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1

Influence of Different Polishing Methods on Surface Roughness and Microhardness of Dental Composites

Mierzejewska Żaneta A., Łukaszuk Kamila, Choromańska Magdalena, Zalewska Anna, Borys Jan, Antonowicz Bożena, Kulesza Ewa

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 1

268--279

EN

The surface roughness and microhardness of dental composites greatly affects the durability of restorations. To evaluate the effect of three different polishing systems (Sof-Lex, Enhance+PoGo, Kenda) on the surface roughness and microhardness of microhybrid (Herculite XRV, Filtek Z250 and Charisma Flow) and nanohybrid (Herculite XRV Ultra, Filtek Z550 and Charisma Bulk Flow) composites resin used for dental fillings. Six different composites were used in the study. From each material, 40 cylinder-shaped samples were made. All samples were polymerized and polished using three different methods. To evaluate surface roughness a confocal laser microscope was used, and microhardness was determined using a universal Vickers hardness tester.The data were analysed using the one-way ANOVA test at a significance level of 0.05 for both tests. The smoothest surfaces in all groups of composites were obtained for control samples. Also in all groups of composite samples no statistically significant differences were found between the Sof-Lex and Enhance+PoGo. The measurement of surface roughness obtained for the Kenda system showed significantly lower values than for the other two methods. The surfaces of the control samples showed statistically significantly lower microhardness values compared to all polishing systems for all six tested resin composites, additionally no statistically significant differences were found between all finishing and polishing methods. Regardless of the finishing and polishing method used, the lowest microhardness values among microhybrid materials were found for Charisma Flow, while among nanohybrid materials the lowest values were obtained for Herculite HRV Ultra. Finishing and polishing increases the microhardness of microhybrid and nanohybrid composite resin. The use of Kenda three step polishing system resulted in smoother surface for all tested composite materials compared to the Sof-Lex and Enhance+PoGo systems, while the finishing and polishing method had little effect on the microhardness of the surface.

2

Effect of Regular Shot Peening and Semi-Random Shot Peening Conditions on Selected Properties of the Surface Layer of Gray Cast Iron

Skoczylas Agnieszka, Zaleski Kazimierz

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 2

284--295

EN

Both dispersed and concentrated shot peening can be an effective method for the finishing of machine components. This work investigates the effect of two different shot peening (SP) processes conducted with the same technological parameters on selected properties of the surface layer of gray cast iron EN-GJL 250. Specifically, regular shot peening (RSP) and semi-random shot peening (SRSP) were investigated in the study. The results demonstrated that the surface quality of EN-GJL 250 samples was higher after RSP than after SRSP. The analyzed surface roughness parameters were lower after RSP than after SRSP, with the exception of the Rvk parameter. As a result of RSP, the analyzed roughness parameters increased from 5% to 62% in relation to their values after pre-treatment. The lowest values of the surface roughness parameters were obtained after RSP conduced with the impact energy E = 100 mJ, the distance between the dimples x = 0.3 mm, and the diameter of the shot peening element d = 14.3 mm. Assessment of the 3D surface topography showed significant differences in the formation of machining traces depending on the employed surface treatment. In RSP, the traces were arranged in a uniform manner, with the assumed step, whereas in SRSP the shot peening traces had no set pattern of orientation. The application of RSP and SRSP caused an increase in surface microhardness. The maximum surface microhardness was 75 HV0.5 for RSP and 98 HV0.5 for SRSP. Residual stresses were higher after SRSP than after RSP. Compressive residual stresses were induced in both types of shot peening process.

3

Effect of various factors on the measurement error of structural components of machine parts materials microhardness using computer vision methods

Vlasovets Vitaliy, Vlasenko Tatiana, Kovalyshyn Stepan, Kovalyshyn Olesy, Kovalyshyn Oleg, Kurpaska Sławomir, Kiełbasa Paweł, Bilovod Oleksandra, Shulga Lyudmila

Przegląd Elektrotechniczny

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2023

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R. 99, nr 1

323--329

EN

To assess the causes of failure of parts in operation, it is often necessary to assess the degradation of the structural and phase composition of the material and determine the cause of its change. Microhardness test is used to evaluate the mechanical properties of microvolumes of the material. Microhardness of structural components of steels and cast irons (armco iron ferrite, austenitic component of steel 12Х18Н10Т and cementite of centrifugally cast chrome-nickel cast iron (cast coating Ø910 mm)) was determined by restored four-sided pyramid impression with a square base and a top angle of 136±1. The paper evaluates the influence of the main factors on the micro-hardness error of ferritic, austenitic and carbide component of steels and cast irons: the amount and speed of the indenter load, the stiffness of the substrate, the field of distribution of plastic deformations around the impression, the quality of the surface preparation, the influence of grain boundaries and the relaxation of the impression shape over time. The main factors affecting the accuracy of measurements by the reconstructed impression method have been determined for each of the investigated phases: ferrite, austenite, and cementite.

