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1 – 10 of 32Abdul Munir Hidayat Syah Lubis, Bambang Ariwahjoedi and Mustafar Sudin
This study aims to characterize the composition of the tribo-layer formed during sliding of steel in the presence of crude jatropha oil (CJO) and epoxidized jatropha oil (EJO…
Abstract
Purpose
This study aims to characterize the composition of the tribo-layer formed during sliding of steel in the presence of crude jatropha oil (CJO) and epoxidized jatropha oil (EJO) under boundary lubricant application.
Design/methodology/approach
CJO was obtained from a local market and used as received. EJO was obtained by epoxidation process with peroxyformic acid catalyzed by acidic ion exchange resin. The tribological test was conducted by the four ball method according to ASTM 4192. Wear scars generated on the lower balls were used to characterize the tribo-layer. Energy-dispersive X-ray and X-ray photo spectroscopy analysis were conducted to characterize the tribo-layer composition.
Findings
EJO shows a lower friction coefficient compared to CJO. Moreover, EJO also shows better wear preventive properties compared to CJO. The oxidation of CJO and EJO has lead chemisorption of the oil to steel surface to cause formation of protective layers for the steel surface. The layers were constructed from inorganic oxide in the form of iron oxides and silicon oxide together with organic layers in form of aldehyde, ketone and carboxylic acid. The formation and removal of this layer from rubbing sites are considered to affect wear-preventive and friction behaviour of steel lubricated with CJO and EJO.
Originality/value
This works highlights friction and anti-wear characteristics of CJO and EJO. This work also presents the composition of the tribo-layer that formed because of the sliding of steel lubricated with CJO and EJO. The method and result can be used for further investigation and development of lubricant.
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Ramazan Karslioğlu, Hatem Akbulut, Mehmet Uysal and Guray Bağdatli
The objective of the present investigation is to prepare a Zn–Al matrix (73 wt. per cent Zn + 27 wt. per cent Al) reinforced with SiC and graphite (Gr) hybrid composites by a…
Abstract
Purpose
The objective of the present investigation is to prepare a Zn–Al matrix (73 wt. per cent Zn + 27 wt. per cent Al) reinforced with SiC and graphite (Gr) hybrid composites by a rapid current sintering technique. Well-known Zn-based alloys are good candidates for load bearing applications. However, some limitations exist in Zn sublimation during casting and solid-state sintering and low-sliding velocity applications. The purpose is to develop new hybrid composites for self-lubricated bearing alloys by the facile production technique of current-activated sintering for these types of hybrid composites at very short sintering periods.
Design/methodology/approach
Designing a special power unit for current sintering. The hybrid composites of the Zn–Al matrix were reinforced with 20 vol. per cent SiC and different amounts of Gr (2.5, 5.0, 7.5 and 10 weight per cent) and sintered rapidly by current sintering. Tribological tests for wear behaviors and self-lubrication effect were studied. The authors' approach is mainly to produce low-cost load-bearing materials.
Findings
Successful and rapid production of Zn–Al alloy SiC/Gr hybrid composites in this study led to increasing load bearing capacity, decreasing friction coefficient and wear rate and production of good substitutes for conventional bearing applications.
Originality/value
A conventional Zn alloy was reinforced with both SiC and Gr particles. This work is original in two ways. It is noted after the literature survey that this alloy is first reinforced with two different types of reinforcements as a hybrid type of composite. Second, the consolidation of this hybrid material was carried out by a direct current for eliminating Zn sublimation and shortening the production time. In tribological applications demanding strength and lubrication requirements, Zn–Al/SiC/Gr hybrid composites were assessed as good substitutes for conventional materials owing to improved wear resistance as a result of combined reinforcement of SiC and Gr particulates.
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Kanagaraj M., Babu S., Sudhan Raj, Jonah N., Gusztáv Fekete and Christy T.V.
