On the Effect of Roller Materials on the Power Window Mechanism From a Tribological Perspective

Author(s):  
S. B. Chee ◽  
Ammar Al Shalabi ◽  
C. W. Chin ◽  
B. F. Yousif

This study serves to delineate the effects of material on the lifespan of a polymeric roller rubbing against a steel wire. Four materials, namely nylon, polyester, borosilicate glass and epoxy are the manipulated variables in conducting a simulation with a steel wire. A block-on-ring machine was used to conduct the tribo-experiments under dry contact condition. In concurrence with average operating conditions, the machine was set to 0.15 m/s sliding velocity, at an applied load of 10 N. Worn surfaces of the polymer were subsequently studied under optical microscopy. Frictional and wear resistance results were presented versus time for a predetermined duration. There is a strong correlation between the wear resistance and material hardness but the contrary is found with elongation at break. Findings revealed better wear resistance in epoxy due to its higher hardness. The improvement attained with reference to nylon was approximately 68%. The optical images of worn surfaces which sustained scratches and grooves implied that the contact mechanism was that of abrasion.

2008 ◽  
Vol 15 (04) ◽  
pp. 355-360
Author(s):  
SU BE CHEE ◽  
AMMAR AL SHALABI ◽  
B. F. YOUSIF

Steel wires are implemented in numerous systems and undergo frequent faults due to tribological loading conditions. Therefore, this paper presents a study on the tribological performance of steel wire sliding against different counterfaces, namely, aluminum alloy, stainless steel, and mild steel using a block-on-ring tribo-tester. According to common mechanisms, the tests were performed under 5 N applied load and 0.15 m/s sliding velocity under dry contact condition. Additionally, scanning electron microscopy was used to examine the damaged features on the worn surfaces of the steel wire. Weight loss and friction coefficient results were presented versus sliding distances (0–1.6 km). In general, the results showed that friction coefficient did not reach the steady state due to the transformation of the wear mechanism from adhesive to abrasive mode. Nevertheless, the average of friction coefficient was found to be about 0.7 ± 0.1 for stainless steel and 0.2 ± 0.1 for mild steel. Weight loss gradually increased with the increase of sliding distance. The micrographs of worn surfaces revealed that the contact mechanism was transformed from adhesive to abrasive wear mode as implied by the scars and grooves on the wire surface.


2012 ◽  
Vol 557-559 ◽  
pp. 534-537 ◽  
Author(s):  
Yong Ping Niu ◽  
Sa Li ◽  
Jun Kai Zhang ◽  
Li Hua Cai ◽  
Yong Zhen Zhang

Polytetrafluoroethylene (PTFE) nanocomposites filled with alumina nanoparticles were prepared by compression molding and follow-up sintering. The tribological behaviors of PTFE nanocomposites sliding against GCr15 steel were evaluated using ball-on-disk tribology test rig. The worn surfaces of the unfilled and filled PTFE nanocomposite were investigated using a scanning electron microscope (SEM). The wear behavior of the PTFE nanocomposites was explained in terms of the topography of worn surfaces. It was found that the addition of alumina nanoparticles was effective in enhancing the wear resistance of the PTFE nanocomposite.


2021 ◽  
Vol 901 ◽  
pp. 193-198
Author(s):  
Yuh Ping Chang ◽  
Li Ming Chu ◽  
Chien Te Liu ◽  
Jin Chi Wang ◽  
Gao Wei Chen

Due to the booming development of the automation industry and the transportation industry, the mechanical components are prone to wear under long-term operating conditions. To improve the wear resistance, effects of the rolling directions on wear of the aluminum alloys are studied. An optical microscope is used to analyze the crystal phase, and the correlation between the crystal grains and the rolling direction is studied. This study can therefore establish a key technology for improving the wear resistance of aluminum alloys.


