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1

Effects of ageing heat treatment temperature on the properties of DMLS additive manufactured 17-4PH steel

Świetlicki Aleksander, Wlaczak Mariusz, Szala Mirosław, Turek Marcin, Chocyk Dariusz

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 4

art. no. e146237

EN

Additive manufacturing (AM) is a modern, innovative manufacturing method that enables the production of fully dense products with high mechanical properties and complex shapes that are often impossible to obtain by traditional methods. The 17-4PH grade steel is often applied where high mechanical performance is required. 17-4PH, or AISI 630, is intended for precipitation hardening, an operation that combines solution and ageing treatments and is used to significantly change the microstructure of the steel and enhance its mechanical properties. This study investigates the effect of precipitation hardening on the properties of 17-4PH steel. To examine microstructure and morphology, metallographic tests were performed together with phase composition and chemical composition analyses. Mechanical parameters were determined via Vickers hardness testing and the Oliver-Pharr method. Samples were fabricated using direct metal laser sintering (DMLS), which is one of the powder bed fusion methods. The use of a constant solution treatment temperature of 1040_C and different ageing temperatures made it possible to evaluate the effects of ageing temperature on the mechanical properties and microstructure of 17-4PH. The presence of face-centered cubic FCC g-austenite and body-centerd cubic BCC a-martensite structures were detected. The tests revealed that – similarly to the wrought material – the highest hardness of 382_10:3 HV0:2 was obtained after ageing at 450_C. The nanoindentation test showed the same H/E ratio for the sample after fabrication and after solution treatment at 0.016769, but this value increased after ageing to 127–157.5%. The sample aged at 450_C was characterized by the highest H/E ratio of 0.026367, which indicates the highest wear resistance of this material under employed treatment conditions. In general, the sample treated at 450_C showed the best performance out of all tested samples, proving to have the smallest grain size as well as high Vickers and nanoindentation hardness. On the other hand, the use of solution treatment led to reduced hardness and improved workability of the AM material.

2

Nano-level mechanical and tribological behavior of additively manufactured AlSi10Mg plates

Murugesan Periyakaruppan, Satheeshkumar V., Jeyaprakash N., Prabu G., Yang Che-Hua

Archives of Civil and Mechanical Engineering

|

2023

|

Vol. 23, no. 1

art. no. e62, 2023

EN

This work focuses on the study of the selective laser melting (SLM) fabrication parameter of AlSi10Mg specimen. SLM parameters such as Power and scanning speed are varied to identify the defect-free samples. In addition, X-ray diffraction (XRD) analysis is carried out on the AM AlSi10Mg specimen to study the presence of phase. The results reveal that the Al matrix possesses (200), (220) and (311) phases whereas the AlSil0Mg powder has (111), (200), (220) and (311) phases. The microstructural characterization based on FESEM, TEM and EBSD analysis is carried out. The cross-section of the molten pool appears as a semi-cylindrical shape in the section that is parallel to the plane of powder deposition. The height, width and depth of the molten pool are measured as 150 ± 10 μm, 450 ± 10 μm and 50 ± 10 μm, respectively. TEM analysis reveals that the Si-precipitate and the eutectic Si element of the AM AlSi10Mg specimen are clearly formed in the AM AlSi10Mg specimen. Si precipitate spread within the grains whereas, the eutectic Si element is present at the grain boundary of the specimen. Then, the nanohardness and nanowear behavior are analyzed. Further, the influence of strain rate on the tensile strength is investigated. These mechanical tests are carried out on the defect-free AM AlSi10Mg specimen to assess its maximum performance. Very rough as well as irregular fracture surfaces are observed in the tensile test AM AlSi10Mg specimen. In addition to it, its magnified image reveals that the specimen fracture in the form of river patterns and contains a lot of micron-sized pores throughout the fracture surfaces.