The main purpose of this study in the field of automotive brake friction material is to find an effective material to replace the environmentally hazardous copper in the brake pad…
Abstract
Purpose
The main purpose of this study in the field of automotive brake friction material is to find an effective material to replace the environmentally hazardous copper in the brake pad formulation.
Design/methodology/approach
Cu is used as functional filler in various forms in the friction material formulation. Because of its hazardous impact to the aquatic life, a suitable replacement of Cu is the main focus of this research. Three novel friction composite materials using ground granulated blast furnace slag (GGBFS) as a suitable alternative for Cu were developed by increasing its Wt.% from 5% to 15% in the step of 5%.
Findings
The physical, mechanical and chemical properties of the developed friction composites were tested as per the industrial standards. The tribological properties were analyzed as per SAE J661 standard using the chase test rig. Initial studies revealed that the friction composite having 5% GGBFS exhibited better physical, mechanical and chemical properties with excellent frictional performance having minimal fluctuations even at higher temperatures. Nonetheless, the results showed that the friction composite containing 15 Wt.% GGBFS revealed a better wear resistance property compared with the other two composites due to the tribo lubricating layer formation at the frictional interface. Scanning electron microscope analysis was performed to understand the wear mechanism and tribo layer formations through topography studies.
Originality/value
This paper explains the influence of GGBFS as a replacement of barytes in brake pads formulation to enhance the tribological performance.
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Aleksandar Vencl, Ilija Bobic and Blaza Stojanovic
Aluminium alloys are frequently applied in automotive and other industries, since they provide mass reduction. Besides positive effects, aluminium alloys have their shortcomings…
Abstract
Purpose
Aluminium alloys are frequently applied in automotive and other industries, since they provide mass reduction. Besides positive effects, aluminium alloys have their shortcomings reflected, first of all, in inappropriate tribological properties of these materials. The aim of this research was to enable the production of cheap aluminium alloy matrix composite with favourable combination of structural, mechanical and tribological properties, focusing on the tribological behaviour.
Design/methodology/approach
The A356 Al-Si alloy was used as a matrix for producing metal matrix composites in compocasting process. Three different materials, in form of particles, were added to the matrix (Al2O3, SiC and graphite). Hardness and tribological properties (wear, friction and wear mechanism) of heat-treated (T6) samples were examined and compared. Tribological tests were carried out on ball-on-block tribometer under dry sliding conditions. Sliding was linear (reciprocating). Counter body was alumina ball. Average velocity was 0.038 m/s (max. 0.06 m/s), sliding distance was 500 m and normal load was 1 N.
Findings
The effect of two different ceramic particles and graphite particles on tribological properties of obtained composites was evaluated. Wear resistance of composites reinforced with SiC particles was higher and coefficient of friction was lower compared to the composite reinforced with Al2O3 particles. A dual hybrid composite (with SiC and graphite particles) showed the lowest value of wear rate and friction coefficient. Dominant wear mechanism for all tested material was adhesion.
Research limitations/implications
It seems useful to continue the work on developing hybrid composites containing soft graphite particles with A356 Al-Si alloy as matrix. The major task should be to improve particles distribution (especially with higher graphite content) and to explore tribological behaviour in diverse working conditions.
Originality/value
Particulate composites with A356 aluminium alloy as a matrix produced in compocasting process using ceramic particles (Al2O3, SiC) were investigated in many researches, but there are only few detailed analyses of dual composites (with the addition of ceramic and graphite particles). In some previous studies, it was shown that compocasting process, as relatively cheap technology, can obtain good structural and mechanical characteristics of composites. In this study, it was shown that even a low graphite content, under specified conditions, can improve tribological properties.
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This study aims to determine the braking performance of limestone as a filler in brake friction materials.
Abstract
Purpose
This study aims to determine the braking performance of limestone as a filler in brake friction materials.
Design/methodology/approach
Samples containing limestone material (30-35-40%), which can be an alternative to brake friction material filler, were produced. The samples were weighed on precision scales, mixed homogeneously and produced using the hot molding method. The physical and tribological properties of the produced samples were determined, and their microscopic analyzes were made with scanning electron microscopy.
