Wyniki wyszukiwania - BazTech

1

The tribological characteristics of zirconium diboride particle reinforced composites processed by SPS

Sulima Iwona, Hyjek Paweł

Composites Theory and Practice

|

2024

|

R. 24, nr 1

2--8

EN

The tribological properties of composites based on 316L steel reinforced with zirconium diboride (5 and 10 wt.%) were described. The composites were fabricated by the spark plasma sintering (SPS) method. Wear resistance tests were carried out using the ball-on-disc method at room temperature under dry friction conditions. Countersamples made of SiC, Si3N4, ZrO2 and AISI52100 steel were used in the tests. The determined parameters included the coefficient of friction μ, mass loss m and specific wear rate Ws(disc). After the tribological tests, the surfaces of the samples were examined under a confocal microscope. The obtained research results showed that the tribological properties depend on the test conditions (the type of countersample) and on the content of the ZrB2 reinforcing phase.

PL

Przedstawiono właściwości tribologiczne kompozytow na osnowie stali 316L wzmocnionych diborkiem cyrkonu (5 i 10% wag.). Kompozyty zostały wytworzone z zastosowaniem metody Spark Plasma Sintering (SPS). Badania odporności na zużycie przeprowadzono, wykorzystując metodę ball-on-disc w temperaturze pokojowej w warunkach tarcia suchego. Testy przeprowadzono, stosując następujące przeciwprobki: SiC, Si3N4, ZrO2 i stal AISI52100. Wyznaczono współczynnik tarcia μ, ubytek masy m i wskaźnik zużycia Ws(disc). Powierzchnie probek po testach tribologicznych obserwowano za pomocą mikroskopu konfokalnego. Uzyskane wyniki badań wykazały, że właściwości tribologiczne zależą od warunkow badań (rodzaju przeciwprobki) i ilość fazy wzmacnianej ZrB2.

2

The effect of NI-TIO2 and NI-TIO2-graphene coatings and heat treatment hardening on solid particles erosion resistance of grade 410 stainless steel

Khalid Wissam, Al-Tameemi Hamza A.

Engineering Transactions

|

2023

|

Vol. 71, iss. 4

571--593

3

Wear performance of Ti-6Al-4 V titanium alloy through nano-doped lubricants

Etri Hamza E. L., Singla Anil Kumar, Özdemir Mehmet Tayyip, Korkmaz Mehmet Erdi, Demirsöz Recep, Gupta Munish Kumar, Krolczyk J. B., Ross Nimel Sworna

Archives of Civil and Mechanical Engineering

|

2023

|

Vol. 23, no. 3

art. no. e147, 2023

EN

Titanium and its alloys are widely utilized in the biomedical sector, they still exhibit poor tribological properties and low wear resistance when employed against even weaker substances. The poor hardness, instability, high coefficient of friction, low load-carrying capacity, and insufficient resistance to not only abrasive but also adhesive wear are further disadvantages of titanium alloys. The focus of this investigation is on the tribological performance of Ti-6Al-4 V alloy in contact with WC carbide abrasive balls when subjected to nanodoped cooling and lubrication conditions. Tribological experiments were executed on Ti-6Al-4 V flat samples using a ball-on-flat tribometer in dry hybrid graphene/boron nitride combination nanoparticles (MQL, nano-3), nanographene with MQL (nano-1), and boron nitride with MQL (nano-2) conditions. After that, the most significant tribological characteristics were investigated, including volume loss, friction coefficient, wear rate, and micrographic structures. The outcomes also demonstrated that the hybrid nanoparticle situation experienced the least amount of volume loss.

4

Synthesis and Characterization of Bioceramics Reinforced Aluminium Matrix Composites

Bhuvaneswari V., Rajeshkumar L., Saravanakumar R., Balaji D.

