scholarly journals Tribological Behaviour of Co-W Under Dry and Lubricanting Conditions

2015 ◽  
Author(s):  
N. Tsyntsaru
Keyword(s):  
Wear Resistance ◽  
Solid Lubricant ◽  
Wear Volume ◽  
Tribological Behaviour ◽  
Tungsten Alloys ◽  
Dry Conditions ◽  
New Type ◽  
The Given ◽  
Steel St3

The dry and lubricating wear was investigated for steel and Co-W samples in the view of revealing the best performance of tungsten alloys. The tribological behaviour was studied under bi-directional ball-on-flat sliding tests: 10 N and 50 000 cycles. The given research identified that Co-W coatings have superior wear resistance than those of uncoated samples (steel ST3) under dry and also under lubricating conditions. Thus, wear volume of Co-W samples is decreasing two times under dry conditions and ten times under lubricating conditions. The use of new type of solid lubricant (sugar film) is discussed.

scholarly journals Effect of Bulk Current Density on Tribological Properties of Fe-W, Co-W and Ni-W Coatings

2015 ◽  
Author(s):  
S.A. Silkin ◽  
A.V. Gotelyak ◽  
N. Tsyntsaru ◽  
A.I. Dikusar ◽  
R. Kreivaitis ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Current Density ◽  
Dry Friction ◽  
Scratch Test ◽  
Tribological Behaviour ◽  
The Coefficient Of Friction ◽  
Current Densities ◽  
Scratch Tests ◽  
The Given

Evaluation of tribological behaviour of Fe-W, Ni-W and Co-W coatings produced by electrodeposition at various bulk current densities (BCD) was under investigation in the given study. BCD does not have essential effect on the microhardness and wear characteristics of Fe-W and Co-W coatings. But the scratch tests reveal the presence of such influence. These tests showed superior wear resistance for the coatings obtained at low BCD. It was found that BCD has influence on wear resistance of Ni-W coatings under dry friction conditions. The BCD also has an influence on the coefficient of friction of Fe-W and Ni-W coatings at dry friction conditions. However, such an effect is opposite to that, observed at the scratch test.

Investigation on Wear Behavior of Electrostatic Micro-Solid Lubricant Coatings Under Dry Sliding Conditions

2012 ◽  
Author(s):  
UmaMaheshwera Reddy Paturi ◽  
Narala Suresh Kumar Reddy
Keyword(s):  
Wear Resistance ◽  
Solid Lubricant ◽  
Wear Behavior ◽  
Spray Coating ◽  
Solid Lubricants ◽  
Dry Sliding Wear ◽  
Wear Volume ◽  
Dry Sliding ◽  
Molybdenum Disulphide ◽  
Aluminum Specimen

Dry sliding experiences high friction and wear thus influencing the life and quality of the parts under sliding. To provide low friction and improve wear resistance, solid lubricants have an edge over conventional choice. This article features a specific study of the application of solid lubricant in dry sliding operations and presents its influence on wear resistance. Using a pin-on-disc tribometer designed according to ASTM G99 standard, dry sliding wear tests on aluminum alloy AA6351-T6 specimens were performed against uncoated EN31 steel and molybdenum disulphide (MoS2) coated EN31 steel discs. In this study, counter surfaces (discs) were coated with micron sized MoS2 solid lubricant powder particles using electrostatic spray coating (ESC) method. The best results for wear volume and friction coefficient (minimum values) were registered when aluminum specimen slid against MoS2 coated EN31 steel. Outcome of this study shows that the presence of solid lubricant film on disc specimen will greatly influence the sliding performance of pin material in lubricating and preventing wear through reduction in the frictional force due to presence of lamellar structure as a transfer film and favorable change in sliding interaction.

scholarly journals Automatic speech segmentation using throat-acoustic correlation coefficients

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Rustam Rafikovich Mussabayev ◽  
Maksat N. Kalimoldayev ◽  
Yedilkhan N. Amirgaliyev ◽  
Timur R. Mussabayev
Keyword(s):  
Large Volume ◽  
Automatic Segmentation ◽  
Correlation Coefficients ◽  
High Accuracy ◽  
Speech Segmentation ◽  
Preliminary Training ◽  
Effi Ciency ◽  
Segmentation Accuracy ◽  
New Type ◽  
The Given