Findings
As the amount of limestone increased, the density of the samples decreased. The friction coefficient and wear rates were close to each other and within the optimum limits for all samples. Limestone materials can be used instead of barite materials studied in the literature on brake linings. Microcracks were observed only in samples containing 30% and 35% limestone in microscopic images.
Originality/value
In this study, the wear rate, coefficient of friction and microstructures on the friction surfaces of brake friction materials containing limestone were investigated. The usability of limestone as a filler in brake friction materials provides valuable information to researchers and industrial organizations in the brake friction material field.
Lokanadham Dharmana and Venkata Subbaiah Kambagowni
This study aims to develop the Al-Si-Mg metal matrix composite, reinforced distinctly with lime stone powder (LSP; 12% by weight) and Al2O3 (12% by weight), and compare their…
Abstract
Purpose
This study aims to develop the Al-Si-Mg metal matrix composite, reinforced distinctly with lime stone powder (LSP; 12% by weight) and Al2O3 (12% by weight), and compare their mechanical properties and tribological performance.
Design/methodology/approach
The composites are fabricated through stir casting process. In view of the previous work, the Al-LSP composite with LSP reinforcement (12 Wt.%) shows enhanced mechanical properties and tribological performance, as compared with other weight percentages.
Findings
Though the Al-LSP composite is less expensive, it shows similar hardness, tensile strength and specific strength, when compared with Al- Al2O3 composite. However, the Al-LSP composite exhibits significant enhancement of above three properties, when compared with Al-Si-Mg metal. The systematic factorial design of experiments is obtained through Taguchi OA [L9]. The tribological performance is estimated through wear rate (WR-mm3/m) and coefficient of friction (CF) by varying the operating parameters of sliding distance (SD), load (L) and sliding velocity (SV). According to ANOVA results, the optimal condition of WR for all the tested materials is L1SD3SV1. Further, the optimal condition of CF is L1SD1SV3 for Al-LSP and Al-Si-Mg metal, while L2SD3SV2 is for Al-Al2O3 composite. The regression equation predicts the measured experimental values within error band of ± 8 percentage.
Originality/value
A comparison of two composite materials (Al-LSP and Al-Al2O3) with same weight fractions (12%) shows almost same trend in both the mechanical and tribological testing process. However, the developed Al-LSP composite exhibited better properties than the Al-Al2O3 and Al-base. Therefore, Al-LSP can be suggested for automotive applications (i.e., connecting rod, cylinder liners, camshaft) and structural applications (such as frames, over hanging supports), without compromising in desirable original with properties of constituents in the new material, which is achievable for looking to the end uses.
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Qian Wang, Biao Ma, Liang Yu, Man Chen, Guoyu Wang and Liangjie Zheng
This paper aims to explore the influence of applied pressure on the tribological properties of the friction component in a wet multi-disc clutch during the running-in process.
Abstract
Purpose
This paper aims to explore the influence of applied pressure on the tribological properties of the friction component in a wet multi-disc clutch during the running-in process.
Design/methodology/approach
The running-in evolutionary was explored in terms of global friction performance. The variation of friction torque and mean COF of the initial 300 engagement cycles was obtained by full-scale tests. Finally, an optical microscope was used to detect the wear characteristics of friction surfaces.
Findings
The applied pressure showed a significant influence on the tribological behaviors of wet clutches during the running-in process. The mean COF decreased and then increases with the increase of the applied pressure. A higher applied pressure contributed to more asperity summits being sheared, thus resulting in a smoother surface. Considering a suitable wore performance, properly applied pressure is necessary.
Originality/value
The results provide theoretical guidance for selecting the optimal applied pressure in the running-in of wet clutches.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2022-0256/
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Kanagaraj M., Babu S., Sudhan Raj Jegan Mohan and Christy T.V.