Archives of Metallurgy and Materials

|

2022

|

Vol. 67, iss. 4

1217--1226

EN

Current work attempts to fabricate aluminium alloy AA2219 metal matrix composite (AMC) reinforced with natural bio-based sea shell powder (SSP) which is a ceramic material, in view of improving the mechanical and tribological properties. SSP was characterized by X-Ray Diffraction (XRD) to assess its chemical constituents and particle size. Stir casting route was adopted for fabricating AMCs reinforced with 1, 2 and 3 wt.% of SSP. Energy Dispersive X-ray Spectroscopy (EDS) was used to analyse the formation of secondary elements during casting and scanning electron microscopy (SEM) was used analyze the surface morphology of the composite specimen before and after tribological tests. Hardness, Compressive strength and tribological properties were evaluated using appropriate tests and corresponding ASTM standards. Characterization methods revealed that the formation of secondary elements was very low at 3 wt.% of SSP when compared with other compositions. Hardness and compressive strength was found to be maximum for 3 wt.% of SSP while the specific wear rate and coefficient of friction values were found to be lesser for the same composite when compared with the unreinforced alloy and were on par with the AA2219 composites containing synthetic reinforcements.

5

Effect of Water Absorption on Tribological Properties of Thermoplastics Matrix Composites Reinforced with Glass Fibres

Walczak Mariusz, Szala Mirosław, Pieniak Daniel

Advances in Science and Technology. Research Journal

|

2022

|

Vol. 16, no 2

232--239

EN

The present work investigated the water absorption of thermoplastic matrix composites and their effect on tribological behaviour. Four thermoplastic composites were researched based on Polyamide 6 and Polyamide 66 matrix reinforced with glass fibres. The composites fabricated using the injection moulding technique were immersed in distilled water at room temperature for a water absorption test for 14 days. Dry sliding wear was conducted using a pin-on-disc trbiotester. The coefficient of friction (COF) and the wear rate (K) was determined. The sliding trace was analyzed using a scanning electron microscope (SEM) to reveal the sliding wear mechanism of composites. Studies have shown that polyamide PA6 based composites are less prone to absorb water than PA66 matrix. In addition, the composites richer in fibreglass exhibit lower water absorption. Tribological results indicated that polymer composites showed higher COF and K after water absorption testing. Mean COF and K were in the range of 0.071÷0.321 and 2.51∙10-6÷1.81∙10-4 mm3N-1m-1, respectively. Wear traces SEM analysis revealed that untreated samples are characterized by less intense abrasive and adhesive wear mode than the hydrated polymers. Besides, the degradation process took place primarily at the polymer matrix-fibreglass interfaces.

6

Microstructure, tribological performances, and wear mechanisms of laser-cladded TiC-reinforced NiMo coatings under grease-lubrication condition

Weixin Zhu, Dejun Kong

Materials Science Poland

|

2021

|

Vol. 39, No. 3

395--409

EN

NiMo-5%TiC, NiMo-15%TiC, and NiMo-25%TiC coatings were prepared on GCr15 steel by laser cladding (LC). The microstructure and the phases of the obtained coatings were analyzed using ultra-depth-of-field microscopy (UDFM) and X-ray diffraction (XRD), respectively. A ball-on-disk wear test was used to analyze the friction-wear performance of the substrate and the NiMo-TiC coatings under grease-lubrication condition. The results show that the grain shape of NiMo-TiC coatings is dendritic. The wear resistance of NiMo-TiC coatings is improved by the addition of TiC, and the depths of the worn tracks on the substrate and on the NiMo-5%TiC, NiMo-15%TiC, and NiMo-25%TiC coatings are 4.183 μm, 2.164 μm, 1.882 μm, and 1.246 μm, respectively, and the corresponding wear rates are 72.25 μm3/s/N, 32.00 μm3/s/N, 18.10 μm3/s/N, and 7.99 μm3/s/N, respectively; this shows that the NiMo-25%TiC coating has the highest wear resistance among the three kinds of coatings. The wear mechanism of NiMo-TiC coatings is abrasive wear, and the addition of TiC plays a role in resisting wear during the friction process.

7

Diagnostics of the excessive wear of the machine on a model of developmental, progressive interactions between diagnostic signals and rotation speed signals

Lindstedt Paweł, Rokicki Edward, Deliś Maciej, Dobosz Kamila, Czarnecki Andrzej

Journal of KONBiN

|

2021

|

Vol. 51, iss. 4

107--141

EN

In the machine operating process, there are certain interactions between its operational use and wear. The current wear is increased by the current intensity of operational use, and usable potential is reduced by the current wear rate. In the diagnostic inference process, static characteristics and trajectories of state from the experiment are compared with different matrices determined for various assumed configurations of changes. As a result, the approximated diagnosis is created. This method is not universal. It applies only to the continuous progressive state, more or less increased wear rate of the machine.