3

Effect of pulse laser treatment at different process variables on mechanical behavior of carbon nanotubes electrophoretically deposited on titanium alloy

Majkowska-Marzec Beata, Staszewski Kacper, Sypniewska Joanna

Acta of Bioengineering and Biomechanics

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2023

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Vol. 25, no. 2

157--168

EN

Titanium and its alloys are widely used as biomaterials for long-term implants, but they are usually surface-modified due to their weak bioactivity and wear resistance. Laser processing was used to modify the surface layer, and elemental carbon was a component of the deposited coatings. This research aims to use a combination of both methods based on preliminary electrophoretic deposition of multi-wall carbon nanotubes (MWNCTs) followed by pulse laser treatment. Carbon nanotubes were chosen due to their mechanical and chemical stability as well as their tubular shape, resulting in enhanced mechanical properties of laser-modified layers. Methods: The pulse laser power and laser scanning speed were defined as variable process parameters. The microstructure, roughness Ra, nanohardness H, Young’s modulus E, and indent depth values were measured, and the H/E, H 3 /E2 , and relative changes of all these values in comparison to MWCNTs-coated and non-coated surfaces, were calculated. Results: The obtained results show that the best mechanical properties of MWCNTs-coated and laser-treated specimens are obtained at a laser power of 900 W and laser feed of 6 mm/s. The observed relations can be explained considering processes occurring on the surface such as deposition of carbon nanotubes, melting and re-crystallization of the surface layer, formation and possible partial decomposition of titanium carbides, and associated changes in local chemical composition, phase composition, and a level of residual stresses beneath the surface. Conclusions: The developed process can substitute the time and money-consuming carbonization of titanium and its alloys.

4

Surface Topography of Inconel 718 Alloy in Finishing WEDM

Buk Jarosław

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 1

47--61

EN

The properties of Iconel 718 determine its application for parts operating in extremely tough conditions. The difficulties when machining nickel-based superalloys allowed in recent years for researching other machining methods. One of the proposed methods is Wire Electrical Discharge Machining (WEDM). It becomes possible to minimize or eliminate such problems associated with electrical discharge machining as microcracks, forming of a white layer, or high surface roughness. One way to avoid these issues is to apply finishing machining. The literature indicates that the peak current is the main parameter responsible for shaping the machined surface in finishing WEDM. Furthermore, few works focus on the electrode’s infeed, in particular there are not many papers regarding the influence of the infeed on the machined surface parameters. Therefore, the paper aims to investigate on the influence of the peak current and infeed during finishing WEDM on the surface properties of Inconel 718. The paper presents measurements of selected surface topography parameters and Abbot Firestone curves (AFC). The presented plots allowed to determine the ranges of the process parameters for which the lowest surface roughness values were achieved. Cross-sections were performed to measure the thickness of a white layer. Nanohardness HV0,01 measured by Berkovich tip was recorded to determine the size of a heat affected zone (HAZ). The correlation between the peak current Ic and the infeed z regarding the machined surface quality was presented.

5

Nanocharacterization of metallic thin films deposited on different substrates

Merie Violeta V., Burnete Nicolae V., Bîrleanu Corina, Pustan Marius

Materials Science Poland

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2020

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Vol. 38, No. 1

8--16

EN

The purpose of this study was to determine the influence of different substrates (C45 steel, polycarbonate, glass) on the topography as well as tribological and mechanical properties (nanohardness, modulus of elasticity and friction force) of aluminum, gold and silver thin films. The 3D image analysis showed a strong influence of the substrate material on the topography of the studied thin films with no certain variation rule. Using the Oliver and Pharr method for determining nanohardness it was observed that, the smallest values were obtained for the thin films deposited on plastic substrate, followed by glass and C45 steel, regardless of the deposited material. The determination of the modulus of elasticity was done using the Hertzian method. The obtained results showed that the highest values of this parameter were obtained for the films deposited on plastic substrate, while the lowest values depended on both the deposited material and substrate. Friction force analysis for aluminum and gold showed a significant impact of the substrate material, with more constant values for gold. As a consequence, one must pay a particular attention when choosing the material for the substrate on which the thin films are deposited.

