Publisher: U of Kragujevac   (Total: 2 journals)   [Sort by number of followers]

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Applied Engineering Letters     Open Access   (Followers: 1)
Tribology in Industry     Open Access   (Followers: 2, SJR: 0.429, CiteScore: 1)
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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]
  • Study on Frictional Properties of Fine Powder Materials

    • Abstract:
      Authors Alexander Gritsenko, Alexander Baryshnikov, Vladimir Shepelev, Beibit Kaliyev
      The operating parameters of present-day engines depend on many factors, including the lubrication system. The lubrication system not only reduces friction between the surfaces of moving parts, but also contributes to their cooling and cleans engine parts from carbon deposits and impurities. High environmental requirements are also imposed on the quality of the lubricants, while maintaining their specifications. To that end, various additives are added to lubricating oil. The paper studies the effect of fine powders (enamels) on the wear of friction pairs in laboratory tests. The tests are mainly carried out for all-season synthetic and mineral oils in demand. Such criteria as wear of a roller and upper and lower bearings, specific wear of friction pairs, moment load, and temperature are selected as the effectiveness evaluation criteria of the use of enamels and nanomaterials. Experimental studies show a high efficiency of using enamels as additives to reduce friction and increase the load-carrying capacity of oils. The temperature in the friction layer is reduced by 10-20%, depending on the enamel concentration in the oil. The enamel acts as a third body with a lower friction coefficient and energy to failure, which increases the actual contact area of the friction pairs. The results of the study can be applied in the development of motor oils with fine enamel as an additive.
      KeywordsTriboengineering, Friction, Wear, Oil, Additive

      DOI :10.24874/ti.1208.11.21.02
      PubDate: 15 March 2022 12:00:00 +0100
  • Simulation of Misaligned Journal Bearings Using Neural Networks

    • Abstract:
      Authors Kyriakos A. Kokkinidis, Pantelis G. Nikolakopoulos
      Utilization of smart systems, i.e. software tools that incorporate artificial intelligence (AI), in engineering applications increases. This fact is due to their ability to study the performance of complicated systems, producing results quicker and easier than typical analytical models. This article is focused on the advantages of using Artificial Neural Networks (ANNs) to solve the problem of a misaligned hydrodynamic journal bearing. Firstly, the Reynolds equation is solved using finite difference method (FDM) for different operating and misalignment conditions. The results are used to train four (4) artificial neural networks, one for each design parameter. Afterwards, the networks are tested for several operational characteristics and compared with the results of the finite difference method. The outcome is that the force and the torque can be predicted with maximum error of approximately 5% with less computational cost than the finite difference method.
      KeywordsJournal bearings, Neural networks FDM, Misalignment

      DOI :10.24874/ti.1078.03.21.10
      PubDate: 15 March 2022 12:00:00 +0100
  • Machining Aspects of Al2O3 Nano Cutting Fluids – A Comparative Study

    • Abstract:
      Authors Mukkamala Usha, Gunji Srinivasa Rao
      Health and environmental concerns on usage and disposal of cutting fluids during machining has led to development of minimum quantity lubrication (MQL) technique which requires specialized fluids having superior properties. Nano particle-based lubricating fluids have been found to satisfy the properties for cutting fluids used in MQL. Nano particles are synthesized using various techniques. Herbal based synthesis is a recent advancement in preparation of nano particles. In the present work, fluids prepared from herbal based synthesis was compared with non-herbal synthesis, and were evaluated for their lubricating properties like thermal conductivity and viscosity. Both fluids were used in turning process via MQL and measurements were taken of the cutting forces and surface roughness. Regression equations were developed and 3D surface graphs were drawn for the measured responses among herbal nanofluid, non-herbal nanofluid and dry machining. Based on the analysis, herbal based nanofluid showed improvement in the responses compared to non-herbal synthesized nano fluid and also when compared to dry machining.
      KeywordsCentral composite face centered, Design of experiments, Herbal nano particles, MQL, Nano cutting fluids, Response surface methodology, Regression equations

      DOI :10.24874/ti.1032.12.20.03
      PubDate: 15 March 2022 12:00:00 +0100
  • Investigation of the Effect of Temperature on the Contact Characteristics
           and Resource of Metal-Polymer Plain Bearings