PL

Aby ocenić przyczyny awarii części w eksploatacji, często konieczna jest ocena degradacji składu strukturalnego i fazowego materiału oraz określenie przyczyny jego zmiany. Do oceny właściwości mechanicznych mikroobjętości materiału stosuje się test mi-rotwardości. Mikrotwardość składników strukturalnych stali i żeliwa (ferryt żelaza armco, austenityczny składnik stali 12Х18Н10Т i cementyt odśrodkowo odlewanego żeliwa chromowo-niklowego (powłoka odlewu Ø910 mm)) określono przez przywrócony wycisk piramidy czterobocznej o podstawie kwadratowej i kącie wierzchołkowym 136±1. W pracy oceniono wpływ głównych czynników na błąd mikrotwardości ferrytycznego, austenitycznego i węglikowego składnika stali i żeliwa: wielkości i prędkości obciążenia wgłębnika, sztywności podłoża, pola rozkładu odkształceń plastycznych wokół wycisku, jakości przygotowania powierzchni, wpływu granic ziaren oraz relaksacji kształtu wycisku w czasie. Określono główne czynniki wpływające na dokładność pomiarów metodą zrekonstruowanego wycisku dla każdej z badanych faz: ferrytu, austenitu i cementytu.

4

Impact of orthodontic adhesive magnets on the mechanical properties and degree of conversion of a photopolymerized orthodontic adhesive

Al-Hayali Saud Khalil, Abed Mazin Ahmed, Al Qassar Sarmad Salih

Ochrona przed Korozją

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2023

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nr 10

329--334

EN

The purpose of this study was to calculate the effects of magnetic field (MF) on the degree of conversion (DC%) and mechanical properties of a photopolymerized orthodontic adhesive. In this investigation, Vega Ortho UV orthodontic adhesive was employed. The applied magnetic field had varying intensities (fixed at 0.01 T, 0.03 T, 0.05 T, 0.1 T, 0.15 T, and 0.2 T and a duration of 5 minutes) and a fixed frequency of 50 Hz. Vickers microhardness and DC% were investigated utilizing the specimens, which were created using circular molds and prepared for compression strength (CS) testing in accordance with ISO 4049. To evaluate DC% before and after MF exposure, Fourier-transform infrared spectroscopy (FTIR/ ATR) was performed. A microhardness tester was used to quantify the samples’ initial VHN while subjecting them to a 500 g load for 15 seconds. After that, properties were evaluated. With the aid of scanning electron microscopy (SEM), the surfaces were evaluated. The one-way analysis of difference and Tukey significant difference tests were used to evaluate the data. Analyses of statistical data showed that DC% tends to rise up to 0.05 T. When compared to the control, VHN and compression strength were considerably decreased after 0.03 T MF (p ≤ 0.05). However, there was a significant difference between the VHN and CS as their values increased with increasing magnetic field intensity. The surfaces of the Vega Ortho were deteriorated, as shown by SEM scans. It was found that the effect of the magnetic field caused changes in the physical and chemical properties.

PL

Celem badania było określenie wpływu pola magnetycznego (MF) na stopień konwersji (DC%) i właściwości mechaniczne fotopolimeryzowanego kleju ortodontycznego. W badaniu zastosowano klej ortodontyczny Vega Ortho UV. Zastosowane pole magnetyczne miało różne natężenia (0,01 T, 0,03 T, 0,05 T, 0,1 T, 0,15 T i 0,2 T przez 5 minut) i stałą częstotliwość 50 Hz. Mikrotwardość Vickersa i DC% ustalono z wykorzystaniem próbek, które zostały wykonane przy użyciu okrągłych form i przygotowane do badania wytrzymałości na ściskanie (CS) zgodnie z normą ISO 4049. Do oceny DC% przed ekspozycją na działanie pola magnetycznego i po niej wykorzystano spektroskopię w podczerwieni z transformacją Fouriera (FTIR/ATR). Do ilościowego określenia początkowej wartości VHN próbek użyto mikrotwardościomierza, poddając je obciążeniu 500 g przez 15 sekund. Następnie dokonano oceny właściwości. Ocenę powierzchni przeprowadzono za pomocą skaningowej mikroskopii elektronowej (SEM). Dane poddano jednokierunkowej analizie różnic i testowi istotnej różnicy Tukeya. Analizy danych statystycznych wykazały, że DC% ma tendencję do wzrostu do poziomu 0,05 T. W porównaniu z próbką kontrolną wartości VHN i wytrzymałości na ściskanie uległy znacznemu zmniejszeniu po oddziaływaniu 0,03 T MF (p ≤ 0,05). Istniała jednak znacząca różnica między VHN i CS, ponieważ ich wartości rosły wraz ze wzrostem natężenia pola magnetycznego. Powierzchnie Vega Ortho uległy degradacji, jak wykazały skany SEM. Stwierdzono, że wpływ pola magnetycznego spowodował zmiany właściwości fizykochemicznych.