6

Nanohardness and elasticity of cell walls of Scots pine (Pinus sylvestris L.) juvenile and mature wood

Mania P., Nowicki M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2020

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Vol. 68, nr 5

1237--1241

EN

The aim of this study was to determine the hardness and reduced modulus of elasticity of juvenile wood of Scots pine (Pinus sylvestris L.) using the nanoindentation method, and then to compare the results obtained with those of mature wood. The hardness of juvenile pine wood determined by means of the nanoindentation method was 0.444 GPa while for mature wood it was 0.474 GPa. Statistically significant differences between the values were found. The reduced modulus of elasticity in juvenile wood was 14.0 GPa and 16.4 GPa in mature wood. Thus, the hardness values obtained were about 7% higher, while the modulus of elasticity was 17% higher in mature wood. All determinations were made in the S2-layer of the secondary cell wall.

7

An Analysis of Mechanical and Tribological Properties of Zr/Zr2N Multilayer Coatings

Kot Marcin, Lackner Jurgen, Major Łukasz, Szczęch Marcin, Wiązania Grzegorz, Zimowski Sławomir

Tribologia

|

2019

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nr 4

15--22

EN

The paper presents the analysis of effect of the Zr to Zr2N layer thickness ratios of 1:1, 1:2, and 1:4 on the mechanical properties of Zr /Zr2N multilayer coatings. With the increase in the amount of the ceramic phase in the multilayer coating, an increase in hardness from 11 to 14.5 GPa and Young's modulus from 158 to 211 GPa was observed. This was accompanied by improved scratch resistance as critical load LC2 raises from 17 to over 30 N. A ratio increase from 1:1 to 1:2 caused a 3-fold improvement in the coating wear resistance, which was also accompanied by a change in the wear mechanism. However, there was no further improvement of this parameter with a ratio increase to 1:4. Microscopic analysis of wear tracks, using the TEM technique revealed that the Zr metal layers change the direction of crack propagation. This phenomenon results in the improved fracture resistance of multilayer coatings compared to single coatings. Such a mechanism was even observed for the 1:4 coating with the thinnest 58 nm Zr layers.

PL

W pracy przedstawiono analizę wpływu stosunku grubości warstw Zr i Zr2N 1:1, 1:2 i 1:4 na właściwości mechaniczne powłok wielowarstwowych Zr/Zr2N. Wraz ze wzrostem udziału fazy ceramicznej w powłoce wielowarstwowej obserwowano wzrost jej twardości z 11 do 14,5 GPa i modułu Younga ze 158 do 211 GPa. Towarzyszyła temu także poprawa odporności na zarysowanie, o czym świadczy wzrost wartości obciążenia krytycznego LC2 z 17 do ponad 30 N. Wzrost stosunku z 1:1 do 1:2 powodował 3-krotną poprawę odporności na zużycie powłoki, czemu towarzyszyła także zmiana mechanizmu zużywania. Natomiast nie następowała dalsza poprawa tej cechy przy wzroście stosunku do 1:4. Analizy mikroskopowe torów tarcia przy użyciu techniki TEM wykazały, że warstwy metali Zr powodują zmianę kierunku propagacji pęknięć, co przekłada się na poprawę odporności na pękanie powłok wielowarstwowych w stosunku do powłok pojedynczych. Mechanizm taki obserwowano nawet dla powłoki 1:4, dla której grubość warstwy Zr była najmniejsza i wynosiła 58 nm.

8

Indentation testing of thin titanium coatings sprayed with cold gas

Makrenek M., Żórawski W.

Welding Technology Review

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2018

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R. 90, nr 11

20--22

EN

Material hardness is one of the basic parameters characterizing the properties of matter. In the nanohardness studies, the intendant’s deformation can not be neglected. Assuming the proportionality of the intender’s deformation to the hardness of the material being tested, a relative hardness measurement was used in the work. Hardness measurement was carried out for fused silica, which was a reference sample. With the same nanotesting parameters, a nanoscale measurement was carried out for two samples.

9

Adaptive coatings a-C/MoS2

Kot M., Lackner J., Major Ł., Major R., Skalski K., Wiązania G., Zimowski S.