PL

W procesie eksploatacji maszyny występują interakcje między jej użytkowaniem a użyciem. Aktualne zużycie powiększone jest aktualną intensywnością użytkowania, a potencjał użytkowy jest pomniejszany aktualnym stanem zużycia. W procesie wnioskowania diagnostycznego charakterystyki statyczne i trajektorie stanu z eksperymentu porównuje się z różnymi matrycami wyznaczonymi dla różnych założonych konfiguracji zmian. Efektem tego postępowania jest przybliżona diagnoza. Metoda nie jest uniwersalna. Dotyczy tylko stanu ciągłego, postępującego, mniej lub bardziej wzmożonego zużywania się maszyny.

8

Modelling and optimization of wear parameters of Al 4032 reinforced with coal ash using Taguchi and RSM approach

Gudimetla Avinash, Lingaraju Dumpla, Sambhu Prasad S.

Composites Theory and Practice

|

2021

|

R. 21, nr 1-2

3--11

EN

The present study aimed to analyze the wear behaviour of composites synthesized by reinforcing Al 4032 with 2, 4, 6 wt.% of coal ash using the stir casting technique. Wear testing was performed on the composites at room temperature in the absence of lubrication using a pin-on-disc tribometer considering the process parameters as wt.% of reinforcement, speed and load. Micro structural characterization using scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX) was performed on the cast composites to ascertain the existence of the reinforcement along with its distribution in the prepared composites. The Taguchi L16 orthogonal array was utilized to design experiments to study the significance of the process parameters on the wear rate. A mathematical model was developed for the wear rate using response surface methodology (RSM). 6 wt.% reinforcement, at the speed of 100 rpm and 10 N load were the obtained optimized parameters for the minimum wear rate. Surface plots as well as contour plots were analyzed to understand the consequence of the process parameters on the wear rate. The analysis of variance (ANOVA) revealed that speed with 76.10 % was the most prominent parameter followed by load and reinforcement with 11.23 and 9.42% respectively.

9

Investigation of mechanical and tribological behavior of Al 4032-SiHGM MMC

Gudimetla Avinash, Lingaraju D., Prasad S. Sambhu

Composites Theory and Practice

|

2020

|

R. 20, nr 3-4

142--156

EN

The present study is aimed at identifying the influence of silicon hollow glass microspheres (SiHGM) on a newly engineered metal matrix composite. Silicon micro balloons of various wt.% (2, 4, 6) are reinforced in to aluminium 4032 to produce a composite using the stir casting technique. The mechanical properties of the composite such as hardness, tensile and compressive strength were measured. The dry sliding wear test was conducted on the produced specimens to measure the wear rate and coefficient of friction. The results revealed that the properties of the composite are better with an increase in the wt.% of reinforcement. The presence of reinforcement in the composites was identified using Energy Dispersive X-Ray analysis (EDX). The grain boundaries and grain refinement for various compositions of reinforcements and worn surfaces were analyzed using Scanning Electron Microscope (SEM) micrographs. The process parameters for the minimum wear rate and coefficient of friction were identified and optimized by using the Taguchi L16 orthogonal array. Analysis of variance (ANOVA) was used to determine the percentage contribution of each process parameter. Multi-response optimization was carried out using Grey relational analysis (GRA) to optimize the process parameters to attain a minimum coefficient of friction and wear rate. The variation in wear rate and coefficient of friction are analyzed with respect to reinforcement (wt.%), speed (rpm) and load (N).

10

Mechanical and Tribological Analysis of Monolith and Coating Polyetheretherketone