Author(s):  
Л.Б. Леонтьев ◽  
Н.П. Шапкин ◽  
А.Л. Леонтьев ◽  
В.Н. Макаров ◽  
А.В. Арон

Повышение долговечности трибосопряжений судовых дизелей, определяющих их ресурс, представляет собой актуальнейшую проблему, обусловленную как безопасностью мореплавания, так и экономическими факторами. Основной причиной отказов коленчатых валов двигателей, определяющих необходимость капитального ремонта, является износ шеек. Решение проблемы повышения износостойкости и, соответственно, долговечности связано с применением трибоактивных присадок в смазку. Несмотря на глубокие и обстоятельные исследования в области применения органо-неорганических материалов для использования в качестве присадок в моторное масло для повышения долговечности трибоузлов осуществить выбор оптимального материала для конкретных условий практически невозможно, так как исследования выполнены для различных условий эксплуатации и по различным методикам. Цель работы – разработка триботехнической присадки к моторным маслам, обеспечивающей повышение надежности и эффективности технической эксплуатации судовыхсреднеоборотных дизелей путем формирования тонкопленочного металлокерамического покрытия на поверхностях трения стальных деталей трибоузлов, позволяющего получить оптимальный комплекс параметров материала износостойкого покрытия. В работе представлены исследования эксплуатационных свойств присадок в моторное масло 17 органо-неорганических триботехнических материалов 4 групп — природные и искусственные полимеры, из которых были изготовлены свыше 20 композиций и композитов. Установлено, что наиболее перспективным является использование нанокомпозитов на основе вермикулита, модифицированного кислотой, в качестве присадок в моторное масло, так как они обладают минимальными коэффициентом трения при граничной смазке (0,007–0,014) а также высокой износостойкостью стали 40Х и обеспечивают минимальную величину скорости изнашивания вкладыша подшипника, благодаря чему повышается ресурс трибосопряжения более, чем в 3 раза, и соответственно снижаются эксплуатационные расходы. Increasing the durability of the tribo-couplings of marine diesel engines, which determine their resource, is an urgent problem due to both the safety of navigation and economic factors. The main reason for engine crankshafts failures, which determine the need for major repairs, is the wear of the necks. The solution to the problem of increasing wear resistance and, accordingly, durability is associated with the use of triboactive additives in the lubricant. Despite in-depth and thorough research in the field of application of organo-inorganic materials for use as additives in engine oil to increase the durability of tribo-nodes, it is almost impossible to choose the optimal material for specific conditions, since the studies were carried out for various operating conditions and according to various methods. The purpose of the work is to develop a tribotechnical additive to motor oils that provides an increase in the reliability and efficiency of technical operation of medium-speed marine diesel engines by forming a thin-film metal-ceramic coating on the friction surfaces of steel parts of tribo-nodes, which allows to obtain an optimal set of parameters of the wear-resistant coating material. The paper presents studies of the operational properties of additives in engine oil of 17 organo-inorganic tribotechnical materials of 4 groups — natural and artificial polymers, from which more than 20 compositions and composites were made. It has been established that the most promising is the use of nanocomposites based on vermiculite modified with acid as additives in engine oil, since they have a minimum coefficient of friction with boundary lubrication (0.007-0.014) as well as high wear resistance of 40X steel and provide a minimum wear rate of the bearing liner, thereby increasing the tribo-tension life by more than 3 times, and, accordingly, operating costs are reduced.


2013 ◽  
Vol 58 (3) ◽  
pp. 973-976 ◽  
Author(s):  
D. Kopyciński ◽  
M. Kawalec ◽  
A. Szczęsny ◽  
R. Gilewski ◽  
S. Piasny

Abstract The resistance of castings to abrasive wear depends on the cast iron abrasive hardness ratio. It has been anticipated that the white cast iron structure will be changed by changing the type of metal matrix and the type of carbides present in this matrix, which will greatly expand the application area of castings under the harsh operating conditions of abrasive wear. Detailed metallographic analysis was carried out to see the structure obtained in selected types of white cast iron, i.e. with additions of chromium and vanadium. The study compares the results of abrasive wear resistance tests performed on the examined types of cast iron.