Tribologia

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2018

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nr 2

51--56

EN

One of the latest ideas in surface engineering is the deposition of new kinds of coatings, called adaptive or chameleon. Based on literature review, the different mechanisms of the adaption of such coatings depend on the applied ranges of temperature and loads were compared. Moreover, the main directions of development of adaptive coatings were also presented. The paper includes results of single coatings, a-C and MoS2, as well composite coatings, a-C/MoS2, in which the mechanism of adaptation was expected. Indentation tests were carried out to determine nanohardness and elasticity modulus. The adhesion of coatings to steel substrates was studied by scratch testing, and tribological properties were studied using a high-temperature ball-on disc tribometer and tests results conducted at room temperature and at elevated temperatures up to 300°C. Results showed that composite coating, a-C/MoS2, can work over the entire range of temperatures with a low coefficient of friction 0.02–0.1 and wear index of 0.07–0.47•10–6 mm3/Nm. Whereas, a-C and MoS2 coatings exhibited a low coefficient of friction and a high wear resistance at low and high temperatures, respectively.

PL

W pracy przedstawiono nowy kierunek w inżynierii powierzchni tworzenia powłok adaptacyjnych, zwanych także kameleonowymi. Na podstawie analizy literatury zestawiono różne mechanizmy adaptacji powłok, w zależności od zakresu stosowanych temperatur pracy i kierunki rozwoju takich powłok. Przedstawiono także wyniki badań własnych dla powłok pojedynczych a-C i MoS2 i na ich tle wyniki dla powłok a-C/MoS2, w których spodziewano się mechanizmu adaptacji. Przeprowadzono testy indentacyjne, z których wyznaczono ich nanotwardość i moduł sprężystości. Analizowano także adhezję powłok do podłoży stalowych przy użyciu testu zarysowania. Testy tribologiczne przeprowadzono w temperaturze pokojowej oraz w podwyższonej do 300°C. Uzyskane wyniki wykazały, że w odróżnieniu do powłok a-C i MoS2 powłoki a-C/MoS2 mogą pracować w całym zakresie badanych temperatur. Wskazują na to niskie wartości współczynnika tarcia 0,02–0,1 i wskaźnika zużycia 0,07–0,47•10–6 mm3/Nm.

10

Using the taguchi method to optimize controlled variables in the experiment to produce a Ti coating by cold spraying

Makrenek M., Żórawski W., Góral A.

Technical Transactions

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2018

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Vol. 115, iss. 12

179--184

EN

The article presents a method for optimizing technological parameters utilizing the G. Taguchi procedure. Optimization algorithm of controlled variables was presented in order to obtain the greatest value of nanohardness, microhardness and elastic modulus.

PL

W artykule przedstawiono metodę optymalizacji parametrów technologicznych wykorzystującą procedurę G. Taguchi. Zaprezentowano algorytm optymalizacji zmiennych kontrolowanych, tak by uzyskać jak największą wartości nanotwardości, modułu elastyczności i mikrotwardości.

11

Wpływ parametrów szlifowania wgłębnego na nanotwardość i chropowatość powierzchni stali C45

Deja M., Stanisławska A., Szkodo M., Wszelak K.

Mechanik

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2018

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R. 91, nr 11

1026--1028

PL

Przedstawiono wyniki badań wpływu głębokości współbieżnego szlifowania powierzchni płaskich na chropowatość i nanotwardość warstwy wierzchniej stali C45 o strukturze ferrytyczno-perlitycznej i średniej wielkości ziarna 20 μm. Dla wszystkich wartości głębokości szlifowania uzyskano znaczny wzrost twardości warstwy wierzchniej przedmiotu obrabianego.

EN

The paper presents the results of investigations on the effect of the depth of concurrent grinding of flat surfaces on the roughness and nano-hardness of the surface layer of C45 steel with a ferritic-pearlitic structure and average grain size of 20 μm. A significant increase in the hardness of the surface layer of the workpiece was obtained for all grinding depths.

12

Coatings with advanced microstructure for biomedical applications

Kot M., Major Ł., Major R., Lackner J., Pontié M.