This study aims to compare the friction and wear performance of commercial brake pads for four wheelers among metallic, semimetallic and non-asbestos organic (NAO) formulations to…
Abstract
Purpose
This study aims to compare the friction and wear performance of commercial brake pads for four wheelers among metallic, semimetallic and non-asbestos organic (NAO) formulations to identify one with the right combination of properties for optimal performance.
Design/methodology/approach
Three commercially available brake pads for four-wheeler automotive applications were acquired. Samples were cut from the brake pads to study their physical and mechanical properties. The effects of friction and wear were analyzed using a pin-on-disk tribotester. Surface morphology on the worn-out surface of the brake pads was studied.
Findings
It was observed that the frictional properties remained stable and less fluctuating in the semimetallic and NAO pads, whereas the coefficient of friction of all the pads varied between 0.35 and 0.55. The wear rate of the metallic pads is less than that of NAO and semimetallic pads. The surface morphology studies revealed that the metallic pads contained more primary plateaus and smaller amounts of secondary plateaus compared to semimetallic and NAO pads, resulting in better wear resistance characteristics.
Originality/value
Because the market is flooded with various options for brake pad materials, it is imperative that the vehicle manufacturers choose the right pad material with great care not only to ensure the optimal functioning of the braking system but also passenger safety. Mechanical and tribological properties of brake pads contribute greatly to their effectiveness. There is a requirement to choose the proper material for a certain application that has a consistent friction coefficient and reduced wear.
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Jibin T. Philip, Deepak Kumar, S.N. Joshi, Jose Mathew and Basil Kuriachen
Electrical discharge machining (EDM) is well-known for its credibility in the processing of advanced materials, which are electrically conductive. The strenuous effort associated…
Abstract
Purpose
Electrical discharge machining (EDM) is well-known for its credibility in the processing of advanced materials, which are electrically conductive. The strenuous effort associated with machining of Ti6Al4V (Ti64) using conventional methods, and its low tribological behavior, present an immediate need to develop solutions to monitor and improve the compatible techniques such as EDM.
Design/methodology/approach
The present work includes following: monitoring the ED process parameters, namely, current (I) and pulse on time (Ton), in controlling the material removal rate and surface roughness (Ra and Sa) for development of tribo-adaptive surfaces; and investigation on the role of oxides pertinent to the tribo-behavior of Ti64 (bare and EDMed) surfaces.
Findings
The tribological behavior of Ti6Al4V surfaces got remarkably improved through ED machining, which points to the credibility of the process to establish itself as a surface alloying technique. The recast layer (RL, alloyed matrix) acted as a protective coating; stable enough to assist the developed tribo-oxides such as TiO and Ti8O15 in rendering improved sliding performance at load = 50 N and speed = 0.838 ms−1.
Originality/value
The surface modification through ED machining was experimentally proven to improve the wear behavior of Ti6Al4V surfaces.
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Zhengfeng Cao, Yanqiu Xia, Chuan Chen, Kai Zheng and Yi Zhang
This paper aims to explore polyaniline (PANI) as a lubricant additive to improve the anti-corrosion and tribological properties of ionic liquids (ILs) for actual applications.
Abstract
Purpose
This paper aims to explore polyaniline (PANI) as a lubricant additive to improve the anti-corrosion and tribological properties of ionic liquids (ILs) for actual applications.
Design/methodology/approach
ILs were synthesized by dissolving lithium salts in synthetic oil and were used as a base oil to prepare ILs-based greases. PANI was used as an additive. The tribological properties were investigated in detail and the anti-corrosion ability was also assessed via salt spray test. After friction test, the worn surfaces were characterized by scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy to analyze the lubrication mechanisms.
Findings
PANI not only reduces the corrosion but also improves the friction reduction and anti-wear abilities of the ILs-based greases. The analysis indicates that the protective films generated on the worn surfaces were responsible for the preferable anti-corrosion and tribological properties.
Originality/value
This paper provides an effective approach to improve the anti-corrosion and tribological properties of ILs for actual applications.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0469/
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