    • Abstract:
      Authors Myron Chernets, Anatolii Kornienko, Svetlana Fedorchuk, Yuriy Chernets
      Using the developed methodology for calculating hybrid (metal-polymer) plain bearings, a study of the effect of temperature on the contact parameters and their resource was conducted. Metal-polymer bearings with a bushing made of polyamide PA6 reinforced with glass or carbon dispersed fibers were considered. The calculation of the maximum initial contact pressures and their change due to wear of the bushing was performed. The predictive estimate of resource of the investigated bearings at various loadings was carried out. Quantitative and qualitative patterns of changes in the maximum initial contact pressures and bearing resource with increasing temperature were established. Studies show that the decrease in the modulus of elasticity due to increasing temperature leads to a decrease in the maximum pressure and increase the resource of metal-polymer bearings, which is useful. This phenomenon is due to a decrease in the rigidity of the polymer composite.
      KeywordsMetal-polymer plain bearings, Filled polyamide, Dispersed glass and carbon fibers, Effect of temperature on the Young's modulus, Maximum contact pressures, Resource

      DOI :10.24874/ti.1100.04.21.07
      PubDate: 15 March 2022 12:00:00 +0100
  • Estimation of Wear Performance of Al-based Composite Reinforced with Al2O3
           and MoS2 Using Taguchi Approach

    • Abstract:
      Authors Hari Kiran Vuddagiri, Hota Ravisankar
      The present study is focused on the tribological performance of Molybdenum disulfide (MoS2), and Alumina (Al2O3) used as reinforcement in Al-Si-Mg alloy. By adapting the stir casting route, aluminum matrix composites (AMCs) are manufactured. The process variables such as weight percent of reinforcement i.e., Al2O3 (4, 8, 12 and 16 wt. percent ), and MoS2 (2 and 4 wt. percent), sliding velocity (1 m/s, 1.5 m/s, and 2 m/s), and load (10, 20 and 30 N), on tribological responses are wear rate and coefficient of friction. The experiments are intended to use the Taguchi Orthogonal array (L27). Mechanical properties such as hardness and tensile strength have been evaluated and hybrid metal matrix composites (HMC) have shown significant improvement. Analysis of Variance (ANOVA) revealed wear rate and coefficient of friction decreased with an increase in sliding speed and increased with the applied load. The worn-out, fractured composite surfaces are examined by a scanning electron microscope (SEM). A predominant wear mechanism is observed at low load has a combination of adhesive and abrasive wear, accompanied by high load as adhesive wear. The hybrid composites exhibited improved wear resistance and low friction coefficient as compared to the base alloy.
      KeywordsAMCs, Wear rate, Coefficient of friction, Alumina (Al2O3), Molybdenum disulfide (MoS2)

      DOI :10.24874/ti.1025.12.20.04
      PubDate: 15 March 2022 12:00:00 +0100
  • Influence of Thermal Degradation on the Mechanical Properties of Coatings
           [8YSZ/Al2O3]n Subjected to Thermals Cycles

    • Abstract:
      Authors Christian Ortiz Ortiz, Erick Hernandez-Rengifo, Julio Cesar Caicedo
      This study is based on the thermal degradation presented in the multilayer coatings [8YSZ/a- Al2O3]n when subjected to thermal cycles, focusing mainly on the analysis of the mechanical properties before and after these. To determine thermal degradation, the coatings were analyzed by XRD before and after thermal cycling. From these results, the presence of a tetragonal phase and an alpha phase belonging to (8YSZ and Al2O3) respectively was determined before the thermal cycles. After the cycles, show new peaks attributed to 2 important factors, the appearance of a monoclinic and cubic phase belonging to 8YSZ and peaks due to the presence of substrate oxides produced by a delamination of the coating and that decreased in intensity as increase in the bilayers number. Mainly, it was determined for the 70 bilayers coating, which presented the best mechanical properties before the thermal cycles, a decrease of 34.44% and 6.41% for hardness and elasticity modulus respectively, after the thermal cycles. From this research, it was concluded that the coating [8YSZ/a- Al2O3]n with 70 bilayers, presented the highest resistance to thermal wear generated in the coatings.
      KeywordsThermal Barrier Coatings, Mechanical Properties, Cyclic Oxidation, Multilayer Coating, Degradation Thermal