Tribologia

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2017

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nr 2

77--84

EN

The paper presents the effect of the complex architecture of Cr/CrN+a-C:H coatings on their mechanical and tribological properties. These advanced coatings were compared with CrN single coatings and Cr/CrN multilayers. All of them were deposited by the magnetron sputtering technique. The conducted tests allowed nanohardness, elasticity modulus, fracture toughness, and adhesion of coatings to steel substrates to be determined. Tribological tests were carried out under dry friction and in the presence of phosphate-buffered saline PBS and foetal bovine serum FBS. For all test conditions, the friction coefficient and the wear index of the produced coatings were determined. The lowest wear and the lowest coefficient of friction are exhibited by coatings with complex Cr/CrN+a-C:H architecture. Furthermore, they are also resistant to the highly corrosive PBS environment.

PL

W pracy analizowano wpływ złożonej architektury powłok Cr/CrN+a-C:H na ich właściwości mechaniczne i tribologiczne. Porównywano je z powłokami pojedynczymi CrN i wielowarstwowymi Cr/CrN, które wytwarzano techniką magnetronowego rozpylania. Przeprowadzone badania umożliwiły określenie twardości, modułu sprężystości, odporności na pękanie i adhezji do podłoża. Testy tribologiczne przeprowadzono w warunkach tarcia suchego oraz w obecności roztworu soli fizjologicznej PBS i surowicy cielęcej FBS. Dla wszystkich warunków tarcia określono współczynnik tarcia oraz odporność na zużycie wytworzonych powłok. Najmniejszym zużyciem oraz najmniejszymi wartościami współczynnika tarcia charakteryzowały się złożone powłoki Cr/CrN+a-C:H. Przy tym są one także odporne na oddziaływanie korozyjne roztworu PBS.

13

The impact of magnetron source power on mechanical properties and phase composition of TiB2 coatings

Rydzewski M., Kacprzyńska-Gołacka J., Słomka Z., Mazurkiewicz A., Smolik J.

Problemy Eksploatacji

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2016

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no. 4

53--61

EN

PVD coatings are widely used in the tool industry. They use hard materials, such as carbides, borides, and nitrides of metallic elements, because these materials have good wear resistance and stability at elevated temperatures. Titanium diboride-TiB2 is a very interesting compound used for coatings in the tool industry. The results of the analysis of research directions in the field of coatings and layers with special operating properties (high hardness, good thermal and electrical conductivity, and good corrosion resistance) indicate that coatings and layers based on TiB2 are one of the most effective materials that improve tool durability. The paper presents the mechanical properties of TiB2 coatings obtained using the magnetron sputtering method in the function of sputtering process power of TiB2 target. The paper includes hardness and Young' s modulus measurements performed with nanoindentation method, and phase composition analysis, and the evaluation of the microstructure and topography using a Hitachi TM3000 scanning electron microscope.

PL

Powłoki PVD znajdują powszechne zastosowanie w przemyśle narzędziowym. Do ich wytwarzania stosuje się twarde związki takie jak: węgliki, borki, azotki metali, które charakteryzują się dobrą odpornością tribologiczną oraz stabilnością w podwyższonej temperaturze. Dwuborek tytanu - TiB2 jest bardzo interesującym materiałem powłokowym, cieszącym się dużym zainteresowaniem w przemyśle narzędziowym. Analiza literatury w zakresie powłok funkcjonalnych (powłok o dużej twardości, dobrym przewodnictwie cieplnym i elektrycznym, dobrej odporności korozyjnej) wskazuje TiB2 jako jeden z najbardziej efektywnych materiałów zwiększających trwałość narzędzi przeznaczonych do obróbki powierzchniowej stopów metali nieżelaznych. W artykule przedstawiono właściwości mechaniczne powłok TiB2 otrzymanych z wykorzystaniem metody rozpylania magnetronowego w funkcji mocy rozpylania targetu TiB2. Artykuł zawiera pomiary twardości oraz modułu Younga, analizę struktury fazowej, badania mikrostruktury oraz badania odporności na pękanie cienkich powłok.

