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Journal Cover
Tribology in Industry
Journal Prestige (SJR): 0.429
Citation Impact (citeScore): 1
Number of Followers: 2  

  This is an Open Access Journal Open Access journal
ISSN (Print) 0354-8996 - ISSN (Online) 2217-7965
Published by U of Kragujevac Homepage  [2 journals]
  • Numerical Modeling of Rough Contact between Two Cylinders with Axes

    • Abstract:
      Authors M.B.A. Aidoudi, J. Bessrour
      The present paper represents a study of the effect of surface roughness in elastic-plastic micro contact between two cylinders in contact along their external generatrix by finite element analysis. This is the first study in the micro-scale geometry to analyze this particular contact used in industrial problem of fluid heat tracing. Two types of frictionless contact are investigated numerically. One examines the contact between two random rough cylindrical surfaces with Gaussian statistics for different topographies. The other proposed the contact between sum cylindrical surface which include the roughness and the elasticity of the both rough surfaces into contact, with perfectly smooth rigid cylindrical surface. The construction of sum surface is used in order to simplify the problem of rough contact. A full description of the method and the technical of construction of sum surface is presented. As a result, it was fund a good agreement between the two models. A multiple contact configuration was analysed in the form of cylindrical surface. Numerical results obtained under elastic conditions were also validated by comparison with theoretical solution of Hertz. A sensitivity analysis is presented in order to estimate the random draw of parameters on the results. We present then results showing the effects of roughness on contact parameters. Overall, it is found that the contact parameters are quite sensitive to the roughness parameters in elastic and plastic deformation. Results show that the surface topography has a large influence on the real area of contact. As a result of that, the real contact area ratio increases with the increasing of the displacement until it reaches a maximum limit value on elastic-plastic deformation. This value, less than unity, decreases with increasing roughness.
      Keywords Contact mechanics, Rough cylindrical surface, Microgeometry, Sum surface, Elastic-plastic, Gaussian surface, Finite Element Analysis

      DOI :10.24874/ti.2017.39.04.01
      PubDate: 15 December 2017 12:00:00 +01
  • Effect of Changing Ellipiticity Ratio on the Formation of Ultra-Thin
           Lubricating Film

    • Abstract:
      Authors M.F. Abd Al-Samieh
      The mechanism of fluid film lubrication in ultra-thin conjunction under elliptical point contacts is discussed in this paper. The results of changing the ellipticity ratio are highlighted. The operating conditions; load and speed of entraining motion, promote formation of ultra-thin films that are formed under the combined action of Elastohydrodynamic lubrication (EHL), surface contact force of solvation and molecular interactions due to presence of Van der Waals' force. The paper shows that, changing the ellipticity ratio maintain the general behavior of the formation of ultra-thin lubricating film thickness as in the case of circular point contact problem when the contiguous solids are subject to light-to-medium contact loads and the effects of surface forces become significant as the elastic film (i.e. the gap) is reduced to a few nanometers and lubricant discretisation appears.
      Keywords Ultra-thin films, Elastohydrodynamics, Solvation, Van der Waals' force, Ellipiticity ratio

      DOI :10.24874/ti.2017.39.04.02
      PubDate: 15 December 2017 12:00:00 +01
  • Enhancement in the Tribological and Mechanical Properties of Electroless
           Nickel-Nanodiamond Coatings Plated on Iron

    • Abstract:
      Authors Z. Karaguiozova, J. Kaleicheva, V. Mishev, G. Nikolcheva
      A technology to improve the tribological and mechanical surface properties of iron alloys is developed based on the electroless nickel plating. The technology combines sol-gel and electroless deposition technique. Novel nanocomposite coatings are obtained consisting of Nickel-phosphorus-nanodiamond (Ni-P-ND). The ND sol is added directly to the electroless Ni-P solution. A suitable surfactant is added to achieve well-dispersed ND particles in the electroless solution to facilitate their embodiment and equal distribution in the coating. Substrates of steel 17CrNiMo6 and spheroidal graphite cast irons are used for the manufacture of the iron alloys specimens. The surface morphology and microstructure observation performed by scanning electron microscopy (SEM) and optical metallography confirms the influence of ND particles on the coating structure. The structural phase investigation by X Ray analysis indicates a transformation of the amorphous phase to a crystalline one such as Ni, Ni3P after coatings' heat treatment. The microhardness investigation by Knoop Method and wear resistance measurement in accordance with the Polish Standard PN-83/H-04302 of Ni-P and Ni-P-ND composite coatings are evaluated and compared with each other. The increase in the value of hardness and wear resistance of Ni-P composite coatings in the presence of ND particles and after heat treatment is obtained.
      KeywordsDetonation nanodiamond, Electroless nickel coating, Wear resistance, Microhardness, Microstructure