5

Effects of thermo-chemical treatment and grinding process of external cylindrical surfaces on residual stresses in 13CrMo4-5 steel

Wójcik R., Sawicki J.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 120, nr 1

10--21

EN

Purpose This paper presents a study aimed at determining the effect of the carburizing treatment process and the subsequent grinding process on the residual stresses occurring in ring-shaped specimens made of 13CrMo4-5 steel. Design/methodology/approach During the tests, vacuum carburizing was used, achieving an effective case depth ECD = 0.5 mm. Subsequently, the cylindrical outer surfaces of the samples were ground by conventional plunge grinding and with innovative kinematics using a test stand based on a conventional flat-surface grinding machine. As part of the study, microhardness and residual stresses were measured before and after grinding. Measurements were carried out to a depth of 1 mm. The main component of the stand is an original special device that allows the cylindrical specimen to be clamped. Then the angle between its axis of rotation and the axis of rotation of the grinding wheel is set with respect to the plane of the grinding machine’s magnetic table. In the described tests, the axis of rotation of the cylindrical specimen was deviated from its original position by 15° and set at an angle of 75° to the axis of rotation of the grinding wheel. The specimens were ground with a grinding wheel of noble electro-corundum marked 38A60K8V. In both kinematic cases of the grinding process, a machining allowance of 0.01 mm was removed. Findings Grinding using innovative kinematics did not cause any significant changes in the microhardness distribution, either for vacuum or conventional carburizing. In addition, residual stress measurements using the Dawidenkov-Sachs method showed that innovative grinding enables a more favourable distribution than those obtained after conventional plunge grinding. Research limitations/implications Further research will focus on, among others, selecting the angular settings of the workpiece axes relative to the grinding wheel axes depending on their dimensions. Grinding guidelines should include coverage ratio, infeed value, grinding time, and peripheral speeds. In addition, the plan for future research includes measuring the components of the grinding force and the geometric structure of the surface. Practical implications Grinding process is a crucial stage of steel treatment in almost every industrial branch. In sustainable manufacturing, it is extremely important to produce high-quality items while reducing the cost of manufacturing and taking care of the environment and workers’ health. Originality/value The proposed test stand, together with the authors’ device, makes it possible to conduct machining of the external surfaces of cylindrical workpieces on a flat surface grinder. In this case, the innovation of the grinding process consists of the non-parallel alignment of the cylindrical rotational axis of the specimen and the rotational axis of the grinding wheel with respect to the plane of the magnetic grinding table.

6

Wpływ parametrów wytwarzania na mikrostrukturę i właściwości spiekanych kół zębatych wykonanych na bazie proszku Distaloy AQ

Sułowski Maciej, Dąbrowski Robert, Żarów Martyna

Inżynieria Materiałowa

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2023

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Vol. 44, nr 1

6--11

PL

Zbadano wpływu parametrów wytwarzania, tzn. infiltracji miedzią, na mikrostrukturę i właściwości mechaniczne kół zębatych wytworzonych techniką metalurgii proszków na bazie proszku żelaza Distaloy AQ. Zakres badań obejmował określenie zmiany wymiarów kół oraz ich gęstości, przed i po procesie infiltracji, pomiar wytrzymałości na statyczne zginanie zębów, pomiar mikrotwardości kół zębatych oraz analizę ich mikrostruktury. Koła zębate podzielono na cztery grupy; jedna z nich nie była infiltrowana miedzią, pozostałe trzy infiltrowano kolejno jednym (1,4% Cu), dwoma (2,8% Cu) i trzema (4,2% Cu) miedzianymi pierścieniami. Stwierdzono, że infiltracja miedzią powoduje wzrost wytrzymałości na zginanie badanych spieków, lecz tylko w przypadku zawartości 1,4% Cu. Większa ilość miedzi powoduje obniżenie wytrzymałości na zginanie zębów kół. Badania wykazały również, że infiltracja miedzią nie wpływa korzystnie na mikrotwardość kół zębatych.