14

Analiza rozkładu nanotwardości w warstwie stykowej kruszywo-zaczyn betonów z dodatkiem popiołów lotnych

Golewski G. L.

Materiały Budowlane

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2016

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nr 11

38--39

PL

W artykule przedstawiono wyniki badań nanotwardości w warstwach stykowych kruszywo-zaczyn (Interfacial Transition Zone – ITZ) betonów z dodatkiem: 20 i 30% krzemionkowych popiołów lotnych (FA). Podczas eksperymentów analizowano obszar w ITZ kruszywa grubego z zaczynem w odległości: 5, 25, 50, 100 i 150 μm od granicy ziaren kruszywa grubego. Odciski w betonie wykonywano nanowgłębnikiem Berkovicha z zastosowaniem techniki DSI. Na podstawie rozkładów nanotwardości ustalono, że najbardziej heterogeniczna jest strefa ITZ w odległości 25 μm od ziarna kruszywa. Grubość ITZ wynosi: w betonie FA-20 ok. 50 μm, natomiast w betonie FA-30 – ponad 50 μm.

EN

This paper presents the results of nanohardness in the paste-aggregate Interfacial Transition Zones (ITZ) of concretes with the addition of: 0, 20 and 30% FA. An area in the ITZ of coarse aggregates with paste was analysed in the five measurement points during the experiments, i. e. at the distance of: 5, 25, 50, 100 and 150 μm from the grain boundary. The indents in concrete were create by Berkovich indenter using DSI technique. On the basis of nanohardness distributions in particular concretes, it was found that the most heterogeneous one is the ITZ zone within the distance of 25 μm from the aggregate grain. The Thickness of the ITZ is: in concrete FA-20 approximately 50 μm, while in concrete FA-30 more than 50 μm.

15

Microstructure studies of nickel-carbon nanotubes nanocomposite coatings formed by electrodeposition

Popławski K., Kucharska B., Jezierska E., Sobiecki J. R.

Inżynieria Materiałowa

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2016

|

Vol. 37, nr 1

16--22

EN

Many researchers nowadays concentrate on nanocrystalline metal-matrix composites, as well as on composites reinforced by nanoparticles, to find more suited materials to be used in aviation, nuclear power plants or as a hydrogen storage for fuel cells. The aim of this paper was to investigate the possibility of producing nanocrystalline nickel-based composite coatings reinforced by carbon nanotubes (Ni–CNT). The goal was to obtain well immersed carbon nanotubes fully dispersed in nanocrystalline nickel matrix by using standard electrochemical deposition equipment and modify the process by changing parameters like bath composition, additives, nanotubes content or stirring method. The effect of optimization of these parameters on composite’s microstructure, surface topography and nanohardness was investigated. Also, usefulness of different approach, so called “stirring electrode” was examined. Scanning electron microscopy, transmission electron microscopy with electron diffraction, X-ray diffraction and Raman spectroscopy were used to determine the microstructure of obtained coatings.

PL

Celem tej pracy była ocena możliwości wytworzenia powłoki kompozytowej na osnowie nanokrystalicznego niklu z dodatkiem nanorurek węglowych (Ni–CNT), ze spełnieniem warunku otrzymania materiału z dobrze zdyspergowanymi i połączonymi z nanokrystaliczną osnową nanorurkami, za pomocą typowej metody osadzania elektrochemicznego i standardowego w tej metodzie sprzętu, modyfikując jedynie parametry procesu osadzania takie, jak: skład kąpieli, dodatek substancji modyfikujących czy powierzchniowo czynnych, zawartość nanorurek w kąpieli oraz metoda mieszania.

16

Ocena własności fizykochemicznych warstwy SiO2 w warunkach odkształcenia

Król A., Walke W., Basiaga M., Karasiński P.