Otto Mateusz, Zimowski Sławomir, Sikora Wojciech, Moskalewicz Tomasz

Tribologia

|

2019

|

nr 4

73--86

PL

W pracy dokonano analizy porównawczej właściwości mikromechanicznych oraz tribologicznych polieteroeteroketonu (PEEK) w postaci monolitycznej i powłoki. Powłoka PEEK 708 została osadzona metodą elektroforezy na płaskim podłożu ze stopu tytanu. Właściwości mikromechaniczne zostały zbadane metodą indentacyjną przy użyciu wgłębnika Vickersa oraz w teście zarysowania. Na podstawie badań wyznaczono twardość Vickersa (HV), moduł sprężystości (E), twardość zarysowania (HS) oraz odporność na mikrouszkodzenia (MMR). Właściwości tribologiczne zdefiniowano poprzez współczynnik tarcia (fs i fw), który wyznaczono zarówno w teście zarysowania oraz podczas tarcia w układzie typu kula–tarcza. Wyniki badań wskazują, że pomimo niedużo większej twardości Vickers’a (HV) powłoki PEEK 708 (HV = 350 MPa, HS = 300 MPa) względem monolitycznego PEEK (HV = 300 MPa, HS = 210 MPa), występuje niemal 40% różnica w ich twardościach zarysowania (HS). Z przeprowadzonej analizy wynika, że metody wyznaczania parametrów mikromechanicznych oraz tribologicznych stosowane dla materiałów monolitycznych PEEK sprawdzają się w badaniach powłok polimerowych PEEK. W określonych warunkach badań nie stwierdzono wpływu materiału podłoża na otrzymane wyniki dla powłoki PEEK 708.

EN

In this work, a comparative analysis of the micromechanical and tribological properties of polyetheretherketone (PEEK) in bulk and coating form was performed. The PEEK 708 coating was applied on a Ti6Al4V titanium alloy flat specimen using the electrophoretic deposition method. The micromechanical properties were determined through indentation tests performed using the Vickers method and scratch tests. Based on research work, the Vickers hardness (HV), elastic modulus (E), scratch hardness (HS), and Micro Mar Resistance (MMR) were determined. The tribological properties were defined by the coefficient of friction (fs and fw), which was obtained in scratch tests and ball-on-disk tests. The results of this research indicate, despite the slightly higher Vickers hardness (HV) of the PEEK 708 coating (HV = 350 MPa, HS = 300 MPa) relative to PEEK bulk (HV = 300 MPa, HS = 210 MPa), that there is an almost 40% difference between the scratch hardness (HS) values of these PEEK forms. It appears from the result analysis in this paper that testing methods to determine the micromechanical and tribological properties of PEEK in monolith form can be used for both PEEK coatings. Under certain test conditions, the impact of the substrate properties on the results of the PEEK 708 coating was not found.

11

Synthesis and characterization of AA5083 and AA2024 reinforced with SiO2 particles

Raja R., Jannet S., Thampy M. A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

|

2018

|

Vol. 66, nr 2

127--132

EN

Among the types of different particulates, silica is a standout as one of the the cheapest and low-density particulates accessible in substantial amounts. The present study has been centered around the synthesis and study of aluminum matrix composite strengthened with nano-sized SiO2 particles of various weight percentage by means of the stir casting technique. The EDX emphasized the presence of various elements and augmented the in situ reaction. The tensile strength and wear studies were also carried out. The reinforcement materials percentage variation was one of the important factors for the present studies. The Aluminum Alloy 5083 and 2024, which are magnesium and copper-based alloys, had a significant effect on the material characterization.

12

Mechanical properties of Si3N4 – graphene composites sintered by SPS method

Klimczyk P., Jaworska L., Cygan S., Morgiel J., Major Ł., Olszyna A.

Prace Instytutu Odlewnictwa

|

2017

|

Vol. 57, no. 4

235--239

EN

Silicon nitride powder with a small addition of magnesium oxide and yttria stabilized tetragonal zirconia fine particles was used as a starting material. Multilayer graphene nanoplatelets were used as filler for silicon nitride based composites. Graphene content in the mixtures was 0‒2 wt. %. The composites were obtained by the Spark Plasma Sintering method at 1650°C under 35 MPa of uniaxial pressure. Separation of the agglomerated graphene platelets in the matrix was observed for these materials. Insufficient dispersity of graphene slightly decreased the mechanical properties of Si3N4 ceramics. The SEM and TEM microstructural analysis of sintered materials show that the applied pressure during the sintering process leads to the orientation of the graphene phase and in consequence causes anisotropy of properties. The differences of friction coefficients were examined with the Ball-on-Disc method for the two directions (parallel and perpendicular to the pressing axis). Also the specific wear rate of the ball for the direction parallel to pressing axis differ significantly in comparison to the wear for the direction perpendicular to the pressing direction.

13

Effect of test conditions on wear properties of steel-matrix composites

Sulima I., Hyjek P.