EN

The influence of production parameters i.e., copper infiltration, on the microstructure and mechanical properties of gear wheels initially manufactured by powder metallurgy was investigated. Distaloy AQ iron powder was used for production these gears. The scope of research included the determination of changes in the dimensions of the gear wheels and their density, before and after the infiltration process, measurement of the strength to static bending, measurement of the microhardness of the gear wheels and analysis of their microstructure. The gear wheels are divided into four groups; one of them was not infiltrated with copper, the remaining three were infiltrated successively with one (1.4% Cu), two (2.8% Cu) and three (4.2% Cu) copper rings. It was found that copper infiltration increases the bending strength of the tested sinters, but only in the case of 1.4% Cu content. The greater amount of copper reduces the bending strength of the gear wheels. Research has also shown that copper infiltration does not have a positive effect on the microhardness of gear wheels.

7

Analytical versus experimental investigation of physical and mechanical characteristics of stir cast hybrid aluminium nanocomposite

Kumar Dinesh, Singh Satnam, Angra Surjit

Composites Theory and Practice

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2023

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R. 23, nr 3

136--144

EN

Aluminium alloys have good mechanical and physical properties and are lightweight, easy to cast, and simple to machine. Aluminium alloys are widely used in the aviation industry, auto sector, defence sector, and structural industries because of their promising abilities. The fundamental aim of this study was to investigate the mechanical properties and physical characteristics of a stir cast hybrid aluminium nanocomposite reinforced with 1-3 wt.% cerium oxide (CeO2) and graphene nanoplatelets (GNPs). Utilizing SEM, microstructural analysis was carried out. The existence of the elements of the reinforcement in the manufactured nanocomposite specimens was verified using EDAX. With an increase in the reinforcement wt.%, improvements in the mechanical and physical properties were seen. In the hybrid nanocomposites reinforced with 3 wt.% GNPs and 3 wt.% CeO2, a low porosity of 1.06% was observed. The best results for tensile strength, yield strength, and microhardness were 398 MPa, 247 MPa, and 119.6 HV, respectively. The SEM micrographs of the studied materials showed that the reinforcement particles were uniformly dispersed and refined into ultrafine grains.

8

TIG Welding of Ti6Al4V: Effect of Ti6Al4V ELI as Filler Metal

Omoniyi Peter O., Mahamood Rasheedat. M., Adeleke Adekunle A., Ikubanni Peter P., Akinlabi Stephen A., Akinlabi Esther Titilayo

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

769--773

EN

Titanium and its alloys have significant uses in the biomedical, chemical, and aerospace industries. In this article, the current and gas flow rates were varied using Taguchi’s experiment design. The mechanical properties of the welded joint made using tungsten inert gas (TIG) welding and Ti6Al4V ELI as filler metal was characterized using the microstructure, microhardness, and tensile strength. The joint was classified into three regions, namely, fusion zone (FZ), heat affected zone (HAZ), and base metal (BM). Results show martensitic microstructure within the fusion zone (FZ) and the heat affected zone (HAZ), which resulted in an increased hardness within the fusion and heat affected zone.

9

Microstructure and Selected Mechanical Properties of Cr25Zr25Co20Mo15Si10Y5 and Cr25Co25Zr20Mo15Si10Y5 Multicomponent Alloys

Glowka Karsten, Zubko Maciej, Piotrowski Krzysztof, Świec Paweł, Prusik Krystian, Albrecht Robert, Stróż Danuta

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 3

1143--1149

EN

In the presented work, two multicomponent Cr25Zr25Co20Mo15Si10Y5 and Cr25Co25Zr20Mo15Si10Y5 alloys were produced from bulk chemical elements using the vacuum arc melting technique. X-ray diffraction phase analysis was used to determine the phase composition of the obtained materials. Microstructure analysis included scanning electron microscopy and energy dispersive X-ray spectroscopy techniques. The studies revealed the presence of multi-phase structures in both alloys. Elemental distribution maps confirmed the presence of all six alloying elements in the microstructure. The segregation of chemical elements was also observed. Microhardness measurement revealed that both alloys exhibited microhardness from 832(27) to 933(22) HV1.

10

Gas Nitriding of the Near-Beta-Titanium Alloy

Luk’yanenko Alexander G., Pohrelyuk Iryna M., Fedirko Viktor M., Molyar A. G., Trush Vasyl, Kravchyshyn T. M.

