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1

Efect of heat treatment parameters on microstructure evolution, tensile strength, wear resistance, and fracture behavior of Ni-Ti multilayered composites produced by cross‑accumulative roll bonding

Ye Qing, Li Xuejun, Tayyebi Moslem, Assari Amir Hossein, Polkowska Adelajda, Lech Sebastian, Polkowski Wojciech, Tayebi Morteza

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e27, 2023

EN

The last decades have seen a huge growth in the investigation of intermetallic compounds at the interfaces of laminated composites due to their useful features. In this research, efects of the formation of intermetallic compounds on tensile properties and wear resistance of Ni/Ti composites produced by cross-accumulative roll bonding (CARB) process have been examined at diferent annealing times and temperatures. Scanning electron microscopy (SEM) images demonstrated that the layers were well bonded together, but Ni layers experienced instabilities in light of plastic deformation. The EBSD results showed lamellar structure and crystallographic texture on Ti and Ni layers during plastic deformation. According to X-ray difractometer (XRD) and energy-dispersive spectrometer (EDS) analyses, NiTi2 and NiTi were present in all annealed samples. The thickness of intermetallic compounds grew with an increase in annealing temperature and time. However, this growth led to a decrease in tensile strength while the values of elongation fuctuated. Based on the results of the wear test, the composite became more resistant to wear when the thickness of intermetallic layers increased. The surfaces of these layers with less roughness and lower coefcients of friction facilitated the movement of steel pin on samples during the wear test. Furthermore, wear mechanisms of adhesion, abrasion, and delamination were observed, and they were more noticeable at higher loads and lower annealing temperatures and times.

2

The Comparative Analysis of Ecological Lubricants

Drabik Jolanta, Kozdrach Rafał, Wolszczak Marek, Michalski Janusz, Duszyński Grzegorz, Piątkowski Mariusz

Tribologia

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2022

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nr 4

17--22

EN

On the base of rheological tests, the resistance to deformation of lubricants elaborated on the base of Crambe abyssinica seed oil was evaluated. The developed lubricants were subjected to thermal and mechanical stresses, which allowed the evaluation of their resistance to the oxidation process and anti-wear properties. After tests, the rheological properties of tested lubricants were carried out by determining the complex modulus in oscillation tests. On the base of the rheological parameter, the resistance of lubricants to deformation and change of this indicator under the influence of thermal and mechanical stresses was evaluated. The carried out analysis of changes in the G* complex modulus showed that the tested lubricants show a different resistance to deformation depending on their type and depending on the impact of the extortion. It was found that the rheological index (complex modulus G*) determined in oscillation tests can be a successful criterion for the quality of pro-ecological lubricants.

PL

Na podstawie testów reologicznych oceniono odporności na deformację środków smarowych opracowanych na bazie oleju z nasion Crambe abyssinica. Opracowane środki smarowe poddano działaniu wymuszeń cieplnych i mechanicznych, co umożliwiło ocenę ich odporności na proces utleniania i właściwości przeciwzużyciowych. Po przeprowadzonych testach wyznaczono właściwości reologiczne badanych środków smarowych, wyznaczając moduł zespolony w testach oscylacyjnych. Na podstawie parametru reologicznego oceniono odporność smarów na odkształcenia i zmianę tego wskaźnika pod wpływem wymuszeń cieplnych i mechanicznych. Przeprowadzona analiza zmian modułu zespolonego G* wykazała, że badane środki smarowe wykazują zróżnicowaną odporność na odkształcenia w zależności od ich rodzaju oraz w zależności od oddziaływania wymuszeń. Stwierdzono, że wskaźnik reologiczny (moduł zespolony G*) wyznaczony w testach oscylacyjnych może z powodzeniem stanowić kryterium jakości proekologicznych środków smarowych.

