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Wyszukujesz frazę "sliding surface" wg kryterium: Temat


Tytuł:
Sliding mode control of periodic review perishable inventories with multiple suppliers and transportation losses
Autorzy:
Bartoszewicz, A.
Maciejewski, M.
Powiązania:
https://bibliotekanauki.pl/articles/200764.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
discrete time sliding mode control
sliding surface design
inventory control
Opis:
The purpose of this paper is to develop robust and computationally efficient supply chain management strategy ensuring fast reaction to the demand variations for periodic review perishable inventory systems. For that purpose, we apply a sliding mode approach and we propose a new discrete time warehouse management strategy. The strategy employs the sliding hyperplane appropriately designed to ensure a dead-beat performance of the closed loop system. Our strategy not only explicitly takes into account decay of goods stored in the warehouse (perishing inventories) but it also accounts for transportation losses which take place on the way from suppliers to the warehouse. The proposed strategy ensures full customers’ demand satisfaction, minimizes the on-hand inventory volume and prevents from exceeding the warehouse capacity. This reflects the need of simultaneous minimization of the lost sales costs and inventory holding costs. Furthermore, the strategy ensures that the ordered quantities of goods are always non-negative and upper bounded. These favourable properties of the proposed strategy are formally stated as a lemma and three theorems and proved in the paper.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2013, 61, 4; 885-892
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of sliding surface on the performances of adaptive sliding mode slip ratio controller for a HEV
Autorzy:
Dash, B. K.
Subudhi, B.
Powiązania:
https://bibliotekanauki.pl/articles/229381.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sliding mode control
slip ratio control
hybrid electric vehicle
sliding surface
ABS
Opis:
Slip ratio control of a ground vehicle is an important concern for the development of antilock braking system (ABS) to avoid skidding when there is a transition of road surfaces. In the past, the slip ratio models of such vehicles were derived to implement ABS. It is found that the dynamics of the hybrid electric vehicle (HEV) is nonlinear, time varying and uncertain as the tire-road dynamics is a nonlinear function of road adhesion coefficient and wheel slip. Sliding mode control (SMC) is a robust control paradigm which has been extensively used successfully in the development of ABS of a HEV. But the SMC performance is influenced by the choice of sliding surface. This is due to the discontinuous switching of control force arising in the vicinity of the sliding surface that produces chattering. This paper presents a detailed study on the effects of different sliding surfaces on the performances of sliding mode based adaptive slip ratio control applied to a HEV.
Źródło:
Archives of Control Sciences; 2013, 23, 2; 187-203
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of the distribution of variable characteristics determining the asymmetry of the sealing rings sliding surfaces on the values of friction loss coefficients and other selected parameters of oil film
Autorzy:
Wróblewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/133559.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
rings asymmetrical sliding surface
friction loss
oil film
straty tarcia
film olejowy
Opis:
The article presents the results of research on the effect of the change in coordinates that determine the location of the common vertex of the parabolas and ellipses demonstrating the asymmetric shape of the rings sliding surfaces on the change in the thickness of oil film, the amount of scraped oil, and the oil left on the cylinder wall, once a set of selected sealing rings has passed, as well as the results concerning friction losses. Mathematical relationships of the asymmetric shapes of the rings sliding surfaces were presented, and the values of coefficients characterizing selected parameters of oil film and friction losses were determined. It was confirmed that there is a large dependence of the coordinate values of the vertices determining the asymmetric shapes of these surfaces on the condition and cooperation between piston rings and the cylinder bearing surface, and mainly on the amount of the oil scraped in the selected engine strokes.
Źródło:
Combustion Engines; 2017, 56, 4; 107-116
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of PI sliding mode control for Zeta DC-DC converter in PV system
Autorzy:
Hasanah, Rini Nur
Ardhenta, Lunde
Nurwati, Tri
Setyawati, Onny
Sawitri, Dian Retno
Suyono, Hadi
Taufik, Taufik
Powiązania:
https://bibliotekanauki.pl/articles/2173675.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
photovoltaic
Zeta converter
sliding mode control
PI sliding surface
fotowoltaika
konwerter Zeta
sterowanie trybem przesuwnym
powierzchnia ślizgowa PI
Opis:
Solar energy has become one of the most potential alternative energies in the world. To convert solar energy into electricity, a photovoltaic (PV) system can be utilized. However, the fluctuation of sunlight intensity throughout the day greatly affects the generated energy in the PV system. A battery may be beneficial to store the generated energy for later use. A DC–DC converter is commonly exploited to produce a constant output voltage during the battery charging process. A Zeta converter is a DC–DC converter which can be used to produce output values above or below the input voltage without changing the polarity. To deal with the inherent non-linearity and time-varying properties of the converter, in this paper the sliding mode control (SMC) is first analyzed and exploited before being integrated with a proportional-integral (PI) control to regulate the output voltage of the PV system. Disturbances are given in the form of changes in input voltage, reference voltage, and load. Voltage deviation and recovery time to reach a steady-state condition of the output voltage after disturbances are investigated and compared to the results using a proportional-integral-differential (PID) controller. The results show that the proposed control design performs faster than the compared PID control method.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 3; art. no. e140952
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PD terminal sliding mode control using fuzzy genetic algorithm for mobile robot in presence of disturbances
Autorzy:
Benaziza, W.