Abstract This work considers one of the approaches to the solution of the task of discrete speech signal automatic segmentation. The aim of this work is to construct such an algorithm which should meet the following requirements: segmentation of a signal into acoustically homogeneous segments, high accuracy and segmentation speed, unambiguity and reproducibility of segmentation results, lack of necessity of preliminary training with the use of a special set consisting of manually segmented signals. Development of the algorithm which corresponds to the given requirements was conditioned by the necessity of formation of automatically segmented speech databases that have a large volume. One of the new approaches to the solution of this task is viewed in this article. For this purpose we use the new type of informative features named TAC-coefficients (Throat-Acoustic Correlation coefficients) which provide sufficient segmentation accuracy and effi- ciency.

Tribological Properties of Ti-Al Alloy Self-Lubricating Composite Materials

2013 ◽  
Vol 842 ◽  
pp. 114-117
Author(s):  
Xiu Ling Wang ◽  
Li Ying Yang ◽  
Shou Ren Wang ◽  
Yi Zhang
Keyword(s):  
Sliding Wear ◽  
Solid Lubricant ◽  
Al Alloy ◽  
Test Results ◽  
Weight Percentage ◽  
Dry Conditions ◽  
Hot Pressing Sintering ◽  
Worn Surface ◽  
Wear Tests ◽  
Self Lubricating Composites

A series of Ti-48Al-2Cr-2Nb/62%BaF2-38%CaF2 (CB) self-lubricating composites with addition of different weight percentage of solid lubricant were prepared by vacuum hot pressing sintering. Sliding wear tests against 45#steel were performed on the specimen in dry conditions, worn morphology was observed by the scanning electron microscope (SEM). The test results show that when addition of solid lubricant weight percentage is 10%, the worn surface of the composites is most smooth.The main wear mechanisms of Ti-48Al-2Cr-2Nb/62%BaF2-38%CaF2 composite are abrasive wear and adherent wear.

Wear Behaviour of TiC Coated AISI 4340 Steel Produced by TIG Surface Melting

2015 ◽  
Vol 819 ◽  
pp. 76-80 ◽  
Author(s):  
Md Abdul Maleque ◽  
Belal Ahmed Ghazal ◽  
Mohammad Yeakub Ali ◽  
Maan Hayyan ◽  
Abu Saleh Ahmed
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Steel Surface ◽  
Composite Layer ◽  
Wear Behaviour ◽  
Wear Volume ◽  
Coated Steel ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Aisi 4340

Coating possesses superior wear resistance which makes the material suitable for components subjected to dynamic applications under sever wearing condition and high temperature applications. In this study, TiC coating layer was synthesized by preplacing a 1 mg/mm2of fine size (~40 μm) TiC powder on the surface of AISI 4340 steel. The composite layer was produced by rapidly melting TiC powder together with the substrate steel using tungsten inert gas (TIG) torch welding at a fixed heat input of 1344 J/mm. The wear behaviour of the coated steel was investigated using a universal pin-on-disc tribometer. The microhardness profile of the coating showed increment of the hardness value (almost 5 times higher) than the substrate material. The wear test results showed that the TiC coated steel has lower wear volume loss hence, higher wear resistance compared to the substrate AISI 4340 steel. Incorporation of TiC into the steel surface has improved the wear behaviour of the steel by reduction of plastic deformation and ploughing of the steel surface. The SEM micrograph of the wear worn surface showed mild type of abrasive wear for coated steel whereas, the AISI 4340 steel showed severe type wear with excessive plastic deformation and ploughing.