3

Characteristics of hard coal and its mixtures with water subjected to friction

Jonczy Iwona, Wieczorek Andrzej N., Podwórny Jacek, Gerle Anna, Staszuk Marcin, Szweblik Jacek

Gospodarka Surowcami Mineralnymi

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2020

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T. 36, z. 3

185--202

EN

This paper deals with issues related to tribological processes occurring as a result of excessive wear of the surface of scraper conveyor components caused by the impact of the mined material created during drilling of development or exploitation galleries. One of the most common types of tribological wear is abrasive wear. Wear tests were carried out for hard coal – based abrasive using dry carbon abrasive and a hydrated mixture with 76 and 58% hard coal. Based on the conducted research, it was established that the effects of wear processes are associated with damage typical of wear mechanisms: micro-scratching and micro-fatigue. For the wear variant in the presence of dry coal abrasive, individual scratches caused by the abrasive grains were observed on the surface of the samples. The main reason for this type of damage was the aggregation of quartz, which is one of the basic components of the mineral substance present in the tested hard coal. When hydrated carbon mixtures were used as an abrasive, the surface of the samples also displayed scratches characteristic of the aggregate quartz. A small part of the carbon abrasive was pressed into the scratches. Under the influence of the wear caused by friction, small depressions were also formed, where coal penetrated. The effect of coal pressing into micro-scratches is related to its plastic properties. Tests of the abrasive conducted after the conclusion of wear tests have shown that under the influence of the local increase in temperature and pressure, the hard coal contained in the abrasive can undergo transformations. In the abrasive transformed under friction, small, but measurable changes in the content of the C element in relation to the initial hard coal sample were exhibited.

PL

W artykule poruszono problematykę związaną z procesami tribologicznymi zachodzącymi w wyniku nadmiernego zużycia powierzchni elementów przenośników zgrzebłowych wywołanych oddziaływaniem urobku powstającego w trakcie drążenia korytarzowych wyrobisk udostępniających lub eksploatacji węgla. Jednym z najczęściej spotykanych rodzajów zużycia tribologicznego jest zużycie ścierne. Testy zużyciowe przeprowadzono dla ścierniwa bazującego na węglu kamiennym, stosując suche ścierniwo węglowe oraz uwodnioną mieszaninę z udziałem 76 oraz 58% węgla. Stwierdzono, że efekty procesów zużyciowych związane są z uszkodzeniami typowymi dla mechanizmów zużycia: mikrorysowania i mikrozmęczenia. Dla wariantu zużycia w obecności suchego ścierniwa węglowego na powierzchni próbek zaobserwowano pojedyncze rysy wywołane działaniem ziaren ścierniwa. Główną przyczyną tego typu uszkodzeń była agregacja kwarcu, stanowiącego jeden z podstawowych składników substancji mineralnej występującej w badanym węglu kamiennym. W przypadku zastosowania jako ścierniwa uwodnionych mieszanin węgla, na powierzchni próbek również wytworzyły się charakterystyczne dla oddziaływania zagregowanego kwarcu rysy, w które wprasowywała się niewielka część ścierniwa węglowego. Pod wpływem zużycia wywołanego tarciem powstały również niewielkie wgłębienia, w które przedostał się węgiel. Efekt wprasowywania się węgla w mikrorysy związany jest z jego własnościami plastycznymi. Badania ścierniwa po zakończeniu testów zużyciowych wykazały, że pod wpływem lokalnego wzrostu temperatury i ciśnienia zawarty w ścierniwie węgiel kamienny może ulec przeobrażeniom. W ścierniwie przeobrażonym pod wpływem tarcia wykazano niewielkie, ale mierzalne zmiany zawartości pierwiastka C w stosunku do próbki wyjściowej węgla.

4

Friction and Wear Behavior of Direct Metal Deposition on SUH3

Choi Byungjoo, Cho In-Sik, Jung Do-Hyun, Lee Moon G., Jeon Yongho

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 3

841--844

EN

Poppet valves made from high-frequency heat-treated SUH3 steel have insufficient durability, and scratches appear on the valve face in prolonged use. It is necessary to develop surface treatment technology with excellent durability to prevent the deterioration of engine performance. Therefore, a surface treatment technology with higher abrasion resistance than existing processes was developed by direct metal deposition to the face where the cylinder and valve are closed. In this study, heat pretreatment and deposition tests were performed on three materials to find suitable powders. In the performance evaluation, the hardness, friction coefficient, and wear rate were measured. Direct metal deposition using Inconel 738 and Stellite 6 powders without heat pretreatment were experimentally verified to have excellent durability.