Slimane, N.
Mallem, A.
Powiązania:
https://bibliotekanauki.pl/articles/384371.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
mobile robot
fast terminal function
PD sliding surface
fuzzy system
genetic algorithm
Lyapunov stability
robot mobilny
system rozmyty
algorytm genetyczny
Stabilność Lapunova
Opis:
This paper presents a new approach in the field of trajectory tracking for nonholonomic mobile robot in presence of disturbances. The proposed control design is constructed by a kinematic controller, based on PD sliding surface using fuzzy sliding mode for the angular and linear velocities disturbances, in order to tend asymptotically the robot posture error to zero. Thereafter a dynamic controller is presented using as a sliding surface design, a fast terminal function (FTF) whose parameters are generated by a genetic algorithm in order to converge the velocity errors to zero in finite time and guarantee the asymptotic stability of the system using a Lyapunov candidate. The elaborated simulation works in the case of different trajectories confirm the robustness of the proposed approach.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2018, 12, 2; 52-60
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of asymmetric elliptical shapes of the sealing ring sliding surface on the main parameters of the oil film
Autorzy:
Wróblewski, P.
Powiązania:
https://bibliotekanauki.pl/articles/133158.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
rings with asymmetrical sliding surface shape
friction loss
oil film
quantification of lubricant oil consumption
straty tarcia
film olejowy
zużycie oleju smarowego
Opis:
This article discusses the results of simulation studies of the effect of selected sealing ring sets with asymmetrical elliptical sliding surfaces on the oil layer thickness distribution over the whole operating range of an internal combustion engine. The problem of calculating the sliding surface coverage with visco-elastic oil film as well as in mixed friction conditions is discussed. The effect of asymmetrical elliptical sliding surfaces particularly on the dimensionless slip and squeeze indicators was determined, defining these surfaces ability to produce an oil film. The research results presented in this article show that there exists a real possibility of friction loss reduction in the cylinder and sealing rings contact area, while maintaining the oil film continuity between the sliding surfaces.
Źródło:
Combustion Engines; 2017, 56, 1; 84-93
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Geometry of shape of profiles of the sliding surface of ring seals in the aspect of friction losses and oil film parameters
Geometria profilu powierzchni ślizgowej pierścieni uszczelniających w aspekcie strat tarcia i parametrów filmu olejowego
Autorzy:
Wróblewski, P.
Iskra, A.
Powiązania:
https://bibliotekanauki.pl/articles/133483.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
friction losses
profile of ring sliding surface
oil film
internal combustion engine
straty tarcia
profil powierzchni ślizgowej pierścieni
film olejowy
silnik spalinowy
Opis:
The article describes the results of simulations of the approved variations of sliding surfaces of ring seals in relation to a reference symmetrical barrel profile which is most often used in piston internal combustion engines. In particular the paper discusses the impact of the five assumed variants of sliding profiles of ring seals onto the thickness of oil film left on the cylinder face by a bottom and upper ring seal, the distribution of internal friction force in oil film between the ring seal set and the cylinder face, finally the oil film cover on a sliding surface of the upper ring seal. The results presented in the article show a close relationship between the sliding surface profile of ring seals and a unit oil consumption. A relationship between these parameters for the elements lying in the movement plane of a wrist pin axis was proven, as well as for the one lying in the plane perpendicular to it. Exemplary parameters of oil film and friction losses were presented while assuming a constant total axial values of the height and depth of circumferential grooves. The shapes of these grooves on the sliding surface of the ring seals in free state can be made with electroerosion microprocessing or ablative laser microprocessing.