      DOI :10.24874/ti.1062.02.21.06
      PubDate: 15 March 2022 12:00:00 +0100
  • Experimental Investigation of Textured Inserts on Machining Performance of
           Al-MMC Using Taguchi Method

    • Abstract:
      Authors Devaraj Sandiri, Ramakrishna Malkapuram, Singaravel Balasubramaniyan
      Textured inserts coupled with solid lubricant is a good alternative to hydro carbon oil based cutting fluid. In this work, turning process is performed on Aluminium based Metal Matrix Composites (Al-MMC) using different types of textured cutting insert with solid lubrication. Three different types of textured inserts namely micro hole, perpendicular direction and parallel direction textured cutting inserts and Tungsten disulfide (WS2) is used as solid lubricant. Statistical tool such as Taguchi method is used to analyze the experimental results. The following results are noticed that, micro hole textured inserts are given better machining performance than parallel type and perpendicular type pattern textured inserts. The major role of textured inserts with solid lubrication is observed that fracture of WS2, low and stable coefficient of friction during machining. The optimum values are 120 m/min of cutting speed, 0.1 mm/rev of feed rate with micro hole type texture. The result of ANOVA method reveals that the types of texture is the most influencing parameter having value of 40.5% followed by cutting speed and feed rate with 29% and 20% respectively.
      KeywordsTurning process, MMC, Textured inserts, Taguchi, ANOVA

      DOI :10.24874/ti.1019.12.20.04
      PubDate: 15 March 2022 12:00:00 +0100
  • Effect of Frictional Material on Thermal Behavior of Brake System

    • Abstract:
      Authors Aliyaa Q. Mohammed, Ihsan Y. Hussain, Oday I. Abdullah
      The brake system is one of the most important systems in all vehicles. The main objective of this system is to control the vehicle mechanical movement and stopping. Where, it can’t drive safely any vehicle without the brake system to control its acceleration rate and its stability. The effective factors that affected the brake performance are the properties of frictional material of pads and disc. The objective of the present work is to study the thermal behavior of the brake system using different types of frictional material for pads and find the optimal one of them. High amount of heat will be generated between the disc and pads during the braking process; may cause quick failure in future. In the present paper, a 3-dimensional thermal transient model of the brake system has been developed using finite element technique (COMSOL Multiphysics® 5.5). Five types of friction materials (St37-2, HCC, G95, LUK, and Tiger) are used in the numerical analyses. The results presented the variation and distribution of contact temperatures of the proposed frictional materials during braking period. The main conclusion based on the obtained results is that the optimal frictional material is HCC material and the poorest one is LUK material.
      KeywordsPBrake system, Frictional Materials, Thermal behavior, Finite Element Analysis

      DOI :10.24874/ti.1071.03.21.07
      PubDate: 15 March 2022 12:00:00 +0100
  • Gravimetric, Electrochemical and Theoretical Study on Corrosion of
           AA6061/3wt% SiC/3wt% B4C Hybrid Composite in Acid Medium Using EDTA

    • Abstract:
      Authors Juan David Escobar Robledo, Prakasha Shetty, P. Preethi Kumari, M.C. Gowri Shankar, Sneha Kagatikar
      The corrosion behaviour of Al6061/3wt%SiC/3wt%B4C hybrid composite was investigated in the presence of 0.5M HCl medium using gravimetric, electrochemical, and theoretical methods. In the present work, ethylenediaminetetraacetic acid disodium (EDTA) was used as an eco-friendly inhibitor. EDTA showed mixed inhibitor behavior, and its inhibition performance decreased with rising temperature from 303 to 323 K. EDTA evinced maximum inhibition efficiency of 82 % at 1.074 mM. The kinetic and thermodynamic results controlling corrosion were evaluated. The inhibition process occurred through the adsorption of EDTA on the hybrid composite sample, which obeyed Langmuir's adsorption isotherm. The experimental results were validated by theoretical study. The corroded and inhibited specimen's surface analysis performed using scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed the adsorption of EDTA on the hybrid composite surface.
      KeywordsAA6061 hybrid composite, Corrosion inhibition, Potentiodynamic, Surface study, EDTA

      DOI :10.24874/ti.1052.02.21.05
      PubDate: 15 March 2022 12:00:00 +0100
  • Evaluation of the Hardness and Wear Resistance of Alloyed Coatings From
           Fastening CuSn/CrxCy Mixture Hardened by Plasma and Laser

