Advances in Tribology最新文献

{"title":"Wear Resistance of (Diamond-Ni)-Ti6Al4V Gradient Materials Prepared by Combined Selective Laser Melting and Spark Plasma Sintering Techniques","authors":"R. Rahmani, M. Antonov, L. Kollo","doi":"10.1155/2019/5415897","DOIUrl":"https://doi.org/10.1155/2019/5415897","url":null,"abstract":"An approach of sintering 3D metal printed lattices and diamond nickel-coated particles is proposed which can be used for the production of tunnel boring machine (TBM) cutters and mining equipment blades. Nickel-coated diamond particles are mixed with titanium powder and incorporated into a lightweight Ti6Al4V (3D printed) lattice with the help of spark plasma sintering (SPS) method. Effect of Ti6Al4V lattices size, diamond particles size, and nickel coating layer thickness on wear resistance of composites is discussed. Functionally graded lattice (FGL) structures were produced by selective laser melting (SLM) method, representing an increasingly growing additive manufacturing engineering area introduced in material engineering. Impact-abrasive tribo-device (IATD), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and optical surface profiler (OSP) were used to characterize samples. An ab initio design of diamond-metal composite is based on the improvement of impact and abrasive wear resistance of Ti6Al4V by adding diamond particles and by applying of gradient lattice structure. The specimen with larger size of the diamond particle and thicker Ni coating has better wear resistance. In addition, ANSYS software simulations were done to analyze the effect of the presence of 3D printed lattice via nonlinear finite element AUTODYN solver under impact test. Diamond-based gradient composite material produced by combined SLM-SPS methods can be applied in applications where resistance against impact-abrasive wear is important.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/5415897","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41870385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Experimental Study of Tribo-Mechanical Performance of Low-Temperature PVD Based TiN Coated PRCL Systems for Diesel Engine","authors":"G. Uddin, Muhammad Sajid Kamran, J. Ahmad, M. Ghufran, M. Asim, Muhammad Qasim Zafar, M. Irfan, B. Waseem, A. Khan, M. Jawad, I. Zeid, S. Kamarthi","doi":"10.1155/2018/9437815","DOIUrl":"https://doi.org/10.1155/2018/9437815","url":null,"abstract":"Piston ring and cylinder liner (PRCL) interface is a major contributor to the overall frictional and wear losses in an IC engine. Physical vapor deposition (PVD) based ceramic coatings on liners and rings are being investigated to address these issues. High temperature requirements for applications of conventional coating systems compromise the mechanical properties of the substrate materials. In the current study, experimental investigation of tribo-mechanical properties is conducted for various titanium nitride (TiN) coated PRCL interfaces in comparison with a commercial PRCL system. Low-temperature PVD based TiN coating is successfully achieved on the grey cast iron cylinder liner samples. Surface roughness of the grey cast iron cylinder liner substrates and the thickness of TiN coating are varied. A comprehensive comparative analysis of various PRCL interfaces is presented and all the trade-offs between various mechanical and tribological performance parameters are summarized. Coating thickness between 5 and 6 micrometres reports best tribo-mechanical behaviour. Adhesion and hardness are found to be superior for the TiN coatings deposited on cylinder liner samples with higher roughness, i.e., ~ 5-micron Ra. Maximum 62 % savings on the COF is reported for a particular PRCL system. Maximum 97% saving in cylinder liner wear rate is reported for another PRCL system.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/9437815","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43249335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Analysis of Elastic Contact between Coated Bodies","authors":"S. Spinu","doi":"10.1155/2018/6498503","DOIUrl":"https://doi.org/10.1155/2018/6498503","url":null,"abstract":"Substrate protection by means of a hard coating is an efficient way of extending the service life of various mechanical, electrical, or biomedical elements. The assessment of stresses induced in a layered body under contact load may advance the understanding of the mechanisms underlying coating performance and improve the design of coated systems. The iterative derivation of contact area and contact tractions requires repeated displacement evaluation; therefore the robustness of a contact solver relies on the efficiency of the algorithm for displacement calculation. The fast Fourier transform coupled with the discrete convolution theorem has been widely used in the contact modelling of homogenous bodies, as an efficient computational tool for the rapid evaluation of convolution products that appear in displacements and stresses calculation. The extension of this technique to layered solids is tantalizing given that the closed-form analytical functions describing the response of layered solids to load are only available in the frequency domain. Whereas the false problem periodization can be treated as in the case of homogenous solids, the aliasing phenomenon and the handling of the frequency response function in origin require adapted techniques. The proposed algorithm for displacement calculation is coupled with a state-of-the-art contact solver based on the conjugate gradient method. The predictions of the newly advanced computer program are validated against existing results derived by a different method. Multiple contact cases are simulated aiming to assess the influence of coating thickness and of its elastic properties on the contact parameters and the strass state. The performed simulations prove that the advanced algorithm is an efficient tool for the contact analysis of coated bodies, which can be used to further understand the mechanical behavior of the coated system and to optimize its design.