5

Microstructural, electrical, thermal and tribological studies of copper-fly ash composites through powder metallurgy

Thanga_Kasi_Rajan S., Balaji A. N., Narayanasamy P., Vettivel S. C.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 6

935--940

EN

This research work address the fabrication of copper (Cu) matrix composites, reinforced with fly ash (FA) particulates with 3, 6, 9 and 12 wt.% using the powder metallurgy route. The microstructural, physical, electrical, thermal, mechanical and tribological properties of thus fabricated Cu-FA composites have been studied. Optical microstructural characterization of the composites exposed persuasively uniform distribution of FA reinforcement with minimum porosity. The mixed powder SEM images revealed the homogeneous dispersion of fly ash particulates in the copper matrix. The hardness values showed improvement with increase in the weight percentage of FA in the Cu matrix. Electrical conductivity was measured using the four-point probe method at room temperature. Thermal conductivity was measured with a thermal diffusivity analyzer at room temperature. The fly ash addition leads to weakening the conductivity of Cu-FA composites. The tribological properties of Cu-FA composite specimens were investigated using a Pin-on-disc tribo testing machine against an EN81 steel contour disc. The specific wear rate of the composites tended first to decrease, which was attributed mainly to the formation of a mechanically mixed layer on the worn surface. Then it would increase as the FA content increased because of reduction in ductility and brittle oxide cracks associated with adding more FA particulates. It seems that composites with FA percentages below 9wt.% have optimum properties of microstructure, hardness and wear resistance, which is suitable for applications such as electrical sliding contacts, electrical discharge machining and spot welding electrodes.

6

Influence of aging solutions on wear resistance and hardness of selected resin-based dental composites

Chladek G., Basa K., Żmudzki J., Malara P., Nowak A. J., Kasperski J.

Acta of Bioengineering and Biomechanics

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2016

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Vol. 18, no. 3

43--52

EN

Purpose: The purpose of this study was to investigate the effect of different plasticizing aging solutions on wear resistance and hardness of selected universal resin-based dental composites. Methods: Three light cured (one nanofilled, two microhybride) and one hybride chemical cured composites were aged at 37 °C for 48 h in distillated water, ethyl alcohol solution or Listerine mouthwash. After aging the microhardness tests were carried out and then tribological tests were performed in the presence of aging solution at 37 °C. During wear testing coefficients of friction were determined. The maximal vertical loss in micrometers was determined with profilometer. Results: Aging in all liquids resulted in a significant decrease in hardness of the test materials, with the largest values obtained successively in ethanol solution, mouthwash and water. The effect of the liquid was dependent on the particular material, but not the type of material (interpreted as the size of filler used). Introduction of mouthwash instead of water or ethanol solution resulted in a significant reduction in the coefficient of friction. The lowest wear resistance was registered after aging in ethanol and for the chemical cured hybrid composite, but the vertical loss was strongly material dependent. Conclusions: The effect of different aging solution, including commercial mouthrinse, on hardness and wear was material dependent, and cannot be deduced from their category or filler loading. There is no simple correlation between hardness of resin-based dental composites and their wear resistance, but softening of particular composites materials during aging leads to the reduction of its wear resistance.

7

Primary Crystallization Studies and Abrasion Analysis of Cr-Ni-Mo Cast Steel

Studnicki A., Gromczyk M., Kondracki M., Suchoń J., Szajnar J.

Archives of Foundry Engineering

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2015

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Vol. 15, iss. 4

75--80

EN

The article shows results of studies of primary crystallization and wear resistance of Cr-Ni-Mo cast steel intended for work in corrosive and abrasive conditions. The studies of primary crystallization were conducted with use of TDA method and modified tester allowing measurement casting cooling time influence on the cooling and crystallization curves of studied alloys. After heat treatment of examined cast steel wear tests of the samples were conducted on pin-on-disc type device.