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 2

431--438

EN

The present research investigates the nitriding kinetics of the near-beta-titanium alloy of Ti-Al-Nb-Fe-Zr-Mo-V system at 750, 800, and 850°C in gaseous nitrogen at 105 Pa for 2, 4, and 8 h. The parabolic coefficient kp of the layer’s growth rate and the nitriding activation energy E are set as the kinetic parameters of the nitrided layer’s growth. The activation energy for the formation of a nitride layer is ~108 kJ/mol. The authors discuss the morphology of the nitride layers as well as their roughness and surface hardness. The study determines the effective diffusion coefficient for the growth of diffusion layers in the temperature range of 750...850°C: Def = D0 × exp (-E/RT), where D0 = 0.0177 m2/s; E = 215.7 kJ/mol. The friction coefficient of the disk from nearbeta-titanium alloy with a bronze block is lowered by significantly more than 10 times after gas nitriding, and the temperature in the friction zone is reduced by 2.5 times.

11

Effect of Ball on SPS Characteristics of Ti-Al-Nd Powders Prepared by High Energy Ball Milling

Lee Hyunseung, Rhee Hoseong, Lee Sangsoo, Chang Si Young

Archives of Metallurgy and Materials

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2023

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Vol. 68, iss. 1

81--84

EN

The effects of different types of balls on spark plasma sintering (SPS) characteristics of high energy ball milled Ti-48wt% Al-4wt% Nd powders were investigated. After ball milling with STS balls and zirconia balls at 800 rpm for 3 h in argon atmosphere, both powders showed shape factors of about 0.8, but their average powder sizes differed respectively at approximately 11 µm and 5 µm. From XRD results, only the peaks of pure Ti, Al and Nd were detected in both powders. The obtained Ti-Al-Nd powders were consolidated by SPS technique at 1373 K for 15 min under a pressure of 50 MPa in vacuum, resulting in high density over 99%. EDS and XRD analyses indicated the formation of binary phases such as TiAl3, TiAl, Ti3Al5, and NdAl3 after SPS in both cases of STS and zirconia balls, while the ternary Ti-Al-Nd phase was detected only in the case of zirconia balls. The size of second phases was slightly smaller in the case of zirconia balls. The microhardness of the sample was 790 Hv with zirconia balls and 540 Hv with STS balls.

12

An in vitro examination of fluoride ions release from selected materials – resin-modified glass-ionomer cement (Vitremer) and nanohybrid composite material (Tetric EvoCeram)

Kosior Piotr, Klimas Sylwia, Nikodem Anna, Wolicka Justyna, Diakowska Dorota, Watras Adam, Wiglusz Rafał J., Dobrzyński Maciej

Acta of Bioengineering and Biomechanics

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2023

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Vol. 25, no. 1

101--115

EN

The aim of this study was to examine a short-term fluoride ions release from selected materials – resin-modified glass ionomer –Vitremer (3M ESPE) and nanohybrid universal composite – Tetric EvoCeram (IvoclarVivadent). Release of fluoride ions [µg/mm2 /h] from Tetric EvoCeram and Vitremer into nine environments (artificial saliva – AS, deionized water and 0.9% NaCl) differing in composition of the solution and pH was determined. Six samples were prepared for each solution. In the short-term study, the measurements were taken after 1, 3, 24, 48, 72 and 168 hours. The cumulative values as well as levels of fluoride ions released at concrete time intervals were compared. Within 7 days (168 hours), both materials showed variable levels of fluoride ions release. The highest value of fluoride ions release from nanohybrid Tetric EvoCeram material was reported in deionized water (8) after 24 hours (1.550 ± 0.014 [µg/mm2 /h]) and the lowest value was read in the artificial saliva AS pH 7.5 (5) after 1 hour (0.022 ± 0.001 [µg/mm2 /h]). What’s more, the highest value of Frelease from Vitremer was found in deionized water (8) after 168 hours of immersion (24.021 ± 2.280 [µg/mm2 /h]) and the lowest value was in the artificial saliva AS (without Ca2+) pH 4.5 (6) (0.303 ± 0.249 [µg/mm2 /h]) after 168 hours. Cumulated release of F– after 7 days was notably higher from resin- modified glass ionomer material – Vitremer in all artificial saliva solutions (1–7) which imitated the environment of oral cavity. Therefore, we can assume that Vitremer has better remineralization potential and it may constitute a more effective method of tooth decay prevention.

13

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.