W artykule omówiono wyniki badań symulacyjnych różnych wariantów profili powierzchni ślizgowej pierścieni uszczelniających w porównaniu do referencyjnego profilu baryłkowego symetrycznego. W szczególności przybliżono wpływ pięciu przykładowych wariantów profili powierzchni pierścieni uszczelniających na grubość warstwy oleju pozostawionej na gładzi cylindra przez dolny i górny pierścień uszczelniający, rozkład siły tarcia wewnętrznego w filmie olejowym między pakietem pierścieni uszczelniających a gładzią cylindra oraz przebieg pokrycia filmem olejowym profilu powierzchni górnego pierścienia uszczelniającego. Zaprezentowane w artykule wyniki badań wskazują na zależności jednostkowego zużycia oleju od profilu powierzchni ślizgowej pierścieni uszczelniających. Wykazano różnice tych zależności dla tworzących leżących w płaszczyźnie ruchu osi sworznia tłokowego oraz w płaszczyźnie prostopadłej do tej płaszczyzny. Przedstawiono przykładowe parametry filmu olejowego i strat tarcia przy założeniu stałej sumarycznej wartości szerokości i głębokości rowków obwodowych. Rowki te systematyzowano w wybranych kombinacjach na powierzchni ślizgowej pierścieni uszczelniających. Kształty tych rowków na powierzani ślizgowej pierścienia w stanie swobodnym otrzymuje się za pomocą mikroobróbki elektroerozyjnej i technologii ablacyjnej mikroobróbki laserowej.
Źródło:
Combustion Engines; 2016, 55, 4; 38-52
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved dynamic surface sliding mode method for autonomous cooperative formation control of underactuated USVS with complex marine environment disturbances
Autorzy:
Dong, Zaopeng
Qi, Shijie
Yu, Min
Zhang, Zhengqi
Zhang, Haisheng
Li, Jiakang
Liu, Yang
Powiązania:
https://bibliotekanauki.pl/articles/32909478.pdf
Data publikacji:
2022
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
underactuated USV
dynamic surface sliding mode control
lateral velocity tracking differentiator
nonlinear disturbance observer
Opis:
In this paper, a novel dynamic surface sliding mode control (DSSMC) method, combined with a lateral velocity tracking differentiator (LVTD), is proposed for the cooperative formation control of underactuated unmanned surface vehicles (USVs) exposed to complex marine environment disturbances. Firstly, in view of the kinematic and dynamic models of USVs and the design idea of a virtual control law in a backstepping approach, the trajectory tracking control problem of USVs’ cooperative formation is transformed into a stabilisation problem of the virtual control law of longitudinal and lateral velocities. Then, aiming at the problem of differential explosion caused by repeated derivation in the process of backstepping design, the first-order low-pass filter about the virtual longitudinal velocity and intermediate state quantity of position is constructed to replace differential calculations during the design of the control law, respectively. In order to reduce the steady-state error when stabilising the virtual lateral velocity control law, the integral term is introduced into the design of the sliding mode surface with a lateral velocity error, and then the second-order sliding mode surface with an integral is structured. In addition, due to the problem of controller oscillation and the role of the tracking differentiator (TD) in active disturbance rejection control (ADRC), the LVTD is designed to smooth the state quantity of lateral velocity. Subsequently, based on the dynamic model of USV under complex marine environment disturbances, the nonlinear disturbance observer is designed to observe the disturbances and compensate the control law. Finally, the whole cooperative formation system is proved to be uniformly and ultimately bounded, according to the Lyapunov stability theory, and the stability and validity of the method is also verified by the simulation results.
Źródło:
Polish Maritime Research; 2022, 3; 47-60
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tribological properties of surface layer with boron
Autorzy:
Lubas, J.
Powiązania:
https://bibliotekanauki.pl/articles/242091.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
wear
sliding friction
surface treatment
boron
Opis:
The aim of the present work is to determine the influence of technologically produced boron surface layers on the friction parameters in the sliding pairs under the conditions of mixed friction. The tribological evaluation included ion nitrided, pack borided, laser borided, quenched and tempered surface layers and TiB2 coating deposited on 38CrAlMo5-10, 46Cr2 and 30MnB4 steels. Modified surface layers of annular samples were matched under test conditions with counter-sample made from AlSn20 bearing alloy. Tested sliding pairs were lubricated 15 W/40 Lotos mineral engine oil. The tribological tests were conducted on a T-05 block on ring tester. The applied steel surface layer modification with boron allow creating surface layers with pre-determined tribological characteristics reąuired for the elements of kinematic pairs operating in the conditions of sliding friction. Pack boronizing reduces the friction coefficient during the start-up of the frictional pair and the maximum start-up resistance level is similar to the levels of pairs with nitrided surface layers. Paper present comparison between surface roughness of annular sample and countersample before and after test, influence of surface treatment annular sample on change of friction coefficient vs. rotation speed and load, influence of surface treatment annular sample on moment of friction in function load of kinematics pair, influence of surface treatment annular sample on friction forces and temperature depending on load, as well as influence of surface treatment annular sample on wear of AlSn20 bearing alloy under various load conditions.