Aktualne Problemy Biomechaniki

|

2016

|

z. 11

81--86

PL

W pracy przeprowadzono badania odporności korozyjnej, twardości oraz adhezji warstwy SiO2 naniesionej na powierzchnię stopu Ni-Ti. Badania realizowano zarówno dla próbek nieodkształconych, jak i odkształconych. Badania odporności na korozję przeprowadzono metodą potencjodynamiczną i impedancyjną w warunkach symulujących środowisko tkankowe – roztwór Ringera. Z kolei adhezję warstwy do podłoża oceniano metodą zarysowania (scratch-test). Do wyznaczenia twardości warstwy zastosowano metodę Vickersa wykorzystując wgłębnik Berkovicha. Przeprowadzone badania nie wykazały znaczących zmian własności fizykochemicznych warstw poddanych odkształceniu w stosunku do warstw nieodkształconych.

EN

The project preformed researches corrosion resistance, hardness and adhesion of SiO2 layer on Ni-Ti alloy. Researches were realized on deformed and not deformed specimen. Corrosion resistance research was performed by using potentiodynamic and impedance methods in conditions which simulate tissue environment – Ringer solution. Adhesion layer to metal substrate was evaluate by scratch test method. To get the hardness of layer the Vickers method with indenter Berkovich was used. The studies which were done did not show significant changes of physical-chemical properties for deformed and not deformed specimen.

17

Badania nanoindentacyjne powłok natryskanych metodą HVOF

Makrenek M., Żórawski W.

TTS Technika Transportu Szynowego

|

2015

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R. 22, nr 12

1016--1018, CD

PL

W artykule przedstawiono analizę nanotwardości w zależności od odległości od powierzchni warstwy. Opierając się na teorii zaproponowanej przez W.C. Oliver et al. i modelu proporcjonalności zaproponowany przez Bandyopadhyay P.P et al przeskalowano zmienne tak by otrzymać liniową zależność wiążącą siłę wciskającą wgłębnik z kwadratem głębokości penetracji. Nachylenie prostej zdeterminowane jest twardością materiału, a wszelkie odstępstwa od liniowości związane są z niejednorodnością struktury materiału.

EN

The article presents an analysis of nanohardness depending on the distance from the surface layer. Based on the theory proposed by WC Oliver et al. and proportionality model proposed by Bandyopadhyay et al PP scaled variables so as to obtain a linear relationship linking the indenter pressingin force with the square of the depth of penetration. The slope is determined by the hardness of the material, and any deviation from linearity are associated with inhomogeneity of the material structure.

18

Nano-hardness of the material of thin layers of the injector tip depending on the depth under the precisly finished co-operating surfaces

Miszczak A., Kuznetsova T., Czaban A.

Journal of KONES

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2015

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Vol. 22, No. 3

155--160

EN

In this paper, the authors present the results of experimental studies of the nano-hardness and Young's modulus of the injector spray pattern body and needle (the tip of the injector). The nano-hardness of a thin-layer of precisely finished co-operating surfaces was tested according to the depth below the surface of the sample (deep into the material). The quality of precisely finished surfaces of a fuel infector has a very large impact on the proper operation of a diesel engine. Both, the needle and the body of the injector spray pattern, are individually adjusted and lapped to maintain the proper gap between them. The gap between the needle and the injector tip body affects the proper dosage and quality of the sprayed fuel. Impurities in the fuel are of the same order of magnitude or even greater than this gap. Hard particles that penetrate between the side surfaces of the needle and body of the injector tip could result in scratching, which generate leaks and drops of injection pressure, increased fuel consumption, poor spraying of fuel, leaking of fuel to the lubricating oil and reduction of its operating properties. The hardness of the precisely finished surfaces of the injector is essential in the process of wear of these surfaces. The aim of the study was to determine the hardness and Young's modulus of thin layers of precisely finished co-operating surfaces of injector tip and estimation of the thickness of these layers. The nano-hardness measurements were made with the Hysitron TI 950 TriboIdenter, where the test is conducted using a nano-indenter with a mechanical method. The device allows selecting from several to several dozen of measurement points and performs automatic measurement of nano-hardness and Young's modulus in the indicated locations. The study concerns the tip (body and needle) of the non-used Bosch DLLA 160 S 1305 injector. The presented results can be used to develop some new methods of coating the co-operating surfaces with the hard thin layers, e.g. the use of titanium in order to decrease wear and increase scratching resistance.