      DOI :10.24874/ti.2017.39.04.03
      PubDate: 15 December 2017 12:00:00 +01
  • Theoretical and Experimental Investigations of the Rotor Vibration
           Amplitude of the Turbocharger and Bearings Temperature

    • Abstract:
      Authors E. Zadorozhnaya, S. Sibiryakov, V. Hudyakov
      One of the most urgent issues of the modern world and domestic automobile and tractor production is the problem of the production of efficient and reliable turbochargers. The rotor bearings largely determine the reliable operation of the turbocharger. By increasing the degree of the forcing of the engine the turbocharger rotor speed and the load increases significantly. Working conditions of bearings also complicated because of the temperature rise. In this case the bearing of the turbine and the compressor bearing works in different thermal conditions. The definition of the thermal state of the bearings can be performed experimentally. However, to perform these studies the sophisticated experimental equipment must be used. Researchers can't perform experiments for each type of turbocharger. Therefore, the applying of the theoretical approaches becomes more relevant. The peculiarity of the considered problem is the design of the bearings, which are made in the form of multilayer bearings with floating rings. Such designs increase the number of the parameters that affect the behaviour of the rotor. For the calculation of the multilayer bearings and turbocharger rotor dynamics a method and calculation algorithm was developed. A plan of the experiment based on the orthogonal central composite plan was drawn up. The regression equations for rotor amplitude and bearing temperature were obtained. As variable parameters the clearances (external and internal), rotor speed, pressure and lubricant temperature were used. The results of the calculation were compared with experimental results obtained at the plant. Non-Newtonian properties of the lubricants were taken into account in the calculations. Comparative results showed good agreement. In this way the resulting function can be applied to studies of the similarly multilayer bearings without complicated experimental studies.
      Keywords Rotor of the turbocharger, Multilayer bearings, Thermal state, Precession amplitude, Calculation method

      DOI :10.24874/ti.2017.39.04.04
      PubDate: 15 December 2017 12:00:00 +01
  • Contact Pressure and Sliding Velocity Maps of the Friction, Wear and
           Emission from a Low-Metallic/Cast-Iron Disc Brake Contact Pair

    • Abstract:
      Authors J. Wahlström, V. Matejka, Y. Lyu, A. Söderberg
      Particulate matter with an aerodynamic diameter less than 10 µm (PM10) from car disc brakes contribute up to 50% of the total non-exhaust emissions from road transport in the EU. These emissions come from the wear of the pad and rotor contact surfaces. Yet few studies have reported contact pressures and offered sliding speed maps of the friction, wear, and particle emission performance of disc brake materials at a material level. Such maps are crucial to understanding material behaviour at different loads and can be used as input data to numerical simulations. A low-metallic pad and grey cast-iron rotor contact pair commonly used today in passenger car disc brakes was studied using a pin-on-disc tribometer at twelve contact pressure and sliding speed combinations. Maps of the coefficient of friction, specific wear rate, particle number, and mass rate are presented and discussed.
      Keywords Disc brake, Pin-on-disc, Emissions, Friction, Wear, Maps

      DOI :10.24874/ti.2017.39.04.05
      PubDate: 15 December 2017 12:00:00 +01
  • Study of the Parametric Performance of Solid Particle Erosion Wear under
           the Slurry Pot Test Rig

    • Abstract:
      Authors S.R. More, D.V. Bhatt, J.V. Menghani
      Stainless Steel (SS) 304 is commonly used material for slurry handling applications like pipelines, valves, pumps and other equipment's. Slurry erosion wear is a common problem in many engineering applications like process industry, thermal and hydraulic power plants and slurry handling equipments. In this paper, experimental investigation of the influence of solid particle size, impact velocity, impact angle and solid concentration parameters in slurry erosion wear behavior of SS 304 using slurry pot test rig. In this study the design of experiments was considered using Taguchi technique. A comparison has been made for the experimental and Taguchi technique results. The erosion wear morphology was studied using micro-graph obtained by scanning electron microscope (SEM) analysis. At shallow impact angle 30°, the material removal pattern was observed in the form of micro displacing, scratching and ploughing with plastic deformation of the material. At 60° impact angle, mixed type of micro indentations and pitting action is observed. At normal impact angle 90°, the material removal pattern was observed in form of indentation and rounded lips. It is found that particle velocity was the most influence factor than impact angle, size and solid concentration. From this investigation, it can be concluded that the slurry erosion wear is minimized by controlling the slurry flow velocity which improves the service life of the slurry handling equipments. From the comparison of experimental and Taguchi experimental design results it is found that the percentage deviation was very small with a higher correlation coefficient (r2) 0.987 which is agreeable.
      Keywords Taguchi method, Slurry pot Test Rig, Erosion wear, SS304