14

Influence of heat treatment on the properties of explosively welded Cu-Al joint

Lokaj Jan, Sahul Miroslav, Sahul Martin, Čaplovič Ľubomír

Materiały Wysokoenergetyczne

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2022

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T. 14

4--13

EN

Explosive welding of copper C10200 to aluminium alloy AW 5083 was performed. C10200 was proposed as a flyer plate due to its suitable plastic properties. A parallel layout of welded metals was selected to attain a more stable welding process. Welding parameters and conditions were determined. The surfaces of both materials were mechanically machined and degreased prior to welding which was performed using Semtex S30. The bimetals were characterized by a regular wavy interface. The aim of the research was to establish the influence of heat treatment on both the structure and microhardness at the interface of the explosively welded bimetal Al-Cu. Heat treatment was performed at 250, 300 and 350 °C over 2, 3 and 4 h. After heat treatment, an increase in Inter Metallic Compounds (IMC) was observed, proportional to the increasing temperature. An analysis of chemical composition carried out by EPMA (Electron Probe Micro Analysis) confirmed the presence of Inter Metallic Phases (IMP) such as θ (Al2Cu), η2 (Al2Cu), ξ2 (Al3Cu4), δ (Al2Cu3), γ1 (A14Cu9). The microhardness decreased after the heat treatment in the bimetal but significantly increased at the interface as a consequence of IMC formation.

PL

Wykonano zgrzewanie wybuchowe stopu aluminium miedź C10200 i AW 5083. C10200 został zaproponowany jako płyta napędzana ze względu na jego odpowiednie właściwości plastyczne. Wybrano równoległy układ zgrzewanych metali, aby uzyskać bardziej stabilny proces łączenia. Określono parametry i warunki łączenia. Powierzchnie obu materiałów zostały poddane obróbce mechanicznej i odtłuszczeniu przed zgrzewaniem wykonanym przy użyciu Semtex S30. Bimetale charakteryzowały się regularną falistą powierzchnią styku. Celem badań było określenie wpływu obróbki cieplnej zarówno na strukturę, jak i mikrotwardość na granicy faz bimetalu Al-Cu zgrzewanego wybuchowo. Obróbkę cieplną przeprowadzono w 250, 300 i 350 °C przez 2, 3 i 4 godziny. Po obróbce cieplnej zaobserwowano wzrost związków międzymetalicznych (IMC), który był proporcjonalny do wzrostu temperatury. Analiza składu chemicznego przeprowadzona przez EPMA (Electron Probe Micro Analysis) potwierdziła obecność IMP takich jak θ (Al2Cu), η2 (AlCu), ξ2 (Al3Cu4), δ (Al2Cu3), γ1 (Al4Cu9). Mikrotwardość zmniejszyła się po obróbce cieplnej w bimetalu, ale znacznie wzrosła na granicy faz w wyniku tworzenia IMC.

15

Hardfacing of mild steel with wear-resistant Ni-based powders containing tungsten carbide particles using powder plasma transferred arc welding technology

Appiah Augustine Nana Sekyi, Bialas Oktawian, Żuk Marcin, Czupryński Artur, Konadu Sasu David, Adamiak Marcin

Materials Science Poland

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2022

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Vol. 40, No. 3

42--63

EN

This study explores the use of powder plasma transferred arc welding (PPTAW) as a surface layer deposition technology to form hardfaced coatings to improve upon the wear resistance of mild steel. Hardfaced layers were prepared using the PPTAW process with two different wear-resistant powders: PG 6503 (NiSiB + 60% WC) and PE 8214 (NiCrSiB + 45% WC). By varying the PPTAW process parameters of plasma gas flow rate (PGFR) and plasma arc current, hardfaced layers were prepared. Microscopic examinations, penetration tests, hardness tests, and abrasive wear resistance tests were carried out on the prepared samples. Hardfacings prepared with PG 6503 had a hardness of 46.3–48.3 HRC, while those prepared with PE 8214 had a hardness of 52.7–58.3 HRC. The microhardness of the matrix material was in the range of 573.3–893.0 HV, while that of the carbides was in the range of 2128.7–2436.3 HV. The abrasive wear resistance of the mild steel was improved after deposition of hardfaced layers by up to 5.7 times that of abrasion-resistant heat-treated steel, Hardox 400, having a nominal hardness of approximately 400 HV. The hardness and wear resistance were increased upon addition of Cr as an alloying element. Increasing the PGFR increased the hardness and wear resistance of the hardfacings, as well as increasing the number of surface cracks. Increasing the plasma transferred arc (PTA) current resulted in hardfacings with fewer cracks but lowered the wear resistance.