Tribological properties of the epoxy resin-based solid lubricant coating modified by Kevlar fibers

2018 ◽  
Vol 70 (9) ◽  
pp. 1706-1713 ◽  
Author(s):  
Guotao Zhang ◽  
Yanguo Yin ◽  
Ting Xie ◽  
Dan Li ◽  
Ming Xu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Epoxy Resin ◽  
Tribological Properties ◽  
Dry Friction ◽  
Friction And Wear ◽  
Solid Lubricant ◽  
Transfer Film ◽  
Wear Properties ◽  
Content Type ◽  
Friction And Wear Properties

Purpose This paper aims to obtain high mechanical and good tribological properties of epoxy resin-based coatings under dry friction conditions. Design/methodology/approach Bonded solid lubricant coatings containing Kevlar fibres were prepared by a spraying method. The friction and wear properties of the coatings were experimentally investigated with a face-to-face tribometre under dry friction conditions. Scanning electron microscopy, energy dispersive X-ray spectroscopy and 3D laser scanning technologies were used to characterise the tribological properties. The action mechanism of the Kevlar fibres on a solid lubricant transfer film was also analysed. Findings Adding Kevlar fibres can significantly improve the wear resistance of the coatings. When the Kevlar fibre content increases, the tribological properties of the coatings improve and then worsen. Superior properties are obtained with 0.03 g of Kevlar fibres. Appropriately increasing the load or speed is beneficial to the removal of the outer epoxy resin and the formation of a lubricant film. During friction, the solid lubricants wrapped in the epoxy resin accumulate on the surface to form a transfer film that shows a good self-lubricating performance. In the later friction stage, fatigue cracks occur on the solid lubricant film but cannot connect to one another because of the high wear resistance and the entanglement of the rod-like Kevlar fibres. Thus, no large-area film falls from the matrix, thereby ensuring the long-term functioning of solid lubricant coatings. Originality/value Epoxy resin-based solid lubricant coatings modified by Kevlar fibres were prepared, and their friction and wear properties were investigated. Their tribological mechanisms were also proposed. This work provided a basis for the analysis of the tribological properties and design of bonded solid lubricant coatings containing Kevlar fibres.

scholarly journals Sliding Wear Performance of AlCrN Coating on TiB2/Ti Composites at High Temperatures

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6771
Author(s):  
Remigiusz Michalczewski ◽  
Marek Kalbarczyk ◽  
Zbigniew Słomka ◽  
Edyta Osuch-Słomka ◽  
Maciej Łuszcz ◽  
...  
Keyword(s):  
Wear Resistance ◽  
High Temperatures ◽  
Surface Oxidation ◽  
Manufacturing Technology ◽  
Tribological Behaviour ◽  
Composite Surface ◽  
Group Iii ◽  
High Adhesion ◽  
Group I ◽  
Coating Composite

The aim of the study was to investigate effect of Ti/TiB2 composite composition and manufacturing technology parameters on the tribological behaviour of AlCrN coating-composite system. The AlCrN coating was deposited by PVD (Physical Vapour Deposition) method. The composites were manufactured by spark plasma sintering (SPS) from three variants of powders mixtures: Ti with TiB2, Ti6Al4V with TiB2 as well as Ti with B, using (five) different sintering temperatures. For each of the developed coating-composite systems, the wear resistance was evaluated using ball-on-disc SRV tester, at six temperatures (from room temperature up to 900 °C). The results confirmed that high-temperature wear resistance of the coating–substrate combination depends on Ti/TiB2 composite composition and manufacturing technology parameters. In the case of uncoated composite, two processes manage the wear at high temperatures: cracking propagation and surface oxidation. The presence of AlCrN coating on the composite surface protects the surface against deep cracking and surface oxidation. The composites of Group I, sintered at 1250 °C from a mixture of pure Ti and TiB2 (50/50 wt.% ratio) as well as Group III, sintered at 1350 °C from a mixture of pure Ti and B allow the achievement of a satisfactory surface quality, a high adhesion of the PVD coating and moderate wear at high temperatures. However, the composite made of pure Ti and B seems to be a better solution for temperatures exceeding 600 °C.

scholarly journals Mechanical and Tribological Behaviour of Hybrid Multi Fibre Reinforced Nylon 6-6 Nanocomposites

2021 ◽  
Vol 58 (3) ◽  
pp. 137-147
Author(s):  
Pradeep Kumar Seethakaran ◽  
Gopalakrishnan Prabhakaran ◽  
Paulraj Jawahar
Keyword(s):  
Wear Resistance ◽  
Fatigue Life ◽  
Glass Fibre ◽  
Research Work ◽  
Nylon 6 ◽  
Wire Mesh ◽  
Thermoplastic Composites ◽  
Nano Silica ◽  
Tribological Behaviour ◽  
Load Impact