      DOI :10.24874/ti.2017.39.04.06
      PubDate: 15 December 2017 12:00:00 +01
  • Effect of Different Fillers on Adhesive Wear Properties of Glass Fiber
           Reinforced Polyester Composites

    • Abstract:
      Authors E. Feyzullahoğlu
      Polymeric composites are used for different aims as substitute of traditional materials such as metals; due to their improved strength at small specific weight. The fiber reinforced polymer (FRP) composite material consists of polymeric matrix and reinforcing material. Polymeric materials are commonly reinforced with synthetic fibers such as glass and carbon. The glass fiber reinforced polyester (GFRP) composites are used with different filler materials. The aim of this study is to investigate the effects of different filler materials on adhesive wear behavior of GFRP. In this experimental study; polymetilmetacrilat (PMMA), Glass beads (GB) and Glass sand (GS) were used as filling material in GFRP composite samples. The adhesive wear behaviors of samples were carried out using ball on disc type tribometer. The friction force and coefficient of friction were measured during the test. The volume loss and wear rate values of samples were calculated according to test results. Barcol hardness values of samples were measured. The densities of samples were measured. Results show that the wear resistance of GB filled GFRP composite samples was much more than non-filled and PMMA filled GFRP composite samples.
      Keywords Glass Fiber, Polyester, Filler Materials, Adhesive Wear

      DOI :10.24874/ti.2017.39.04.07
      PubDate: 15 December 2017 12:00:00 +01
  • Wear Analysis of Top Piston Ring to Reduce Top Ring Reversal Bore Wear

    • Abstract:
      Authors P. Ilanthirayan, S. Mohanraj, M. Kalayarasan
      The piston rings are the most important part in engine which controls the lubricating oil consumption and blowby of the gases. The lubricating film of oil is provided to seal of gases towards crankcase and also to give smooth friction free translatory motion between rings and liner. Of the three rings present top ring is more crucial as it does the main work of restricting gases downwards the crankcase. Boundary lubrication is present at the Top dead centre (TDC) and Bottom dead centre (BDC) of the liner surface. In addition to this, top ring is exposed to high temperature gases which makes the oil present near the top ring to get evaporated and decreasing its viscosity, making metal-metal contact most of the time. Due to this at TDC, excess wear happens on the liner which is termed as Top ring reversal bore wear. The wear rate depends upon many parameters such as lubrication condition, viscosity index, contact type, normal forces acting on ring, geometry of ring face, surface roughness, material property. The present work explores the wear depth for different geometries of barrel ring using Finite Element model with the help of Archard wear law and the same is validated through experimentation. The study reveals that Asymmetric barrel rings have less contact pressure which in turn reduces the wear at Top dead centre.
      Keywords Top ring, Wear depth, Boundary lubrication, Skewed barrel ring, Archard Law

      DOI :10.24874/ti.2017.39.04.08
      PubDate: 15 December 2017 12:00:00 +01
  • Development of Entada Mannii Fiber Polypropylene Matrix Composites for
           Light Weight Applications