    • Abstract:
      Authors Van Trieu Nguyen, Natalya Anatolyevna Astafeva, Aleksandr Gennadievich Tikhonov, Andrey Evgenievich Balanovskiy, Van Huy Vu
      This article provides an assessment of the possibility of increasing the wear resistance of the alloyed surface layer for steel St3 during plasma and laser heating of the applied surface pre-coating of the mixture of CuSn/CrxCy alloys. Plasma is more suitable for reflow a pre-deposited layer of CuSn/CrxCy with a wide range of particle sizes than laser treatment. As a result, plasma coatings have a high hardness (460-700 HV) compared to laser coatings (250-500 HV). The tests carried out showed that the wear resistance increases in the following order: Steel St3
      PubDate: 15 March 2022 12:00:00 +0100
  • Effect of Varying Stand-off Distance on Tribological and Mechanical
           Properties of Plasma Sprayed Hydroxyapatite Coated Metallic Substrates

    • Abstract:
      Authors Sachin Solanke, Vivek Gaval, Ravi Thakur, Amit Pratap
      Plasma spray technique is commonly used for the fabrication of hydroxyapatite (HA) coating for bio implants. Out of various process parameters in plasma spray technique, stand-off distance is one of the most important parameter which affects tribological and mechanical properties of the substrate. In the present work, HA powder was plasma sprayed onto Titanium grade 2 and Titanium grade 5 metallic substrates by varying standoff distance. Wear test was carried out to determine coefficient of friction and wear weight loss in the presence of simulated body fluid having a common pH of 7.25 similar to human blood plasma. The scanning electron microscopy and X-ray diffraction were used for characterization of microstructures and phase composition of coating respectively. Results have shown that HA coating obtained at 230 mm stand-off distance exhibits hardness and anti-wear characteristics as compared to coatings with stand-off distance of 180mm and 280 mm. This may be attributed to lower porosity and dense structure at a stand-off distance of 230 mm. The main wear mechanisms on the coating’s wear track were found to be abrasive and adhesive.
      KeywordsWPlasma sprayed hydroxyapatite coating, Stand-off distance, Microstructure, Sliding wear in Simulated Body Fluid, Mechanical properties

      DOI :10.24874/ti.1054.02.21.06
      PubDate: 15 March 2022 12:00:00 +0100
  • Erosion Modeling of Coated Gate Valves

    • Abstract:
      Authors Jong Hyok Ri, Razvan George Ripeanu, Alin Dinita
      This paper aims to evaluate the erosion wear in coated valves where multiphase fluids containing oil and sand flow. Analysis models to evaluate the erosion rate of gate valves coated and uncoated with Everslik 1301 by using COMSOL Multiphysics 5.4 are presented. Also, based on these models, analysis results performed compare the erosion rates of coated and uncoated gate valves and evaluate the effect of the film thickness on the erosion rate. Finnie and Oka models were used to evaluate the erosion rate of the valve elements.
      KeywordsGate valve, Lubrication film, Erosion, Solid particles, Turbulent flow

      DOI :10.24874/ti.1145.06.21.09
      PubDate: 15 March 2022 12:00:00 +0100
  • An Experimental Study of Forced Vibration Influence on Disc Brake Drag
           Torque in Heavy Commercial Road Vehicles

    • Abstract:
      Authors Pontus Fyhr, Rikard Hjelm, Jens Wahlström
      Drag torque in a disc brake is the residual torque when the brake is not activated. This torque can adversely influence the total energy consumption, life of the brake components, and level of airborne wear particles from vehicles. Drag torque is of special interest for long haul trucking since it could have an effect of the total energy consumption. Drag torque performance of a disc brake is usually evaluated with conventional inertia dynamometers. Vibrations induced by the wheel can help to retract the pads from the disc and decrease the drag torque. It is hard to study this phenomenon with conventional inertia dynamometers since there is usually no system to induce a forced vibration on the brake. Therefore, the aim of the paper is to investigate the effect of vibrations on the drag torque for a commercial vehicle disc brake with a novel test setup. This is done by comparing test run with and without pads, forced vibrations, and pad retraction springs. The results indicate that the forced vibrations strongly affect the level of measured drag torque. In addition, the introduction of a retraction spring can reduce drag torque with more than 50% when vibrations are induced.
      KeywordsDrag torque, Disc brake, Testing vibrations, Heavy commercial vehicles

