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1

Analysis of the Microstructure And Mechanical Properties of Duplex Steel Joints

Witkowska Małgorzata, Kowalska Joanna, Chronowska-Przywara Kinga

Tribologia

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2024

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nr 1

147--158

EN

The article presents a study, the aim of which was to analyze the microstructure and mechanical properties of welded joints of austenitic-ferritic duplex steel X2CrMnNiN21-5-1. This steel is characterized by good resistance to various types of corrosion, good strength properties and good weldability. Due to all these advantages, it is used in many industry sectors, and the main joining techniques are welding technologies. In this study, two joining techniques were used, SMAW (Shielded Metal Arc Welding) and GTA (Gas Tungsten Arc). The obtained welded joints were subjected to: macroscopic and microscopic metallographic tests, mechanical tests (static bending test and microhardness measurements), diffraction tests, and wear resistance tests. The results showed that the microhardness of the welds is similar and does not depend on the welding method used. In the microstructure of the analyzed joints there are two phases: austenite (γ) and ferrite (δ), with different morphologies depending on the welding conditions, which affect the phase transformations. Material wear within the weld is greater than in the base material.

PL

Celem badań była analiza mikrostruktury i własności mechanicznych złączy spawanych stali austenityczno-ferrytycznej typu duplex X2CrMnNiN21-5-1. Stal ta charakteryzuje się dobrą odpornością na różnego rodzaju korozje, dobrymi własnościami wytrzymałościowymi i dobrą spawalnością. Dzięki tym wszystkim zaletom znajduje zastosowanie w wielu gałęziach przemysłu, a głównymi technikami jej łączenia są technologie spawalnicze. W pracy zastosowano dwie techniki łączenia metodą SMAW (Shielded Metal Arc Welding) i GTA (Gas Tungsten Arc). Uzyskane złącza spawane poddano: badaniom metalograficznym makro- i mikroskopowym, badaniom mechanicznym (statyczna próba zginania i pomiary mikrotwardości), badaniom dyfrakcyjnym oraz badaniom odporności na zużycie. Wyniki badań pokazały, że mikrotwardości spoin są zbliżone i nie zależą od zastosowanej metody spawania. W mikrostrukturze analizowanych złącz występują dwie fazy austenit (γ) i ferryt (δ) o zróżnicowanej morfologii zależnej od warunków spawania, które wpływają na przemiany fazowe. Zużycie materiału w obrębie spoiny jest większe aniżeli w materiale rodzimym.

2

Microstructural study of the composite nickel based, containing different Al amounts, sintered by an unconventional technique and forged

Bendriss Houceme, Boudebane Said, Lemboub Samia, Benselhoub Aissa

Inżynieria Materiałowa

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2024

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Vol. 45, nr 3

8--17

EN

The aluminum-enriched composite with the composition of Udimet 720 alloy was developed using an unconventional two-step sintering process. The first occurred at 1380°C for 0.5 h and the second at 1180°C for 3 h. The sintered material was then forged at 1200°C under a load of 50 kG and with a fall height of 220 mm, in order to achieve the clusters fragmentation of hard components, followed by the homogenization annealing at 800°C for 1.5 h. The consolidation technique included solution treatment at 1080°C and aging at 800°C with various holding times. The investigation techniques by X-ray diffraction analysis (XRD) and observations under a scanning electron microscope (SEM) with semi-quantitative analyses (EDS) have offered the possibility to reveal the aluminum addition’s impact and the holding time aging on the material’s microstructural evolution. The sintered alloy with a high Al content (5.25 %) exhibits a complex structure composed of metallic matrix γ, the chromium carbide Cr23 C6 , and a large variety of binary intermetallics. Despite this, the solution treatment caused an almost complete dissolution of these compounds, and consequently, a saturation of the nickel cubic lattice. An increase in precipitation phenomenon was, due to the formation of the intermetallic γ’ (Ni, Co)3 (Al, Ti), and then, the alloyed chromium carbide (Cr, Co, Ni, Mo, Ti)23 C6 , led to a noticeable hardening of the metal matrix, reaching a microhardness of 700 HV0.1.

