, similar paraffin migration was also observed into the second primer layer. This entailed lowered drying rate for the coating materials applied on FB, lower adhesion of the coating materials to the substrate and also lower adhesion between the particular coating layers applied. At the same time, the occurring frequency of surface treatment defects increased.