The investigation on the effect of adding silane modified chopped E-glass fibre and Aluminium metal wire-mesh into nano silica toughened nylon 6-6 thermoplastic composites on mechanical, drop load impact, fatigue and tribological behaviour is studied in this paper. The primary aim of this research work is to develop a hybrid Nylon 6-6 nanocomposites having high stiffness, toughness and wear resistance. The chopped glass fibre and Al wire-mesh was surface treated with the help of 3-Aminopropyletrimethoxylane (silane) and acid etching. The tensile results revealed that additions of glass fibre and Al mesh into nano - silica toughened nylon 6-6 composite gives improved tensile and flexural strength. Similarly, the Izod impact strength of Al-mesh reinforced nano silica (1vol.%) toughened nylon 6-6 gives superior energy absorption up to 6 Joules/cm. The drop load impact penetration of composite N3 (59% - Nylon 66, 20% - E-glass fibre, 20% - Al wire mesh and 1 % - nano silica) shows very limited penetration than other composites. Highest fatigue life of 16391 cycles was observed for the composite designated N3, which contains 1 vol.% of nano silica, whereas the composite containing 2 vol.% of nano silica gives very lower specific wear rate and Co-efficient of friction. The developed composite which has better modulus, stiffness, wear resistance and fatigue life could be possibly used in automobile power transmission gears, domestic equipment and farm related machineries.

Mechanical and Tribological Properties of W(100-x)%Cx% Coatings Deposited by DC Magnetron Sputtering

2015 ◽  
Vol 642 ◽  
pp. 184-189
Author(s):  
Yan Liang Su ◽  
Yueh Feng Lin
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Mechanical And Tribological Properties ◽  
Unbalanced Magnetron Sputtering ◽  
Unbalanced Magnetron ◽  
Pin On Disc ◽  
Dry Conditions ◽  
Coating Microstructure

W(100-x)%Cx% coatings with different tungsten and carbon contents were deposited by unbalanced magnetron sputtering. The microstructures and mechanical properties of the W(100-x)%C x% coatings was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), nanoindentation and adhesion testing techniques. The tribological performance of the coatings was investigated using a pin-on-disc trobometer under dry conditions. Experimental results indicated that coating microstructure, mechanical properties and wear resistance varied according to the tungsten and carbon contents of the coatings. The W72%C28% coating had the highest hardness/elastic modulus (H/E) ratio. In the ball-on-disc wear tests, it was found that the W72%C28% coating exhibited the best wear resistance.

Lubricated Wear of Machinable Lithium Disilicate Glass Ceramic

2017 ◽  
Vol 739 ◽  
pp. 18-22
Author(s):  
Laura Elbourne-Binns ◽  
Juan Carlos Baena ◽  
Ling Yin ◽  
Zhong Xiao Peng
Keyword(s):  
Surface Roughness ◽  
Glass Ceramic ◽  
Sliding Friction ◽  
Surface Preparation ◽  
Lithium Disilicate ◽  
Wear Volume ◽  
Oral Environment ◽  
Dry Conditions ◽  
Applied Forces ◽  
Lubrication Conditions

An experimental investigation was performed to study the wear of a promising dental ceramic, i.e., machinable lithium disilicate glass ceramic, under lubrication conditions, in particular, to examine effects of the surface finish and applied load on wear. Our previous work has shown that a fine finish in a dry condition did not necessarily translate to the lowest wear volume due to changes in the dominant wear mechanisms. This study tested the ceramic specimens with four average surface roughness values of Sa = 143 nm, 217 nm, 353 nm, and 692 nm on a reciprocating sliding friction rig against alumina balls with two applied forces of 5 N and 25 N in a bath of distilled water. Comparing with the results obtained in the dry conditions, this study shows that surface roughness of approximately 200 nm may be suitable for surface preparation of crowns made from the material in the wet and dry wear conditions in the oral environment.

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