19

Study On Nanohardness Of Phases Occurring In ZnAl22Cu3 And ZnAl40Cu3 Alloys

Michalik R., Chmiela B.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2A

621--626

EN

Zn-Al alloys are mainly used due to their high tribological and damping properties. A very important issue is determination of the hardness of the phases present in the Zn-Al-Cu alloys. Unfortunately, in literature there is lack of studies on the hardness of the phases present in the alloys Zn-Al-Cu. The aim of this research was to determine the hardness of the phases present in the ZnAl22Cu3Si and ZnAl40Cu3Si alloys. The scope of the research included examination of the structure, chemical composition of selected micro-regions and hardness of phases present in the examined alloys. The research carried out has shown, that CuZn4 phase is characterized by a similar hardness as the hardness of the interdendritic areas. The phases present in the structure of ZnAl40Cu3 and ZnAl22Cu3 alloys after soaking at the temperature of 185°C are characterized by lower hardness than the phase present in the structure of the as-cast alloys.

PL

Stopy Zn-Al stosowane są przede wszystkim z uwagi na swoje wysokie właściwości tribologiczne i tłumiące. Bardzo ważnym zagadnieniem jest określenie twardości faz występujących w stopach Zn-Al-Cu. W literaturze brak jednak opracowań dotyczących twardości faz występujących w stopach Zn-Al-Cu. Celem przeprowadzonych badań było określenie twardości faz występujących w stopach ZnAl22Cu3Si oraz ZnAl40Cu3Si. Zakres badań obejmował badania struktury, składu chemicznego w wybranych mikroobszarach oraz badania twardości faz występujących w badanych stopach. Przeprowadzone badania wykazały, że faza CuZn4 charakteryzuje się zbliżoną twardością do twardości obszarów międzydendrytycznych. Fazy obecne w strukturze stopów ZnAl22Cu3 oraz ZnAl40Cu3 po wygrzewaniu w temperaturze 185°C charakteryzują się mniejszą twardością niż fazy obecne w strukturze stopów w stanie po odlaniu.

20

Badania porównawcze nanotwardości i zredukowanego modułu Younga wybranych materiałów

Rokosz K., Hryniewicz T., Rzadkiewicz S.

Pomiary Automatyka Kontrola

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2014

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R. 60, nr 10

917--919

PL

W artykule przedstawiono badania twardości i zredukowanego modułu Younga próbek tytanu Ti i jego stopów Ti-13Nb-13Zr, Ti-24Nb-4Zr-8Sn, niobu Nb i stali nierdzewnej 0H17N14M2. Badania wykonano w VŠB-TU Ostrava (Czechy) nanoindenterem TI 950 TriboIndenter firmy Hysitron. Wyniki przedstawiono w formie wykresów słupkowych oraz w formie tabelarycznej zawierającej przedziały uzyskanych wartości badanych własności mechanicznych materiałów.

EN

The article presents the studies of reduced Young's modulus and hardness of titanium and its alloys, niobium and stainless steel samples, conducted in VŠB-TU Ostrava (Czech Republic) with using nanoindenter Hysitron TI 950 TriboIndenter. The samples by abrasive polishing using Struers Tegra Pol 35 were prepared. Mechanical treatment was carried out by setting the force of 10 N and the rotation speed of 200 min-1, and using abrasive papers successively a grain size of 320, 800, 1000 and 1200 μm. Diamond polishing paste of grain size from 3 to 1 μm to get best surface were used. Measurements showed, that the highest nanohardness revealed niobium (8.11 GPa), the lowest austenitic steel 00H17N14M2 (3.69 GPa). The highest value of reduced Young's modulus was measured for austenitic steel 00H17N14M2 (194.94 GPa), the lowest for titanium alloy Ti-13Nb-13Zr (89.19 GPa). In addition, it was found that the alloy structure and its composition influence the values of the hardness and reduced Young’s modulus.