scholarly journals Polydopamine-Assisted Immobilization of Chitosan Brushes on a Textured CoCrMo Alloy to Improve its Tribology and Biocompatibility

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3014 ◽  
Author(s):  
Liguo Qin ◽  
Hongjiang Sun ◽  
Mahshid Hafezi ◽  
Yali Zhang

Due to their bioinert and reliable tribological performance, cobalt chromium molybdenum (CoCrMo) alloys have been widely used for articular joint implant applications. However, friction and wear issues are still the main reasons for the failure of implants. As a result, the improvement of the tribological properties and biocompatibility of these alloys is still needed. Thus, surface modification is of great interest for implant manufacturers and for clinical applications. In this study, a strategy combining laser surface texturing and chitosan grafting (mussel inspired) was used to improve the tribological and biocompatible behaviors of CoCrMo. The microstructure and chemical composition were investigated by atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy, respectively. The tribological properties were discussed to determine their synergistic effects. To evaluate their biocompatibility, osteoblast cells were cocultured with the modified surface. The results show that there is a distinct synergistic effect between laser surface texturing and polymer brushes for improving tribological behaviors and biocompatibility. The prepared chitosan brushes on a textured surface are a strong mechanism for reducing friction force. The dimples took part in the hydrodynamic lubrication and acted as the container for replenishing the consumed lubricants. These brushes also promote the formation of a local lubricating film. The wear resistance of the chitosan brushes was immensely improved. Further, the worn process was observed, and the mechanism of destruction was demonstrated. Co-culturing with osteoblast cells showed that the texture and grafting have potential applications in enhancing the differentiation and orientation of osteoblast cells.

2016 ◽  
Vol 68 (1) ◽  
pp. 116-124 ◽  
Author(s):  
Dawit Zenebe Segu ◽  
Pyung Hwang

Purpose – The purpose of this paper is to investigate and discuss the effect of multi-shape laser surface texturing (LST) steel surfaces on tribological performance. Design/methodology/approach – The textured surface with some specific formula arrays was fabricated by laser ablation process by combining patterns of circles and triangles, circles and squares and circles and ellipses. The tribological test was performed by a flat-on-flat tribometer under dry and lubrication conditions, and results were compared with that of untextured surface. Findings – The results showed that the textured surface had better friction coefficient performance than the untextured surface due to hydrodynamic lubrication effect. Through an increase in sliding speed, the beneficial effect of LST performance was achieved under dry and lubrication conditions. Originality/value – This paper develops multi-shape LST steel surfaces for improving the friction and wear performance under dry and lubrication conditions.


Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 981 ◽  
Author(s):  
Ming-xue Shen ◽  
Zhao-xiang Zhang ◽  
Jin-tao Yang ◽  
Guang-yao Xiong

Polymer brush layers can act as effective lubricants owing to their low friction and good controllability. However, their application to the field of tribology is limited by their poor wear resistance. This study proposes a strategy combining grafting and surface texturing to extend the service life of polymer brushes. Surface microstructure and chemical composition were measured through scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Water contact angles were measured to evaluate the surface wettability of the grafted silicon-based surface texture. Results showed the distinct synergistic effect between polymer brushes and laser surface texturing (LST). The prepared polymer brushes on textured surface can be a powerful mechanism for friction reduction properties, which benefit from their strong hydration effect on the lubrication liquid and promote the formation of a local lubricating film. Moreover, the wear life of polymer brushes can be immensely extended, as micro-dimples on the textured surface can effectively protect the polymer brushes. This study presents a method to enhance the load-bearing capacity and wear resistance of the grafted surface of polymer brushes.


Friction ◽  
2021 ◽  
Author(s):  
Chia-Jui Hsu ◽  
Andreas Stratmann ◽  
Simon Medina ◽  
Georg Jacobs ◽  
Frank Mücklich ◽  
...  

AbstractLaser surface texturing (LST) has been proven to improve the tribological performance of machine elements. The micro-scale patterns manufactured by LST may act as lubricant reservoirs, thus supplying oil when encountering insufficient lubrication. However, not many studies have investigated the use of LST in the boundary lubrication regime, likely due to concerns of higher contact stresses that can occur with the increasing surface roughness. This study aims to examine the influence of LST on the fatigue lifetime of thrust rolling bearings under boundary lubrication. A series of periodic patterns were produced on the thrust rolling bearings, using two geometrically different designs, namely cross and dimple patterns. Base oil ISO VG 100 mixed with 0.05 wt% P of zinc dialkyldithiophosphate (ZDDP) was supplied. The bearings with cross patterns reduce the wear loss by two orders of magnitude. The patterns not only retain lubricant in the textured pockets but also enhance the formation of an anti-wear tribofilm. The tribofilm generation may be improved by the higher contact stresses that occur when using the textured surface. Therefore, in contrast to the negative concerns, the ball bearings with cross patterns were instead found to increase the fatigue life by a factor of three.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Junru Wang ◽  
Quandai Wang ◽  
Yueyan Li ◽  
Meiling Guo ◽  
Pengyang Li ◽  
...  

