scholarly journals Bioinspired microstructures of chitosan hydrogel provide enhanced wear protection

Soft Matter ◽  
2018 ◽  
Vol 14 (11) ◽  
pp. 2068-2076 ◽  
Author(s):  
Jimmy Faivre ◽  
Guillaume Sudre ◽  
Alexandra Montembault ◽  
Stéphane Benayoun ◽  
Xavier Banquy ◽  
...  

Hydrogel bilayer structure leads to different tribological behaviors in terms of friction and wear resistance.

2018 ◽  
Vol 33 (4) ◽  
pp. 501-515
Author(s):  
R Autay ◽  
A Njeh ◽  
F Dammak

The use of polyamide (PA) composites in a variety of thermal conditions can enormously affect their durability that is a very important issue for designers and users. In this study, mechanical and tribological behaviors of PA66 reinforced by various weight fractions of short glass fiber were investigated. All studied materials were subjected to accelerated thermal aging tests. Three-point bending flexural tests were carried out to determine the mechanical behavior. Reciprocating tribotester was employed to determine friction and wear behaviors. Tribological tests were carried out without lubrication and under ambient conditions. Ball on flat contact configuration was adopted for friction tests. Wear tests were carried out against an abrasive counterface. Results showed that flexural strength and elastic modulus increased when increasing glass fiber rate for all tested materials. In the contrary, coefficient of friction and wear resistance decreased. Results showed that the thermal aging increased the flexural features and reduced the coefficient of friction. The effect of thermal aging on the wear resistance depends on the reinforcement rate.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 670
Author(s):  
Gifty Oppong Boakye ◽  
Arna María Ormsdóttir ◽  
Baldur Geir Gunnarsson ◽  
Sandeep Irukuvarghula ◽  
Raja Khan ◽  
...  

The selection of electroless nickel-phosphorus plating (ENP) has been inclined towards their properties and advantages with complex geometry applications. These properties include coating uniformity, low surface roughness, low wettability, high hardness, lubricity, and corrosion- and wear-resistance. Materials used in geothermal environments are exposed to harsh conditions such as high loads, temperature, and corrosive fluids, causing corrosion, scaling, erosion and wear of components. To improve the corrosion- and wear-resistance and anti-scaling properties of materials for geothermal environment, a ENP duplex coating with PTFE nanoparticles was developed and deposited on mild steel within the H2020 EU Geo-Coat project. ENP thin adhesive layer and ENP+PTFE top functional layer form the duplex structure of the coating. The objective of this study was to test the mechanical and tribological properties of the developed ENP-PTFE coatings with varying PTFE content. The microstructural, mechanical and tribological properties of the as-deposited coating with increasing PTFE content in the top functional layer in the order: ENP1, ENP2 and ENP3 were evaluated. The results showed maximum wear protection of the substrates at the lowest load; however, increasing load and sliding cycles increased the wear rates, and 79% increased lubrication was recorded for the ENP2 duplex coating. The wear performance of ENP3 greatly improved with a wear resistance of 8.3 × 104 m/mm3 compared to 6.9 × 104 m/mm3 for ENP2 and 2.1 × 104 m/mm3 for ENP1. The results are applicable in developing low friction, hydrophobic or wear-resistive surfaces for geothermal application.


2018 ◽  
Vol 70 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Shuwen Wang ◽  
Feiyan Yan ◽  
Ao Chen

Purpose The purpose of this paper is to investigate the tribological effects of laser surface texturing (LST) and residual stress on functional surfaces. Design/methodology/approach Three different surface textures (circular dimple, elliptical dimple and groove) with two different textured area ratios (10 and 20 per cent) are designed and fabricated by a Picosecond Nd YAG Laser machine. The friction and wear performance of textured specimens is tested using a UMT-2 friction and wear testing machine in mixed lubrication. Findings Test results show that elliptical dimples exhibit the best performance in wear resistance, circular dimples in friction reduction and grooves in stabilization of friction. The surfaces with larger textured area density exhibit better performance in both friction reduction and wear resistance. The improved performance of LST is the coupled effect of surface texture and residual stress. Originality/value The findings of this study may provide guidance for optimal design of functional surface textures in reciprocating sliding contacts under mixed or hydrodynamic lubrication, which can be used in automotive and other industrial applications.


2011 ◽  
Vol 80-81 ◽  
pp. 60-63
Author(s):  
Xue Qing Yue ◽  
Hua Wang ◽  
Shu Ying Wang

Incorporation of metallic elements, titanium and copper, into carbonaceous mesophase (CM) was performed through mechanical alloying in a ball mill apparatus. The structures of the raw CM as well as the Ti/Cu-added CM were characterized by X-ray diffraction. The tribological behavior of the Ti/Cu-added CM used as lubricating additives was investigated by using a high temperature friction and wear tester. The results show that, compared with the raw CM, the Ti/Cu-added CM exhibits a drop in the crystallinity and a transition to the amorphous. The Ti/Cu-added CM used as lubricating additive displays an obvious high temperature anti-friction and wear resistance effect, and the lager the applied load, the lower the friction coefficient and the wear severity.