16

Parametric optimisation of microhardness on heat-treated electroless Ni-YSZ cermet coating

Bahiyah Baba N., Ghazali A. S., Abdul Rahman A. H., Sharif S

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 112, nr 1

33--41

EN

Purpose: The paper discusses the parametric optimisation of the electroless Ni-YSZ cermet coating microhardness upon heat treatment. Heat treatment is a process to increase the mechanical properties of the electroless nickel coating and it can be enhanced by manipulating its parameters. Parametric optimisation is conducted by the design of experiment full factorial 3x3 with 27 runs. Treating temperature, treating time and ceramic particle size parameters at 3-level are evaluated using statistical tool ANOVA in Minitab20. Design/methodology/approach: Ni-YSZ cermet coating is deposited onto a high-speed steel substrate using the electroless nickel co-deposition method. The temperature and time were varied in a range of 300-400°C and 0-2 hours respectively. The microhardness measurements were carried out using a Vickers microhardness tester (Shimadzu) according to ISO 6507-4. The surface characterisation was analysed using Cambridge Stereoscan 90 Scanning Electron Microscope (SEM) coupled with Energy Dispersive X-ray Analysis (EDXA). Findings: The optimum condition in obtaining high microhardness on Ni-YSZ cermet coating is evaluated by statistical tool ANOVA in Minitab20 software. It is found that the most significant parameter for high microhardness is at the treating temperature of 400°C followed by treating time at 2 hours using nano-sized YSZ particles. The ceramic particle size is found not a significant parameter in obtaining a high microhardness, however it has effect on interaction between treating temperature and treating time. Research limitations/implications: The paper only limits to the optimisation condition of microhardness on Ni-YSZ cermet coating hardness property by varying heat treatment parameters. Practical implications: The optimisation condition obtained might only applicable to the electroless Ni-YSZ cermet coating with similar electroless nickel solution and treatments. Originality/value: The value of this work is the heat treatment parametric optimisation to obtain high microhardness on electroless Ni-YSZ cermet coating by using the design of experiment 3-level full factorial.

17

Effect of heat treatment on microhardness of electroless Ni-YSZ cermet coating

Bahiyah Baba N., Ghazali A. S., Abdul Rahman A. H., Sharif S.

Journal of Achievements in Materials and Manufacturing Engineering

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2022

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Vol. 113, nr 1

5--12

EN

Purpose: The paper discussed the effect of heat treatment on electroless nickel-yttria-stabilised zirconia (Ni-YSZ) cermet coating. Ni-YSZ cermet coating has potential applications such as cutting tools, thermal barriers, solid oxide fuel anode, and various others. The compatibility of ceramic YSZ and metallic nickel in terms of the mechanical properties such as hardness by varying the heating temperature, time and ceramic particle size is highlighted. Design/methodology/approach: Ni-YSZ cermet coating was deposited onto a highspeed steel substrate using the electroless nickel co-deposition method. The temperature and time were varied in a range of 300-400°C and 1-2 hours, respectively. The microhardness measurements were carried out using a Vickers microhardness tester (Shimadzu) according to ISO 6507-4. The surface characterisation of the cermet coating was carried out using JOEL Scanning Electron Microscope (SEM) coupled with Energy Dispersive X-ray (EDX) JSM 7800F. The crystallographic structure of materials was analysed by X-ray diffraction (XRD) Bruker D8 Advance instrument. Findings: It was found that the microhardness of Ni-YSZ cermet coating with the ratio of 70:30, respectively, is directly proportional to the heating temperature and time. Heating the Ni-YSZ cermet coating at 300°C from room temperature (rtp) to 1 hour shows a 12% microhardness increment, while from 1 to 2 hours gives a 19% increment. Compared to heating at 350°C and 400°C, the increment is more significant at 33% and 49% for rtp to 1 hour and 8% and 16% for 1 to 2 hours, respectively. In addition, the effect of varying YSZ particle size in the Ni-YSZ cermet gave response differently for heating temperature and heating time. Research limitations/implications: The paper is only limited to the discussion of the heat treatment effect on Ni-YSZ cermet coating hardness property. The tribological effect will be in future work. Practical implications: The microhardness data may vary due to the Vickers microhardness force applied and the amount of ceramic particle incorporation and phosphorus content in the nickel matrix. Originality/value: The value of this work is the compatibility of the ceramic YSZ and metallic nickel matrix in terms of mechanical properties, such as hardness, upon heat treatment.