    • Abstract:
      Authors O.P. Balogun, J.A. Omotoyinbo, K.K. Alaneme, P.A. Olubambi
      This study investigates the use of Entada mannii fiber as potential reinforcement of thermoplastic composites suitable for light weight applications. Composites of 5 wt.%, 10 wt.% and 15 wt.% were produced by compression moulding with 5 wt.% Maleic anhydride polypropylene (MAAP) as compatibilizers. Tensile properties, impact strength and hardness properties of the composites were evaluated. Thermogravimetric analysis (TGA), X-ray diffractograms (XRD) and Fourier transformed infrared spectroscopy (FTIR) of treated and untreated fibers were evaluated while the fractographic analysis of surface morphology of the composites was performed using Scanning electron microscopy. The result revealed that reinforcing thermoplastic with 15 %.wt treated Entada mannii fiber revealed a greater improvement in tensile strength and Young's modulus by 58 % and 61 % respectively relative to pure PP and the hardness properties of the composite also increased by 56 % as compared with pure PP . This improvement is noticeable for the 15 wt.% treated fiber reinforced composites and could be attributed to good interfacial bonding between the fiber and the matrix. However impact strength of treated fiber composite revealed an improvement with 10 wt.% treated fiber composites by 48 % relative to Pure PP. Fracture surface images of treated fiber reinforced composites revealed less fiber pullout while the TGA showed the treated fiber degrades at higher temperature as compared with untreated fiber. Thus, the cellulose percentage crystallinity index of the treated fiber increases from 47.9 % to 57 % as a result of the influence of alkaline treatment.
      Keywords Mechanical properties, Fiber composites, Entada mannii fiber, Fracture surface, Compatibilizers, Interfacial bonding

      DOI :10.24874/ti.2017.39.04.09
      PubDate: 15 December 2017 12:00:00 +01
  • Frictional Response of Lubricant in EHL Contact under Transient
           Bi-directional Shear Loading

    • Abstract:
      Authors J. Fryza, P. Sperka, I. Krupka, M. Hartl
      Consideration of performance, efficiency and energy consumption is nowadays an inherent part of the design of every modern machine. These factors are mainly determined by mechanisms taking place within the lubricated contacts. Unfortunately, the physical origins of these mechanisms have been investigated exclusively for steady conditions that do not occur in actual contacts of machines affected by vibrations. This study presents novel experimental data describing friction in the elastohydrodynamically lubricated contact exposed to the main steady sliding motion along with lateral sliding micro-oscillations. Friction forces were measured simultaneously in two perpendicular directions of point contact. It is shown that the lubricant response in the main direction of motion suffers from shear thinning and thermal effects whereas its lateral response is isothermal Newtonian. Moreover, the lateral friction affects the friction in the main direction, but not vice versa, when the majority of shear flow is maintained in this main direction. These finding are attributed to the perturbation of structural arrangement of lubricant. The results also suggest that a response of mineral oils to shearing is anisotropic. A limiting shear stress is discussed since the total friction was not able to exceed a certain value.
      Keywords Elastohydrodynamic lubrication, Friction, Shear flow, Non-steady state, Limiting shear stress

      DOI :10.24874/ti.2017.39.04.10
      PubDate: 15 December 2017 12:00:00 +01
  • Investigation of Friction Coefficient of Various Polymers Used in Rapid
           Prototyping Technologies with Different Settings of 3D Printing

    • Abstract: Author S. Perepelkina, P. Kovalenko, R. Pechenko, K. Makhmudova
      This paper deals with the research of friction coefficient in tribopairs made of the polymers that are the most commonly used in rapid prototyping technologies. Parts manufactured with the use of a 3D printer with different settings of printing were chosen as samples for the experimental research. Friction coefficient and the temperature in the contact area during the runtime were measured using a universal friction machine MTU-1. The machine allows us to carry out tribological experiments using different contact schemes with or without lubricants. For this research, the scheme "plate-on-plate" was chosen. No lubricants were used. Wear of the samples was estimated after the experiments. Analysis of the experimental data has shown that changing of 3D printing settings has significant influence not only on the strength and stiffness of the parts, but also on the quality of the surface that affects the tribological properties of the tribopairs. The results of this research allow us to choose optimal settings for 3D printing depending on the required tribological properties of the parts, such as friction coefficient and wear.
      Keywords Friction coefficient, Tribological properties, Wear, Temperature in the contact area, Rapid prototyping technologies, 3D printing settings, Universal friction machine

      DOI :10.24874/ti.2017.39.04.11
      PubDate: 15 December 2017 12:00:00 +01
  • Characteristic Evaluation of Brake Block Material

    • Abstract: Author E. Surojo, Jamasri, V. Malau, M.N. Ilman
      This paper reports on a comparison of the frictional characteristics of three different samples of brake block materials. Two commercial brake blocks (composite and grey iron/metallic) and a non-commercial composite brake block were extracted to form pins (specimens), and then their frictional properties were evaluated using a pin-on-disc apparatus. The non-commercial composite brake block that was investigated in this work was developed as a substitute for the grey iron brake block. The results revealed that the composite brake blocks had a higher wear resistance and were more stable in terms of their coefficient of friction at various contact pressures and sliding speeds compared to the grey iron brake block. The non-commercial composite brake block that was developed in this research had a coefficient of friction that was close to that of the grey iron brake block, and hence, it can be considered as a substitute for the grey iron brake block.
      Keywords Composite brake block, Grey iron brake block, Frictional characteristics