Źródło:
Journal of KONES; 2009, 16, 3; 213-221
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The application of CrN and TiN coatings in slide bearing kinematic coupling pin surface layer modification processes
Autorzy:
Lubas, J.
Powiązania:
https://bibliotekanauki.pl/articles/244165.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
TiN
CrN
wear
sliding friction
surface treatment
Opis:
This work presents the results of tribological stand tests of slide bearings with pins modified with CrN and TiN coatings and pins with a TiN-steel 46Cr2 and CrN-steel 46Cr2 ,,ring" structure. The ,,rin" structure samples features materials with different tribological properties in the form of rings on the pin slide surface. Such a structure is obtained when covering the 46Cr2 steel pin base with a discrete layer of TiN or CrN, using the PVD method. The stand tests of frictional couplings have been performed for the frictional kinematic coupling pin with modified surface layer and CuPb30 and AlSn20 alloy bearing liner slice. During the tests the tribological couplings were lubricated with Castrol magnatec engine oil (5W/40). The tests were performed on a T-05 tribological tester. The test results demonstrated the tribological advantageous using the "ring" structure samples in the frictional couplings. The tests demonstrated that the friction forces and the bearing material quantity wear were the least for couplings with CrN steel, 46Cr2 and nitrogen hardening, and the largest for TiN pin couplings. Modification of the CrN pin surface layer has a beneficial impact on reducing frictional resistance, and temperature reduction in the friction area as well as reduction in bearing alloy wear.
Źródło:
Journal of KONES; 2008, 15, 2; 263-267
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tribological properties of sliding pairs with surface layer containing boron under mixed friction conditions
Autorzy:
Lubas, J.
Powiązania:
https://bibliotekanauki.pl/articles/242626.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
surface treatment
wear
sliding friction
boron
bearing alloy
Opis:
The aim of the present work is to determine the influence of surface layers containing boron on the friction parameters in sliding pairs under mixed friction conditions. The tribological evaluation included three production methods of surface layers with boron; pack boronizing, laser boronizing, and TiB2 coating deposited on 46Cr2 steel. Modified surface layers of ring specimens with 46Cr2 steel were matched under test conditions with a counterpart made from AlSn20 bearing alloy. Tested sliding pairs were lubricated with 5W/40 Lotos synthetic engine oil. The applied modification technologies of the surface layer of steel allowed for obtaining construction materials with predetermined tribological characteristics required for the elements of sliding pairs working undermixed friction conditions. The results showed differences in the wear of bearing alloy, as the effect of the interaction between the cooperating surface layers and of the physiochemical changes of their surfaces, induced by external forces. The TiB2 coating generated the highest friction resistance and bearing alloy wear. The pack borided surface layer reduces the friction coefficient, the moment during the start-up of the frictional pair and the wear of the bearing material. The analysis of the surface layer indicated that the content of aluminum on pack borided ring specimens reached 21%, and on the TiB2 coating, it exceeded 8%.
Źródło:
Journal of KONES; 2013, 20, 1; 185-192
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of sliding friction of WC-Co composite on particleboard
Autorzy:
Wilkowski, Jacek
Barlak, Marek
Jałocha, Radosław
Werner, Zbigniew
Auriga, Alicja
Powiązania:
https://bibliotekanauki.pl/articles/2200135.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
WC-Co composites
particleboard
sliding friction
surface roughness
Opis:
Analysis of sliding friction of WC-Co composite on particleboard. The paper presents the analysis of the coefficient of friction at the contact area between WC-Co composite and particleboard. The four types of WC-Co composite in the form of milling indexable knives for wood materials machining were tested. The tests were carried out on a linear reciprocating tribotester (pin-on-flat), where the sample was the clearance surface of WC-Co indexable knives and the counter-sample was made of three-layer particleboard. Before and after tribological tests, the surface roughness of tested knives was measured. The highest values of friction coefficient were obtained for the type UMG04 of cemented carbide - with nano size of WC grains and the lowest content of cobalt. The average coefficient of friction for selected types of WC-Co correlated with the average increase in surface roughness (the roughness parameter Ry).