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/6498503","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43231016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Size of Multiwalled Carbon Nanotubes Dispersed in Gear Oils for Improvement of Tribological Properties","authors":"Kodanda Ramarao Chebattina, V. Srinivas, N. M. Rao","doi":"10.1155/2018/2328108","DOIUrl":"https://doi.org/10.1155/2018/2328108","url":null,"abstract":"The aim of the paper is to investigate the effect of size of multiwalled carbon nanotubes (MWCNTs) as additives for dispersion in gear oil to improve the tribological properties. Since long pristine MWCNTs tend to form clusters compromising dispersion stability, they are mildly processed in a ball mill to shorten the length and stabilized with a surfactant before dispersing in lubricant. Investigations are made to assess the effect of ball milling on the size and structure of MWCNTs using electron microscopy and Raman spectroscopy. The long and shortened MWCNTs are dispersed in EP 140 gear oil in 0.5% weight. The stability of the dispersed multiwalled carbon nanotubes is evaluated using light scattering techniques. The antiwear, antifriction, and extreme pressure properties of test oils are evaluated on a four-ball wear tester. It is found that ball milling of MWCNTs has a strong effect on the stability and tribological properties of the lubricant. From Raman spectroscopy, it is found that ball milling time of up to 10 hours did not produce any defects on the surface of MWCNTs. The stability of the lubricant and the antiwear, antifriction, and extreme pressure properties have improved significantly with dispersion shortened MWCNTs. Ball milling for longer periods produces defects on the surface of MWCNTs reducing their advantage as oil additives.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/2328108","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47225852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Partial Contact of a Rigid Multisinusoidal Wavy Surface with an Elastic Half-Plane","authors":"I. Tsukanov","doi":"10.1155/2018/8431467","DOIUrl":"https://doi.org/10.1155/2018/8431467","url":null,"abstract":"The interaction effects, arising at partial contact of rigid multisinusoidal wavy surface with an elastic half-plane, are considered in the assumption of continuous contact configuration. The analytical exact and asymptotic solutions for periodic and nonperiodic contact problems for wavy indenters are derived. Continuous contact configuration, appearing at small ratios of amplitude to wavelength for cosine harmonics, leads to continuous oscillatory contact pressure distribution and oscillatory relations between mean pressure and a contact length. Comparison of periodic and nonperiodic solutions shows that long-range elastic interaction between asperities does not depend on a number of cosine wavelengths.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/8431467","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47660892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Contact Mechanics of Novikov’s Surface-Hardened Gearing during Running-in Process","authors":"A. Beskopylny, N. Onishkov, V. Korotkin","doi":"10.1155/2018/9607092","DOIUrl":"https://doi.org/10.1155/2018/9607092","url":null,"abstract":"The article is devoted to the analysis of the state of the contact surfaces of the higher kinematic pair in the general case of relative motion, that is, in the presence of rolling, sliding, and twisting, which is characteristic of Novikov’s circular-screw gears. The purpose of the work is to assess the impact of friction forces, the state of contact surfaces after tool processing, and the localization of the instantaneous contact spot on the level of contact—fatigue durability of gears. Power contact in the presence of geometric slippage of the mating surfaces leads to a significant change in the initial geometry and the mechanical properties of surface layers. In the existing methods of calculations of contact strength, the effect of running-in is investigated insufficiently, which leads to an incorrect result, especially for gear with high hardness of the teeth. In this work, the conditions of contact interaction close to the real requirements are studied on the basis of experimental material, numerical solution of the contact problem, determination of the terms of the contact areas of slip, and adhesion within the instantaneous spot. The shape of the instant contact spot has asymmetry and can be approximated by an ellipse with the introduction of a correction factor. The running-in period is of a plastic nature with cold deformation and reduction of the roughness of surfaces. As a result of the run-in period, the area of actual contact (tooth height) is increased by 2 or more times. It is not desirable to spread the area of contact at the area of adhesion that initiates the formation of pitting. The presence of defective surface area on the level of contact strength does not have significant influence, because of the running-in period, but increases the risk of spalling and brittle fracture.