2018 ◽  
Vol 77 (3) ◽  
pp. 141-148
Author(s):  
M. Yu. Khvostik ◽  
I. V. Khromov ◽  
O. A. Bykova ◽  
G. A. Beresten’

The monitoring of railway rails damage on the railway network of the JSC “Russian Railways” as well as operational and polygon tests are conducted with the purpose of assessing the impact of operating conditions on the intensity of rails damage, obtaining initial data for forecasting rails failures. The increased intensity of rails wear on sites with a complex plan and profile leads to the fact that with a continuous change from the track, rails which have an underutilized service life of more than 20 % are retrieved. Polygon tests on the Test Loop of the JSC “VNIIZhT” near the Scherbinka station can provide the repeatability and reliability of the results, comparative tests are carried out under identical conditions and their duration is several times less than when tested at experimental sites under operational conditions. The results of the polygon tests of new differentially heat-strengthened rails did not reveal any advantages in the wear resistance of special purposed rails (laid in the recommended radius of the curve for its application) when comparing the rails of domestic manufacturers. Metal shelling out on the rolling surface of rails is the main reason for the removal of rails from test batches. The origin and development of defects of this kind is due to both violations of the technology of manufacturing rails, and because of violations of the current maintenance of the track. The metal stock in the area of the rail head of R65 type due to the increase in its dimensions positively affects the extension of the lifetime of the rails, reducing the cost of the life cycle and the rail itself, and the design of the track as a whole. When carrying out a separate study in order to obtain results characterizing the stability of high-quality rails to contact fatigue damage, it is advisable to optimize the conditions of the polygon tests, bringing them closer to operational ones. When forming the test results, it is necessary to expand the list of criteria for assessing the wear resistance of rails, supplementing it with the size of the wear area at the time of a certain operating time of the tonnage, with the introduction of this criterion into the appropriate methods for the polygon (operational) tests.


Author(s):  
A. Martini ◽  
S. B. Liu ◽  
B. Escoffier ◽  
Q. Wang

Understanding and anticipating the effects of surface roughness on subsurface stress in the design phase can help ensure that performance and life requirements are satisfied. The specific approach taken in this work to address the goal of improved surface design is to relate surface characteristics of real, machined surfaces to subsurface stress fields for dry contact. This was done by digitizing machined surfaces, simulating point contact numerically, calculating the corresponding subsurface stress field, and then relating stress results back to the surface. The relationship between surface characteristics and subsurface stress is evaluated using several different approaches including analyses of trends identified through stress field visualization and extraction of statistical data. One such approach revealed a sharp transition between cases in which surface characteristics dominated the stress field and those in which bulk, or global contact effects dominated the stress. This transition point was found to be a function of the contact operating conditions, material properties, and most interestingly, the roughness of the surface.


2013 ◽  
Vol 814 ◽  
pp. 127-134 ◽  
Author(s):  
Liviu Bereteu ◽  
Raul Moisa ◽  
Mihaela Popescu ◽  
Gheorghe Drăgănescu ◽  
Radu Alexandru Rosu ◽  
...  

Applicability of the welded structures in different operating conditions requires experimental research developed in conditions previously imposed for each punctual application. There are analyzed in this case, in terms of vibration testing, some welded joints made with usual tubular steel wire. This is the case of the type carbon steel plates S235 JR according to EN 10025, with a thickness of 3 mm welded with MIG/MAG welding process with R713 tubular wire with a diameter of 1.2 mm, using SelcoNeoMig 3500 equipment. By processing the received signal based on the vibrations response to determine the elastic modulus of the welded structure, which will then be compared both with the modulus value obtained by tensile tests, and with the theoretical value obtained. The results thus obtained will be the basis of design, in optimal conditions of the welded structures regarding the appropriate behavior to the demands imposed.


2016 ◽  
Vol 36 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Mateusz Kotkowiak ◽  
Adam Piasecki ◽  
Michał Kulka

Abstract 100CrMnSi6-4 bearing steel has been widely used for many applications, e.g. rolling bearings which work in difficult operating conditions. Therefore, this steel has to be characterized by special properties such as high wear resistance and high hardness. In this study laser-boriding was applied to improve these properties. Laser alloying was conducted as the two step process with two different types of alloying material: amorphous boron only and amorphous boron with addition of calcium fluoride CaF2. At first, the surface was coated with paste including alloying material. Second step of the process consisted in laser re-melting. The surface of sample, coated with the paste, was irradiated by the laser beam. In this study, TRUMPF TLF 2600 Turbo CO2 laser was used. The microstructure, microhardness and wear resistance of both laser-borided layer and laser-borided layer with the addition of calcium fluoride were investigated. The layer, alloyed with boron and CaF2, was characterized by higher wear resistance than the layer after laser boriding only.


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