      DOI :10.24874/ti.1132.06.21.09
      PubDate: 15 March 2022 12:00:00 +0100
  • Abrasive Wear Resistance of Electrospark Coatings on Titanium Alloys

    • Abstract:
      Authors Mara Kandeva, Georgi Kostadinov, Todor Penyashki, Valentin Kamburov, Rayna Dimitrova, Seryoja Valcanov, Antonio Nikolov, Blagoj Elenov, Mikhail Petrzhik
      According to most researchers, improving the tribological characteristics of titanium alloys at this stage is most appropriate through surface modification tribotechnologies. In the present work, the qualitative characteristics of coatings of tungsten-free hard alloy materials materials based on TiC, TiN TiCN TiB2, applied on the most popular titanium alloy Ti6Al4V by electrospark deposition with low pulse energy are investigated. The influence of the electrode materials, the process parameters, the characteristics of the coatings and the roughness parameters on their wear and abrasion resistance has been studied. It was found that the use of coatings from the studied electrodes shows an increase in abrasion resistance by 1.5 - up to 3 times compared to that of the substrate and the electrode materials and process parameters were determined, in which maximum wear resistance was obtained.
      KeywordsWear resistance, Electrospark deposition, Titanium alloys, Coatings, Roughness

      DOI :10.24874/ti.1143.06.21.09
      PubDate: 15 March 2022 12:00:00 +0100
  • Locally Resolved Residual Stress Measurements in (Al,Ti)N Coatings Using
           Raman Spectroscopy

    • Abstract:
      Authors Bernd Breidenstein, Nils Vogel, Harald Behrens, Marcel Dietrich, Jon M. Andersson
      The residual stress state in tool coatings can positively influence tool life. Measurement in strongly curved surfaces e.g. in the cutting edge area is only possible to a limited extent by means of X-ray diffraction (XRD). Raman spectroscopy offers great potential for determining the residual stress state in this area. Therefore, the aim is to determine the fundamental limits of residual stress measurement by XRD on coated carbide tools and to determine and evaluate the suitability of Raman spectroscopy. On typical cutting tools only a small area on the rake face can provide reliable measurement results using conventional XRD methods. Using the XRD results as reference, Raman spectroscopy shows plausible results for residual stresses induced into the coating by mechanical or thermal post-treatment. Coating-induced residual stresses cannot be reliably detected because other coating properties are also changed by modified coating processes that induce higher compressive residual stresses.
      KeywordsResidual stress, PVD, Coating, Raman-spectroscopy, Titanium aluminum nitride, X-ray diffraction

      DOI :10.24874/ti.1144.06.21.08
      PubDate: 15 March 2022 12:00:00 +0100
  • A Review of Mixed Lubrication Modelling and Simulation

    • Abstract:
      Authors Ruchita Patel, Zulfiqar Ahmad Khan, Adil Saeed, Vasilios Bakolas
      Majority of the rolling contacts applied in complex interacting machine elements for example bearings and gears perform under Mixed Lubricating (ML) conditions, where the lubricant film can’t fully separate the asperities of the two contacting surfaces. Highly loaded, interacting asperity surrounded with lubricant film, leads to the development of surface originated defects such as scuffing, micropitting, and wear in the ML region. This region exists amid Elastohydrodynamic Lubrication and Boundary Lubrication which needs consolidated knowledge of fluid film and direct contact of asperities, this makes the problem more difficult to solve numerically. Numerous authors have used the Reynolds equation or its modified versions to solve the lubrication problem numerically. However, still, some uncertainty is there to model mixed lubrication operating conditions, with traditional Reynold’s equation, because the assumptions commonly made in Elastohydrodynamic lubrication are not valid within the context of mixed lubrication regime. In this paper previously, used models for mixed lubrication have been examined, and various development in related fields are discussed. Therefore, this review will provide an integrated, synthesized overview of the topic and in turn will lead to benefits for wide-ranging academic, industrial and research communities.
      KeywordsRolling contact, Mixed Lubrication, Lubrication Modelling, Simulation

      DOI :10.24874/ti.1186.09.21.11
      PubDate: 15 March 2022 12:00:00 +0100
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