      DOI :10.24874/ti.2017.39.04.12
      PubDate: 15 December 2017 12:00:00 +01
  • Stability Loss of the Cemented Stem of Hip Prosthesis due to Fretting
           Corrosion Fatigue

    • Abstract:
      Authors L. Capitanu, L.-L. Badita, V. Florescu
      Aim of this project was to study the fretting behaviour of the cemented femoral stem fixation of a total hip prosthesis, trying to capture the loss of contact between the femoral stem and polymetylmethacrilate cement fixation. To have a landmark, studies were performed compared with cementless fixation, where no fretting phenomenon occurs, on real prostheses, under biological 3D loading conditions. A fatigue test device, installed on a servo-hydraulic triaxial dynamic testing machine was used. It allowed monitoring the flexion-extension, abduction-adduction, inner-outer rotation movements, and the variation of the torsional torque, depending on normal loading. The test ends when the sample does not fail after 2000000 cycles, or when it has reached a predetermined number of cycles. Test fluid medium used was NaCl mixed with distilled water, a favourable environment for appearance of fretting corrosion. After the failure of stem fixation at 2450000 cycles, the mantle of bone cement remaining adherent on femoral stem was removed. Microscopic inspection of the femoral stem and of the inner part of the polymetylmethacrilate mantle demonstrated the existence of corrosion of the femoral stem surface beneath the cement mantle, and Fe2O3 deposits on the femoral stem surface and on the inner part of the mantle.
      Keywords Hip prosthesis, Ti6Al4V, Polymetylmethacrilate, Cemented stem, Fretting fatigue corrosion

      DOI :10.24874/ti.2017.39.04.13
      PubDate: 15 December 2017 12:00:00 +01
  • Filtration Systems Design for Universal Oils in Agricultural Tractors

    • Abstract:
      Authors R. Majdan, Z. Tkáč, R. Abrahám, K. Kollárová, I. Vitázek, M. Halenár
      Three filtration systems using the tractor hydraulic circuit were proposed and verified during the tractors operation. Using the tractor-implement hydraulic system and filter body with accessories the universally useful filtration systems were designed. The designed filtration systems are the second stage of universal oil filtration whereas the first stage is the standard tractor filter. The decrease in the content of iron reached the values 25.53 %, 32.95 % and 41.55 % and the average decrease in oil contamination characterized by average value of decrease in content of iron, copper and silicium reached values 24.3 %, 24.7 % and 35.53 % in dependence on the filtration system and an oil contamination level. The decrease in contamination level verified the ability of designed filtration systems for agricultural tractors.
      Keywords Lubricating oil properties, Cleanliness level, Spectroscopy, Hydraulic circuit

      DOI :10.24874/ti.2017.39.04.14
      PubDate: 15 December 2017 12:00:00 +01
  • Characterization of Tribological Properties of Greases for Industrial
           Circuit Breakers

    • Abstract:
      Authors B. Castaños, C. Bazurto, L. Peña-Parás, D. Maldonado-Cortés, J. Rodríguez-Salinas
      Proper grease selection is essential for the electrical industry to minimize friction and wear between the components of circuit breakers under mechanical contact. In this investigation, the tribological properties of commercially available greases for industrial circuit breakers were evaluated. Three tribological tests were performed: the ITeE-PIB Polish Method for testing lubricants under scuffing conditions (extreme pressure, EP), a four-ball test under ASTM D 2266 (anti-wear, AW), and a ball-on-disk test based on ASTM G-99. The worn materials were characterized with an optical 3D profilometer measurement system and a scanning electron microscope (SEM). Additionally, selected greases with the best tribological performance were tested on a testing bench intended for circuit breakers, according to electrical safety standards, which validated the results obtained in the laboratory.
      Keywords Lubricating greases, Wear, Load carrying capacity, Circuit breaker

      DOI :10.24874/ti.2017.39.04.15
      PubDate: 15 December 2017 12:00:00 +01
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Heriot-Watt University
Edinburgh, EH14 4AS, UK
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