PL

Opracowano kompozyt wzbogacony aluminium o składzie stopu Udimet 720 w niekonwencjonalnym dwuetapowym procesie spiekania. Kompozyt spiekano w temp. 1380°C przez 0,5 h, a następnie w temp. 1180°C przez 3 h. Spiekany materiał poddano kuciu w temp. 1200°C pod obciążeniem 50 kG i wysokości opadania 220 mm, w celu uzyskania fragmentacji skupień twardych składników, a następnie wyżarzaniu homogenizującym w temp. 800°C przez 1,5 h. Technika konsolidacji obejmowała obróbkę przesycającą w temp. 1080°C i starzenie w temp. 800°C z różnymi czasami przetrzymywania. Techniki badawcze polegające na analizie dyfrakcji promieni rentgenowskich (XRD) i obserwacje pod skaningowym mikroskopem elektronowym (SEM) wraz z analizami półilościowymi (EDS) umożliwiły ujawnienie wpływu dodatku aluminium i czasu utrzymywania starzenia na ewolucję mikrostruktury materiału. Spiekany stop o wysokiej zawartości Al (5,25%) wykazywał złożoną strukturę, na którą składały się: metaliczna osnowa γ, węglik chromu Cr23 C6 i duża różnorodność binarnych związków międzymetalicznych. Mimo to obróbka roztworowa spowodowała niemal całkowite rozpuszczenie tych związków, a w konsekwencji nasycenie sześciennej sieci niklu. Nasilenie zjawiska strącania osadów spowodowane utworzeniem się międzymetalicznego γ' (Ni, Co)3 (Al, Ti), a następnie stopowego węglika chromu (Cr, Co, Ni, Mo, Ti)23 C6 , doprowadziło do zauważalnego utwardzenia osnowy metalicznej, osiągającego mikrotwardość 700 HV0,1.

3

Effect of graphite nanoparticles on mechanical properties of FSPed aluminum surface composite

Kumar Dinesh, Singh Satnam

Composites Theory and Practice

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2024

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R. 24, nr 1

33--38

EN

Friction stir processing (FSP) is a manufacturing technique that can be employed to produce aluminum 6082 surface composites (ASCs). These ASCs display considerable increases in hardness and tensile strength, which makes them ideal for a wide variety of automotive applications. One example is piston skirts that are used in the cylinder chamber. The primary emphasis of this research is to investigate the accumulative impact that several passes have on Al 6082 surface composites that were filled with graphite nanopowder. The mechanical properties and microstructure of the fabricated composites were studied in order to accomplish this goal. The microstructural investigation showed that the graphite nanopowder particles were evenly distributed throughout the Al-6082 alloy. In addition, better dispersion of the graphite nanopowder was seen throughout the matrix material as the number of passes made during friction stir processing was increased. This may be explained by the reduction in grain size that occurs inside the aluminum metal matrix composites (AMMCs) that are produced as a consequence. According to the results of the research, the microhardness of the material grew to 105.3 HV after the third pass of the tool, and its maximum tensile strength rose to 215±3 MPa. In the ASCs that fabricated after three passes of friction stir processing, the smallest grain size that was measured was 24 micrometers.

4

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.

5

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.

6

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.

7

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.

8

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.

9

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.

10

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.

11

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.

12

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.

13

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.

14

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.

15

Evolution of zinc coatings during drawing process of steel wires

Suliga Maciej, Wartacz Radosław, Hawryluk Marek

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e120, 2023

EN

The paper shows a significant influence of the multi-stage wire drawing technology on deformability and phase transformations in the zinc coating. SEM tests proved that the coating after hot-dip galvanizing consists of a number of thin layers, ranging from 1 to 5 μm, and differing in thickness, chemical composition and properties. When pulled through the drawing die the zinc coating heats up (as a result of friction between the material and the tool) and its dynamic plastic deformation. It resulted in the fracture and partial crushing of the hard-intermetallic phases. It has been proven that as the wire passes through successive drawing dies, the coating is thinned and diffusion as well as phase remodelling of individual structural components occurs; in the place of phase ζ, the intermetallic phase δ1 develops, increasing its share in the diffusion layer. The crystals of intermetallic phases located on the border of the diffusion and outer layers break up and remain dispersed in the zinc. An analysis of the microhardness of the coating has proven that the level of the increase in the microhardness of the zinc coating is contingent on percentage of iron in particular layers of coating.

16

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.

17

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.

18

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.

19

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.

20

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.