Metallurgy and Foundry Engineering

|

2017

|

Vol. 43, no. 4

269--279

EN

The friction coefficient and wear behavior of 316L austenitic stainless steel and 316L steel + 8vol% TiB2 + 1vol% B composites were investigated within a temperature range of 20°C to 800°C. The materials were prepared by the powder metallurgy method. The wear behavior was studied by using a ball-on-disc wear tester at room temperature. The surface before and after wear tests was analyzed using scanning electron microscopy (SEM). The results indicated that the friction coefficient and wear resistance of stel-8TiB2-1B composites depend on the wear test conditions.

PL

W pracy określono współczynnik tarcia i odporność na zużycie dla stali austenitycznej 316L i kompozytów o osnowie stalowej zawierających 8% obj. TiB2 i 1% obj. B. Materiały do badań wytworzono z wykorzystaniem metody metalurgii proszków. Badania właściwości tribologicznych przeprowadzono, stosując metodę ball-on-disk w zakresie temperatury 20–800°C. Badania mikrostrukturalne przed testami i po testach ścierania przeprowadzono przy zastosowaniu skaningowej mikroskopii elektronowej (SEM). Wyniki wykazały, że współczynnik tarcia i odporność na zużycie zależą od warunków testów ścierania (temperatury).

14

Resource evaluation of friction pair “contact wire – contact strip”

Antonov A. V., Sychenko V. G.

Archives of Transport

|

2017

|

Vol. 44, iss. 4

7--14

EN

Purpose. Investigate the impact of current collection system parameters and external factors on the resource of friction pair “contact wire – contact strip”. Relevance. The level of electrified railways reliability depends on the reliability and durability of the individual objects of power supply system and the locomotive facilities, in turn, the current collection quality depends on design of contact network and pantographs, contact wires materials, contact strips and external influencing factors. The resource system “contact wire – contact strip” is an important technical and economic characteristics, and its average actual resource is much less established. It means that the actual resource does not reach the optimum value from an economic point. Increasing velocity of the electric rolling stock exacerbates the problem of improving the current collection quality, becomes an actual task of increasing the resource friction pair “ contact wire – contact strip” for mainline railways. Scientific novelty. This work determined the influence structural parameters of the friction pair, the current collection system parameters and external factors on the wear rate of the friction pair “contact wire – contact strip”. Proposed to create a predictive mathematical model that uses the dependence of the influencing parameters obtained in this work to assess the wear and resource of contact wire and contact strips. Practical importance. Developed the device for wear researching of friction pairs in laboratory conditions allows assessing the wear rate of the system “contact wire – contact strip” and their residual resource at different combinations of the friction pair and external factors. The obtained results allow us to construct a predictive mathematical model to evaluate wear rate of the elements of the friction pair “contact wire – contact strip” and identify their residual resource.

15

Powłoki dla ochrony przed zużyciem elementów maszyn i urządzeń

Morel S.

Przegląd Spawalnictwa

|

2015

|

R. 87, nr 9

65--69

PL

Dokonano analizy przyczyn zużycia maszyn i urządzeń oraz przedstawiono możliwości ograniczania zużywania się elementów poprzez wytwarzanie na ich powierzchniach plazmowo natryskiwanych powłok z mieszanin najtwardszych materiałów z miękką fazą wiążącą, tworzącą metalurgiczne połączenie z podłożem. Przeprowadzono pomiary mikrotwardości oraz odporności na zużycie ścierne i erozyjne wytypowanych powłok ceramicznych i cermetalowych Uzyskane wyniki porównano z wynikami ścierania stalowych próbek - uzyskując dla powłok znaczący wzrost odporności. Wytypowanymi powłokami natryskano elementy maszyn i urządzeń, poddano je eksploatacji przemysłowej. Uzyskane wyniki uzasadniają celowość wytwarzania powłok na elementach maszyn i urządzeń.

EN

The mechanism is described of corrosive processes occurring on the heated walls of boilers, both at low temperatures, i.e. in the furnace zone, and at medium temperatures, i.e. on the steam superheater surfaces. Further part of the work analyzes the processes of pitting corrosion occurring in the presence of the oxides of nitrogen, sulfur, and chlorine, which dissolve in water vapour condensing on the metal walls of heat equipment under the furnace lining. Moreover, the causes of the erosive wear of heat equipment walls are described. The examination were carried out of the properties of plasma sprayed ceramic and cermet coatings that are marked by the ability of forming a tight barrier impermeable to corrosive agents. The measurements were made, including porosity, erosive wear resistance, and the ability of reducing steel substrate corrosion. Based on the results obtained, the evaluation was performed of the usefulness of coatings for reducing the wear processes of heat equipment metal walls. Results from the industrial operation of elements with protective coatings are reported.