Analiza tarcia ślizgowego kompozytu WC-Co w kontakcie z płytą wiórową. Artykuł przedstawia analizę współczynnika tarcia na styku kompozyt WC-Co i płytay wiórowaej. Przebadano cztery rodzaje kompozytu WC-Co w postaci frezarskich noży wymiennych do obróbki materiałów drzewnych. Badania przeprowadzono na tribotesterze typu „trzpień po płaszczyźnie”, gdzie próbką była powierzchnia przyłożenia noża wymiennego WC-Co, a przeciwpróbką był trzpień wykonany z trójwarstwowej płyty wiórowej. Przed i po badaniach tribologicznych dokonano pomiaru chropowatości powierzchni badanych noży. Najwyższe wartości współczynnika tarcia uzyskano dla rodzaju węglika UMG04 o najdrobniejszych ziarnach WC i najniższej zawartości kobaltu. Średni współczynnik tarcia dla poszczególnych rodzajów WC-Co korelował ze średnim przyrostem chropowatości wyrażonej parametrem Ry.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2020, 111; 60--67
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adaptive sliding mode control for ship autopilot with speed keeping
Autorzy:
Liu, Z.
Powiązania:
https://bibliotekanauki.pl/articles/259349.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
surface vessel
speed loss
adaptive control
course keeping
sliding mode control
Opis:
The paper addresses an important issue in surface vessel motion control practice that the ship dynamics and sailing performance can be affected by speed loss. The vessel speed is significantly decreased by the added resistance generated by waves. An adaptive sliding mode course keeping control design is proposed which takes into account uncertain ship dynamics caused by forward speed variations, while avoiding performance compromises under changing operating and environmental conditions. The sliding mode control provides robust performance for time-varying wave disturbances and time-varying changes in ship parameters and actuator dynamics. After combining the unknown but bounded system uncertainties, the design of the adaptation law is obtained which is based on the Lyapunov’s direct method. Simulations on a ship with two rudders illustrate the effectiveness of the proposed solution.
Źródło:
Polish Maritime Research; 2018, 4; 21-29
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Właściwości tribolgiczne warstwy wierzchniej z borem w warunkach tarcia ślizgowego
Tribological characteristics of the surface layer with boron under sliding friction onditions
Autorzy:
Lubas, J.
Powiązania:
https://bibliotekanauki.pl/articles/190836.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
tarcie ślizgowe
zużycie
obróbka powierzchniowa
bor
sliding friction
wear
surface treatment
boron
Opis:
Właściwości tribologiczne par ciernych zależą od ich konstrukcji, zastosowanych materiałów i przeprowadzonej obróbki powierzchniowej elementów pary. Celem badań było wyznaczenie wpływu modyfikacji warstwy powierzchniowej elementów stalowych borem w parach pracujących w warunkach tarcia ślizgowego. Badania porównawcze przeprowadzono na testerze T-05 typu rolka–klocek. W celu realizacji programu badań wykonano próbki pierścieniowe z trzech gatunków stali: 38CrAlMo5-10, 46Cr2 i 30MnB4. Próbki te azotowano jonowo, borowano w proszku, borowano laserowo oraz metodą PVD wykonano powłokę TiB2. Próbki pierścieniowe skojarzone zostały w warunkach testu z przeciwpróbkami wykonanymi ze stopu łożyskowego AlSn20, a obszar tarcia smarowano olejem silnikowym Lotos mineralny 15W/40. Przeprowadzone badania wykazały, że warstwy powierzchniowe borowane w proszku wpływają na obniżenie współczynnika tarcia podczas rozruchu, a jego maksymalne wartości są zbliżone do zmierzonych w skojarzeniach z warstwami azotowanymi i ulepszanymi cieplnie ze stali 30MnB4. Największe wartości współczynnika tarcia i najwyższe temperatury w obszarze tarcia występują w parach z próbkami pierścieniowymi z warstwą borowaną laserowo i z powłoką TiB2. Zużycie stopu łożyskowego AlSn20 jest największe w skojarzeniu z przeciwpróbką z powłoką TiB2, a najniższe zużycie zmierzono w skojarzeniach z warstwami azotowanymi i ulepszanymi cieplnie.