Purpose The purpose of this paper is to investigate the effects of surface texture with roughness orientation considered on tribological properties under a mixed lubrication state numerically and experimentally. Design/methodology/approach Based on the average Reynolds equation and asperity contact model, the impacts of surface texture parameters and roughness orientation on lubrication properties have been calculated using finite difference method. Tin–bronze samples with various prescribed surface texture geometric parameters and roughness orientation were fabricated by laser surface texturing technique, and the tribology performance of the textured surface was studied experimentally. Findings The effects of surface geometric parameters and roughness orientation parameters have been discerned. The experimental observations are in good agreement with the numerical prediction, which suggests that the numerical scheme adopted in this work is suitable in capturing the surface texture and roughness effect under mixed lubrication state. Originality/value By meticulously controlling the surface roughness and surface texture geometric characteristics based on the laser surface texturing process, samples with prescribed surface texture parameters and roughness orientation consistent with that in theoretical studies were fabricated and the theoretical model and results were verified experimentally.


2017 ◽  
Vol 329 ◽  
pp. 29-41 ◽  
Author(s):  
Johnny Dufils ◽  
Frédéric Faverjon ◽  
Christophe Héau ◽  
Christophe Donnet ◽  
Stéphane Benayoun ◽  
...  

2020 ◽  
Vol 42 (1) ◽  
pp. 159-164
Author(s):  
D. Maldonado-Cortés ◽  
L. Peña-Parás ◽  
C. Leyva Leyva ◽  
A. Guerrero ◽  
A. Garza ◽  
...  

2021 ◽  
Author(s):  
Vishal Uttamra Bagade ◽  
Muthukannan Duraiselvam ◽  
Niranjan Sarangi ◽  
Parthiban K

Abstract In aero gas turbine engine, copper nickel indium (CuNiIn) and molybdenum loaded disulphide (MoS2) duplex coating is applied on Ti6Al4V blades in bladed disk configuration of low pressure and high pressure compressor. Coating between blade and disk is provided to prevent fretting wear due to direct metal to metal contact of Ti6Al4V. Generally, grit blasting will be done for preparation of the surface before the application of coating. Laser surface texturing (LST) process can be explored by aero engine industry as a new surface preparation process for compressor blades. To compare two different surface preparation methods, Ti6Al4V surface is prepared by two different processes, conventional grit blasting as well as laser surface texturing (LST). LST with different elliptical and square patterns are created on Ti6Al4V. Surface topography is analyzed by SEM and WLI. CuNiIn is sprayed by atmospheric plasma spray (APS) and MoS2 on top of CuNiIn by painting and curing. Effects of surface preparation on coating adherence as well as on tribological properties are studied. The results showed that geometry and dimensions of LST pattern influences the coating adherence and wear performance. LST process can be optimized for better performance and explored as an alternative surface preparation process in industry for thermal spray coatings.


Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 990 ◽  
Author(s):  
Lin Cao ◽  
Yun Chen ◽  
Jie Cui ◽  
Wei Li ◽  
Zhidan Lin ◽  
...  

The poor tribological performances of titanium have significantly limited its applications in the field of artificial joints. In order to solve problems regarding the wear and corrosion of artificial joints in the body, we fabricated the composite materials utilizing the combination of laser surface texturing and nitrogen ion implantation technology, and investigated the effect of laser surface texturing, nitrogen ion implantation, and different dimple area densities on tribological performance. The results show that the textured surface could reduce the friction coefficient and improve the wear resistance, and the optimum dimple density was found to be 25%. After N ion implantation, the wear resistance of the textured sample was further improved, due to the formation of the nitride layer. Moreover, as shown by the electrochemical test results, the corrosion resistance was enhanced significantly. The friction coefficient decreased the most, and the wear resistance increased by 405% with the lowest wear rate of 0.37 × 10−3 mm3/N·m. However, the specimen with a dimple density of 60% had the worst wear resistance. The results of the study provide a basis for the development and application of artificial joint materials.


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