16

The influence of equilibrium quality parameters of a surface layer on the wear resistance of parts

Bezjazychnyj V. F., Sutyagin A. N.

Tribologia

|

2014

|

nr 5

35--43

EN

The article describes the processes of hardening and softening of the surface layer of parts in the process of wear during the formation of the equilibrium state of work surfaces of friction units. Based on the energy approach to the problem of the determination of the relationship of the wear rate of the contacting surfaces of machine parts with the quality parameters of the surface layer, the equation for the calculation of the linear wear rate in the equilibrium state is shown. The equation contains the following variables of basic surface quality parameters: the roughness parameter, the degree of hardening of the surface layer, operating stresses in the surface layer of machine parts, and the depth of hardening. The possibility of determining the relationship of the wear rate with the technological conditions of machining is shown.

PL

W artykule opisano proces utwardzania i odpuszczania warstwy wierzchniej elementów w procesie tarcia podczas tworzenia się stanu równowagi powierzchni roboczych elementów trących. Bazując na podejściu energetycznym do problemu określenia zależności pomiędzy intensywnością zużywania współpracujących powierzchni a jakością warstwy wierzchniej, zaprezentowano równanie dla obliczania liniowej intensywności zużywania w stanie równowagi. Równanie zawiera następujące zmienne charakteryzujące jakość powierzchni: parametr chropowatości, stopień zgniotu warstwy wierzchniej, występujące naprężenia w warstwie wierzchniej obrabianych materiałów i głębokość zgniotu. W pracy została zaprezentowana możliwość określenia zależności intensywności zużywania od parametrów technologicznych obróbki.

17

Tribological Properties of Steel/TiB2 Composites Prepared by Spark Plasma Sintering

Sulima I.

Archives of Metallurgy and Materials

|

2014

|

Vol. 59, iss. 4

1263--1268

EN

The mechanical and tribological properties of sintered 316L stainless steel composites with TiB2 submicroparticles were investigated. The composites were manufactured by Spark Plasma Sintering (SPS). The wear behaviour was studied by using a ball-on-disc wear tester at room temperature. The worn surface were analysed using Scanning Electron Microscopy (SEM). The results indicated that the friction coefficient and the wear resistance of composites with the same content of TiB2 particles depend on the sintering conditions.

PL

W prezentowanej pracy zbadano właściwości mechaniczne oraz tribologiczne materiałów kompozytowych umacnianych submikroczątkami ceramiki TiB2. Do wytworzenia spieków kompozytowych zastosowano plazmowe spiekanie iskrą elektryczną (SPS). Badania właściwosci tribologicznych przeprowadzono w temperaturze pokojowej w układzie ball-on-disc. Powierzchnie próbek po testach ścierania obserwowano za pomocą skaningowej mikroskopii elektronowej. Uzyskane wyniki badań wykazały, że właściwości tribologiczne zależą od warunków spiekania dla kompozytów zawierających taką samą ilość ceramiki TiB2.

18

Effect of TiB2 content and temperature on sliding wear behavior of AA7075/TiB2 in situ aluminum cast composite

Michael Rajan H. B., Ramabalan S., Dinaharan I., Vijay S. J.

Archives of Civil and Mechanical Engineering

|

2014

|

Vol. 14, no. 1

72--79

EN

Aluminum alloy AA7075 reinforced TiB2 particulate composites were prepared by the in situ reaction of K2TiF6 and KBF4 to molten aluminum. The prepared aluminum matrix composites (AMCs) were characterized using X-ray diffraction and scanning electron microscopy (SEM). The sliding wear behavior of the AMCs was evaluated using a pin-on-disc wear apparatus. The effect of TiB2 particulate content (0, 3, 6 and 9 wt%) and temperature (30, 60, 90, 120, 150, 180, 210 and 240 °C) on wear rate and worn surface of the AMCs were studied. The results indicated that TiB2 particles were effective to enhance the wear resistance of the AMCs at all test temperatures studied in this work. The wear rate of the AMCs increased when the applied temperature was increased. The in situ formed TiB2 particles pushed the transition wear temperature by another 30 °C. The wear mode was observed to be abrasive at room temperature and metal flow at high temperature.