18

Tribological properties of the FeNi alloys electrodeposited with and without external magnetic field assistance

Białostocka Anna Maria, Klekotka Marcin, Klekotka Urszula, Kalska-Szostko Beata

Eksploatacja i Niezawodność

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2022

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Vol. 24, no. 4

687--694

EN

The hereby work presents the tribological properties of the iron-nickel alloys and their dependence on the microstructure and thickness of the probes as well as the presence of an external magnetic field during the synthesis. Coatings were electroplated on the brass and copper metallic substrates using galvanostatic deposition in the same electrochemical bath condition (Fe and Ni sulfates) and the electric current density. The surface morphology of the films was observed by Scanning Electron Microscopy. The average composition of all FeNi coatings was measured using Energy Dispersive X-ray Spectroscopy. Tribo-mechanical properties such as microhardness, roughness, and friction coefficient were determined in the obtained structures. The morphology and tribologial properties of the FeNi coatings clearly depend on both the substrate (Cu, CuZn) itself and the presence of an external magnetic field (EMF) applied during the deposition process.

19

The influence of workpiece speed on microhardness and residual stresses in vacuum-carburised 20MnCr5 steel using the single-piece flow method

Sawicki J., Januszewicz B., Sikora M., Witkowski B.

Archives of Materials Science and Engineering

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2022

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Vol. 115, nr 2

66--75

EN

Purpose: To determine the impact of selected conditions of abrasive treatment on the value and distribution of microhardness and residual stresses in layers carburised by a continuous single-piece flow method. Design/methodology/approach: Reference pieces were low pressure carburised at 920°C and then heat-treated in a 4D Quench heat treatment chamber at a pressure of 7 bar and tempered at 190ºC for 3 hours. In the next stage, samples were ground at various vw piece speeds, introducing grinding fluid into the cutting zone using the WET spraying method or using the MQL method at a minimum flow rate. The distribution of microhardness and residual stresses generated in the technological outer layer of the pieces following heat and chemical treatment and the grinding process was measured. Findings: Results of the tests indicated that the vw piece speed and method used to supply cooling and lubricating fluid to the grinding zone had an impact on selected parameters of the technological outer layer of flat samples made of 20MnCr5 steel. The process of grinding using an electrocorundum grinding wheel results in a deterioration of residual stresses in the material. For each of the three analysed vw piece speeds, reduced changes in material microhardness prior to cutting occur in the outer layer of samples ground using GF supplied at a minimum flow rate using the MQL method. Research limitations/implications: Environmental considerations and having to conform to increasingly stringent regulations related to environmental protection and employee safety motivate researchers and businesses to entirely eliminate or reduce the use of grinding fluids in the grinding process and, therefore, to optimise grinding technology. Practical implications: Modern manufacturing industry requires the grinding process, which follows heat and chemical treatment, to be performed with the highest possible efficiency. However, retaining high parameters of the technological outer layer in comparison to the sample material following vacuum carburisation (before grinding) is extremely difficult. An optimised configuration of parameters of the grinding process and method of supplying grinding fluids enables meeting the current and future high expectations of the industry in this regard. Originality/value: The tests have enabled us to determine the impact of the applied vw workpiece speed and method of supplying grinding fluid on microhardness and residual stresses. Generally speaking, grinding with an electrocorundum grinding wheel results in a deterioration of residual stresses. For both methods of supplying GF (WET and MQL), the distribution of microhardness in the material of the samples ground with the highest workpiece speed (18.0 m/min) indicated no significant differences with regard to the distribution of microhardness in the material of the samples following heat and chemical treatment.

20

Vibratory Shot Peening of Elements Cut with Abrasive Water Jet

Skoczylas Agnieszka

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 2

39--49

EN

The paper presents the effect of technological parameters of vibratory shot peening on the roughness and microhardness of the surface layer of shot peened objects. Moreover, the surface topography results from vibratory shot peening was analyzed. In the experiment, samples made of 1.4301 stainless steel were used, which were cut by abrasive water jet (AWJ). The geometrical structure of the surface after vibratory shot peening was changed. The surface roughness was obtained in the range of Rsk = -0.600 ÷ -1.115 and Sa = 3.01 ÷ 6.53 μm, The value of microhardness ΔHV, near to the surface, is from 36 HV0.05 to 100 HV0.05. The changes in microhardness reach on the depth gh = 100 μm. An analysis of variance ANOVA for the investigated dependent variables was performed. The Tukey's test was used to checked the influence of the independent variable on the dependent variable. The aim to obtain favorable properties of the surface layer of elements after abrasive water jet cutting, it is recommended to use a vibratory shot peening time of approx. 6 minutes and balls of diameter d = 6 mm.