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/9607092","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43035323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Study of Hydromagnetic Longitudinal Rough Circular Step Bearing","authors":"J. V. Adeshara, M. Prajapati, G. Deheri, R. Patel","doi":"10.1155/2018/3981087","DOIUrl":"https://doi.org/10.1155/2018/3981087","url":null,"abstract":"This article discusses the effect of longitudinal roughness on the performance of hydromagnetic squeeze film in circular step bearing. To characterize the random roughness of the bearing surfaces the stochastic model of Christensen and Tonder has been employed. The stochastically averaged Reynolds’ type equation is solved using suitable boundary conditions to obtain the pressure distribution and then the load bearing capacity is computed. The results are presented in graphical form. The graphical results presented here establish that the hydromagnetic lubrication offers significant help to the longitudinal roughness pattern to enhance the performance of the bearing system. Of course, conductivities of the plates, standard deviation, and the supply pressure contribute towards reducing the negative effect induced by variance (+ve) and skewness (+ve).","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/3981087","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43822736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Novel Analytical Method to Calculate Wheel-Rail Tangential Forces and Validation on a Scaled Roller-Rig","authors":"N. Bosso, Nicolò Zampieri","doi":"10.1155/2018/7298236","DOIUrl":"https://doi.org/10.1155/2018/7298236","url":null,"abstract":"The study of railway dynamic strongly depends on the estimation of the tangential forces acting between wheel and rail. Simulation of the dynamical behaviour of railway vehicles is often performed using multibody codes, and the calculation of the contact forces must be efficient and accurate, even if the contact problem is strongly nonlinear. Therefore, the contact problem is still of great interest for researchers. This work proposes an analytical and efficient algorithm to calculate wheel-rail tangential forces. The proposed method is compared with the most commonly used algorithms under different conditions. In addition, experimental tests are performed on a scaled prototype on roller-rig to demonstrate that the method can be easily adjusted using experimental results. The benefit of the proposed method is to provide an analytical and fast solution, able to obtain accurate results and to allow corrections based on empirical evidence.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/7298236","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46831897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Processing and Wear Behaviour of 3D Printed PLA Reinforced with Biogenic Carbon","authors":"Ertan G. Ertane, A. Dorner-Reisel, O. Baran, T. Welzel, Viola Matner, Stefan Svoboda","doi":"10.1155/2018/1763182","DOIUrl":"https://doi.org/10.1155/2018/1763182","url":null,"abstract":"For the first time, biocarbon reinforced polylactide (PLA) filaments were available for the 3D printing. Biocarbon is the carbon obtained from trees, plants, and soils to naturally absorb and store carbon dioxide from the atmosphere. One of the most important features is renewability. Because of this, it has been decided to reinforce PLA with biocarbon to obtain 100% recyclable material. Although PLA has been used in 3D printing for a long time, more applications like housings or structural interior of automobiles or other vehicles can be realised, if the mechanical and tribological properties are improved. Because the new PLA/biocarbon reinforced composites are degradable, they can be used as soil improvement after end of life as a structural material. The filaments were produced by compounding the biocarbon with polylactide granulate. Biocarbon was produced by pyrolysis of wheat stems at 800°C. The biomass were collected from different regions in Germany, Europe. As shown by Raman spectroscopy, the in-plane crystallite size of pyrolysed wheat stems from different regions is almost similar and amounts to 2.35 ±0.02 nm. Biocarbon particles were successfully integrated into the polylactide. Filaments of 1.75 mm diameter were produced for 3D (3-dimensional) printing. Filaments with 5 vol.-%, 15 vol.-%, and 30 vol.-% biocarbon were extruded. The fused deposition modelling (FDM) printing process was slightly hindered at higher biocarbon loading. Based on optical and scanning electron microscopy, a very homogeneous particle distribution can be observed. Single carbon particles stick out of the filament surface, which may be a reason for enhanced nozzle wear during 3D printing. Friction is more stable for 30 vol.-% reinforced PLA in comparison to unreinforced PLA and composites with lower particle fraction. This effect could be caused by some topographical effects due to void generation at the surface of PLA with 30 vol.-% biocarbon. In general, the tribological resistance increases with higher volume fraction of biocarbon.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/1763182","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46507179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tribology and Mechanical Properties of Carbon Fabric/MWCNT/Epoxy Composites","authors":"B. Shivamurthy, K. Murthy, S. Anandhan","doi":"10.1155/2018/1508145","DOIUrl":"https://doi.org/10.1155/2018/1508145","url":null,"abstract":"Cryogenic treated multilayered carbon fabric/oxidized multiwall carbon nanotube/epoxy (CCF/O-MWCNT/E) composite and untreated carbon fabric/epoxy (CF/E) composite were prepared by hot compression molding technique. The density and mechanical properties such as tensile properties, flexural properties, interlaminar shear strength, and microhardness of the composites were investigated as per ASTM standards. The wear and coefficient of friction behavior were investigated using computer interfaced pin-on-disc test rig at room temperature for varied load and sliding speed. The morphology of worn surfaces of the wear test composite specimens were studied by scanning electron microscope. It is found that the synergetic effect of addition of O-MWCNT to epoxy matrix and cryogenic treatment of carbon fabric improved the wear resistance and mechanical properties. Also, a thin lubricating film developed by the oxidized multiwall carbon nanotube/epoxy wear debris reduces the coefficient of sliding friction and wear rate.","PeriodicalId":44668,"journal":{"name":"Advances in Tribology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2018-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2018/1508145","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42422749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}