19

Test Rigs for the Investigations of Dry and Fluid Friction

Strzelecki S., Wójcicki R.

Machine Dynamics Research

|

2010

|

Vol. 34, No. 1

101-109

EN

This paper presents the electronically controlled and heavy duty, industrial MAN type of test rigs for the investigation into the friction phenomena, friction coefficient and the wear of different materials. Exemplary results of the tribological characteristic such as the friction type, friction coefficient and wear rate of contacting materials are included. MAN test rig allows carrying the experiments on the heavy loaded contacts of tribo-materials.

20

The Tribological Properties of High Speed Steel based Composites

Madej M.

Archives of Metallurgy and Materials

|

2010

|

Vol. 55, iss. 1

61-68

EN

Attempts have been madę to describe the influence of the production process parameters and additions of powders, such as: copper, graphite, iron and tungsten carbide, on tribological properties of copper infiltrated HSS based composites. The powder compositions used to produce skeletons for further infiltration were M3/2, M3/2+20%Fe, M3/2+50%Fe M3/2+7.5%Cu and M3/2+0,3%C The powders were cold pressed at 800 MPa. The infiltration process was carried out in vacuum. Both green compacts and preforms sintered for 60 minutes at 1150°C in vacuum were contact infiltrated with copper to yield finał densities exceeding 97% of the theoretical value. The as-infiltrated composites were tested for Brinell hardness and bending strength, and subjected to wear tests performed by block-on-ring wear tester. From the analysis of the obtained results it has been found that the mechanical properties are mainly affected by the manufacturing route and composition of porous skeletons used for infiltration. Considerable differences in hardness between materials obtained from the two infiltration routes have been observed, with lower wear rates achieved after direct infiltration of green compacts.

PL

Kompozyty na osnowie stali szybkotnących to materiały odznaczające się dużą odpornością na zużycie cierne, wynikającą przede wszystkim z odporności na zużycie cierne stali szybkotnącej tworzącej osnowę kompozytów. Poszukiwanie sposobu obniżenia kosztów wytwarzania stali szybkotnących oraz kompozytów na osnowie stali szybkotnącej polega na zastosowaniu procesu infiltracji do wytwarzania kompozytów na osnowie stali szybkotnącej z dodatkiem miedzi, gdzie jako porowate kształtki do infiltracji stosowane są wypraski lub spieki ze stali szybkotnącej lub stali szybkotnącej z dodatkami. Przedstawiono wyniki badań w zakresie badania odporności na zużycie cierne i współczynnika tarcia infiltrowanych kompozytów na osnowie stali szybkotnącej. Materiał badawczy stanowiły kształtki ze stali szybkotnącej gatunku M3/2 i M3/2+20%Fe, M3/2+50%Fe, M3/2+7,5%Cu, M3/2+0,3%C. Porowate kształtki przeznaczone do infiltracji prasowano pod ciśnieniem 800 MPa, część z nich poddano spiekaniu w piecu próżniowym w temperaturze 1150°C przez 60 minut. Następnie porowate kształtki infiltrowano miedzią, metodą nakładkową w piecu próżniowym w temperaturze 1150°C przez 15 minut. Badania odporności na zużycie cierne oraz współczynnika tarcia przeprowadzono testerem T-05. Testy prowadzono przy ruchu postępowym w styku ślizgowym suchym, bez udziału środków smarujących. Techniką infiltracji miedzi do porowatych wyprasek i spieków ze stali szybkotnącej M3/2 oraz stali szybkotnącej M3 z dodatkami stopowymi można uzyskać kompozyty o gęstości zbliżonej do gęstości teoretycznej, sięgającej 97,0%. Własności otrzymanych kompozytów zależą od zastosowanych dodatków stopowych oraz od technologii ich wytwarzania. Odporność na zużycie cierne jest charakteryzowana przez ubytek masy poszczególnych kompozytów. Analizując wyniki testu można stwierdzić, że poza kompozytami M3/2+7,5%Cu i M3/2+0,3%C większą odpornością na zużycie cierne charakteryzują się infiltrowane wypraski. Dodatek 20% lub 50% żelaza nie powoduje obniżenia odporności na zużycie cierne infiltrowanych wyprasek w określonych warunkach procesu tarcia.