2018 ◽  
Vol 70 (9) ◽  
pp. 1706-1713 ◽  
Author(s):  
Guotao Zhang ◽  
Yanguo Yin ◽  
Ting Xie ◽  
Dan Li ◽  
Ming Xu ◽  
...  

Purpose This paper aims to obtain high mechanical and good tribological properties of epoxy resin-based coatings under dry friction conditions. Design/methodology/approach Bonded solid lubricant coatings containing Kevlar fibres were prepared by a spraying method. The friction and wear properties of the coatings were experimentally investigated with a face-to-face tribometre under dry friction conditions. Scanning electron microscopy, energy dispersive X-ray spectroscopy and 3D laser scanning technologies were used to characterise the tribological properties. The action mechanism of the Kevlar fibres on a solid lubricant transfer film was also analysed. Findings Adding Kevlar fibres can significantly improve the wear resistance of the coatings. When the Kevlar fibre content increases, the tribological properties of the coatings improve and then worsen. Superior properties are obtained with 0.03 g of Kevlar fibres. Appropriately increasing the load or speed is beneficial to the removal of the outer epoxy resin and the formation of a lubricant film. During friction, the solid lubricants wrapped in the epoxy resin accumulate on the surface to form a transfer film that shows a good self-lubricating performance. In the later friction stage, fatigue cracks occur on the solid lubricant film but cannot connect to one another because of the high wear resistance and the entanglement of the rod-like Kevlar fibres. Thus, no large-area film falls from the matrix, thereby ensuring the long-term functioning of solid lubricant coatings. Originality/value Epoxy resin-based solid lubricant coatings modified by Kevlar fibres were prepared, and their friction and wear properties were investigated. Their tribological mechanisms were also proposed. This work provided a basis for the analysis of the tribological properties and design of bonded solid lubricant coatings containing Kevlar fibres.


1997 ◽  
Vol 14 (11) ◽  
pp. 865-868 ◽  
Author(s):  
Yang Jian-hua ◽  
Liang Hong ◽  
Zhang Tong-he ◽  
Su Yi ◽  
Zhang Tao

Author(s):  
В.Ю. Фоминский ◽  
В.Н. Неволин ◽  
Д.В. Фоминский ◽  
Р.И. Романов ◽  
М.Д. Грицкевич

The results of a comparative study of the friction and wear of MoSx and MoSex thin film coatings that was carried out in an oxidizing medium (a mixture of argon and air) at a temperature of -100°C are presented. The films were obtained by pulsed laser deposition from MoS2, MoSe2, and Mo targets in vacuum and H2S. It was established that Se-containing coatings significantly exceeded the S-containing coatings in terms of wear resistance and provided a friction coefficient of ~ 0.09. The properties of MoSx films depended on the S concentration, which determines the local packing of atoms in the amorphous structure of the film. The coefficient of friction for MoS3 films after running-in turned out to be half as much as that for MoS2 films, and its value was 0.08.


2013 ◽  
Vol 341-342 ◽  
pp. 92-95
Author(s):  
Li Jun Wang ◽  
Jian Jun Hao ◽  
Yue Jin Ma ◽  
Jian Guo Zhao ◽  
Jian Chang Li

Using plasma spraying equipment to prepare Al2O3-13wt%TiO2 coating on Q235 substrate. Study of its organization and performance, test the performance of coating microhardness and the resistance of friction and wear resistance then optimize the spraying process parameters. The surface of the coating performance was studied by SEM. The results show that, Coating microhardness can be as high as 1132HV, Far more than the matrix microhardness. The minimum average wear weightlessness of Sample surface is 0.95mg. Greatly improve the wear resistance


2018 ◽  
Vol 70 (8) ◽  
pp. 1408-1413 ◽  
Author(s):  
Hongjin Zhao ◽  
Lei Cao ◽  
Yong Wan ◽  
Shuyan Yang ◽  
Jianguo Gao ◽  
...  

Purpose The purpose of this paper is to increase wear resistance of aluminum. Design/methodology/approach The authors have studied the ways to improve the tribological performance of aluminum by assembling stearic acid on aluminum coated by sol-gel-derived TiO2 film. The samples were characterized by infrared spectroscopy, contact angle measurements and a macro friction and wear tester. Findings Enhanced wear resistance was clearly obtained after functionalization of TiO2 film on aluminum by stearic acid. Originality/value The relevant results might be helpful for guiding the surface modification of aluminum devices in industrial applications.


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