The properties of the frictional slide couplings depend on the constructional material used and technology applied during the production process. The tribological properties of the frictional coupling are the resultant of the coupling construction and properties of the cooperating surfaces. The surface layer may be shaped by technological processes through the correct material selection used for these elements and technology applied for the surface treatment. Currently, numerous methods are used in producing the surface layers, which protect against tribological wear; however, particularly advantageous properties feature those coatings with boron. These coatings feature a high degree of the hardness of the structures, resistance to wear and corrosion, and good fatigue properties, depending on the technological preparation of the base. The purpose of the study to determine the influence of the boron modification of the technological surface layer on the characterisation of the operation of frictional pairs under the conditions of mixed friction, and in practical application, increasing of the durability and reliability of frictional pairs and, in consequence, whole technical objects, such as automobiles. In order to create surface layers modified with boron, technological processes were selected that allowed for the creation of these layers on the elements of a combustion engine. These processes were used for the treatment of the surface layer of annular samples for stand test on the T-05 block-on-ring wear tester. Three types of steel were used in the creation of annular samples, 38CrAlMo5-10, 46Cr2, and 30MnB4. Samples from 38CrAlMo5-10 steel were nitrided in the atmosphere H2 + N2, at the temperature of 500°C for 6 hours. Samples from 46Cr2 steel were borided in powder, at the temperature of 950°C for 8 hours. In the boronizing process, powder of the following composition was used: B4C-30%, Al2O3-68%, NH4Cl and NaF. Samples from 46Cr2 steel were also laser-borided, with the use of CO2 laser (power of beam P = 2 kW, spot diameter d = 4 mm, energy density 160 W/mm2, tracking speed v = 16 mm/s, gas carrier –argon). The boronizing process consisted in covering the annular sample with the layer of amorphous boron and liquid glass and melting with a laser beam. Also, the samples from steel 46Cr2 were covered with a TiB2 coating, using the PVD method (temperature 400°C, time 40 min, pressure in ionization chamber p = 2,5 x 10-2 bara). The sample of 30MnB4 steel was hardened and tempered, and hardening was at the temperature of 800°C, and drawing temper was at the temperature of 450°C. Modified surface layers of annular samples were matched under test conditions with counter samples made from AlSn20 bearing alloys. Tested slide pairs were lubricated during the stand test with 15W/40 Lotos mineral engine oil. On the basis of the tests and the analysis of the results, it was concluded that the boron-modified surface layers can be applicable in the slide couplings operating under mixed friction conditions, and their tribological properties are the effect of the interaction between the surface layers of the slide coupling elements and the lubricating oil. The modified surface layer in the process of boronizing in powder coupled with the AlSn20 bearing alloy is characterised by low friction resistance and temperature, which ensures that the slide coupling has conducive conditions for start-up and fast stabilisation of the friction conditions. In turn, the laser borided surface layer and layer TiB2 causes intensive friction processes in the slide coupling, which generates high friction resistance and temperature and intensifies the processes of bearing alloy wear. It was stated that the use of 30MnB4 steel in the slide coupling after the hardening and tempering ensures similar work parameters and a comparable level of wear of the bearing alloy, as in the application of 38CrAlMo5-10 steel with a nitrided surface. The research proved that the lubrication of the friction area with the mineral oil has an influence on the decrease of wear of the bearing alloy and the decrease of the matching parameters of the moment of friction and temperature, mainly in the couplings with the AlSn20 alloy counter samples. Using the boron-modification processes of surface layers in slide couplings operating under the conditions of mixed friction, it is possible to decrease the costs of material using mild-alloy steel or carbon steel and to decrease the costs of exploitation by increasing the durability of elements. However, each time surface layers with boron are used on a large scale, it should be preceded by economic calculation.
Źródło:
Tribologia; 2009, 1; 97-112
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sravnenije koehfficientov trenija skol'zhenija semjan i zhmykha l'na po poverkhnostjakh razlichnykh materiallov
Comparison of the sliding friction coefficient of linseed of oil varieties and linseed oil cake over the surface of different metals
Autorzy:
Kuzminskijj, R.
Sokolovskijj, O.
Vasilkevych, V.
Sheremeta, R.
Powiązania:
https://bibliotekanauki.pl/articles/77520.pdf
Data publikacji:
2015
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
sliding friction
linseed oil
flax seed
dry friction
friction coefficient
metal surface
Źródło:
Motrol. Motoryzacja i Energetyka Rolnictwa; 2015, 17, 4
1730-8658
Pojawia się w:
Motrol. Motoryzacja i Energetyka Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł

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