Preparation and tribological properties of MoS2/graphite composite coatings modified by La2O3

2018 ◽  
Vol 70 (8) ◽  
pp. 1422-1430
Author(s):  
Ming Qiu ◽  
Rui Zhang ◽  
Yingchun Li ◽  
Hui Du ◽  
Xiao Xu Pang
Keyword(s):  
Service Life ◽  
Abrasive Wear ◽  
Composite Coating ◽  
Tribological Properties ◽  
Wear Mechanisms ◽  
Adhesive Wear ◽  
Composite Coatings ◽  
The Self ◽  
Graphite Composite ◽  
Content Type

PurposeThe MoS2/graphite composite coatings modified by La2O3through spraying technique were successfully prepared on the inner rings of spherical plain bearings. As a comparison, unmodified coatings were also prepared. This paper aims to study the La-modified MoS2/graphite composite coating experimentally and improve the tribological performance of self-lubricating spherical plain bearings.Design/methodology/approachThe performance of La2O3toward the friction coefficient, temperature rise and wear rate of the coatings was studied by a self-made tribo-tester under different swing cycles. And the texture, surface morphology and element composition of the coatings were characterized by scanning electron microscope, energy dispersive spectroscopy and X-ray diffractometry.FindingsThe additives La2O3refined the coatings’ microstructure and improved the tribological properties of the coatings. The oxidation of Mo + 4 to Mo + 6 was effectively inhibited. And the amount of abrasive grains, peeling pits and local cracks on the coatings surface decreased and homogeneous lubricating films formed, which were attributed to the existence of La2O3. The wear mechanisms of unmodified coatings were severe abrasive wear, adhesive wear and delamination wear. However, it exhibited superior wear resistance of the La-modified coatings to unmodified coatings, presenting slight abrasive wear and adhesive wear. The service life of bearings was prolonged under the protection of the modified coatings.Originality/valueThe paper proposed a new modified MoS2/Graphite composite coating for the self-lubricating spherical plain bearings. The investigation on the friction, wear and temperature increase behaviors and the wear mechanisms of the coatings are beneficial to prolonging the service life of the self-lubricating spherical plain bearings.

Electrodeposition and Tribological Properties of Self-Lubricating Sn-Ni-PTFE Composite Coating

2013 ◽  
Vol 572 ◽  
pp. 277-280 ◽  
Author(s):  
Li Xia Ying ◽  
Jun Tao Yang ◽  
Ying Liu ◽  
Zhi Kun Yang ◽  
Gui Xiang Wang
Keyword(s):  
Composite Coating ◽  
Tribological Properties ◽  
Metal Surfaces ◽  
Smooth Surface ◽  
Composite Coatings ◽  
Tribological Performance ◽  
The Self ◽  
Extreme Conditions ◽  
Ptfe Composite ◽  
Fine Microstructure

In order to improve the self-lubricating and anti-wear performances of metal surfaces in the extreme conditions, Sn-Ni-PTFE composite coating was electrodeposited on metal surfaces from the electrolyte containing PTFE emulsion. Microstructure, microhardness and tribological properties of the Sn-NiPTFE composite coatings were investigated. Results show that Sn-Ni-PTFE composite coating has smooth surface and fine microstructure. PTFE particles disperse uniformly in the composite coatings. Simultaneously, the incorporation of PTFE particles significantly improves the tribological performance of Sn-Ni coatings. SnNiPTFE composite coatings exhibits lower friction coefficient and better wear resistance in contrast with Sn-Ni coating.

The tribological properties of bulk Fe2B with pre-oxidation treatment at 750°C in air

2019 ◽  
Vol 72 (1) ◽  
pp. 151-156
Author(s):  
Kemin Li ◽  
Zhifu Huang ◽  
Hanwen Ma ◽  
Shaofei Wang ◽  
Chaofeng Qin ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Abrasive Wear ◽  
Oxide Layer ◽  
Tribological Properties ◽  
Wear Mechanisms ◽  
Design Methodology ◽  
Sample Surface ◽  
Oxidation Treatment ◽  
Soaking Time ◽  
Content Type

Purpose The purpose of this study was to investigate the tribological properties of bulk Fe2B with pre-oxidation treatment. Design/methodology/approach Bulk Fe2B was oxidized in an electric box furnace with a soaking time of 9 min under 750°C in air. Then, the tribological experiments were carried out on an UMT-Tribolab tester. Findings The oxide layer was composed of Fe, Fe2O3, Fe3O4, B2O3 and H3BO3. The oxidative direction of bulk Fe2B was perpendicular to the sample surface. But, the oxidative direction of Fe2B crystals was irregular. At 0.1 m/s, the friction coefficient was the lowest. The effects of shortening the running-in period of friction and reducing the friction coefficient by pre-oxidation treatment at 0.1 m/s were remarkable. Nevertheless, the effect of pre-oxidation treatment was futile at 0.2 m/s. Wear mechanisms of oxidized Fe2B mainly were adhesive and abrasive wear. Originality/value The effects of shortening the running-in period of friction and reducing the friction coefficient by pre-oxidation treatment were remarkable.

scholarly journals Enhanced Mechanical and Tribological Capabilities of a Silicon Aluminum Alloy with an Electroplated Ni–Co–P/Si3N4 Composite Coating

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 120
Author(s):  
Zhijie Li ◽  
Fei Ma ◽  
Dongshan Li ◽  
Shanhong Wan ◽  
Gewen Yi ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
Composite Coating ◽  
Composite Coatings ◽  
Engine Oil ◽  
Si Substrate ◽  
Wear Performance ◽  
Cobalt Layer ◽  
Hard Chrome ◽  
Electroplating Process ◽  
Hardness Values

Ni–Co–P/Si3N4 composite coatings were fabricated over an aluminum–silicon (Al–Si) substrate using a pulse-current electroplating process, in which the rapid deposition of an intermediate nickel–cobalt layer was used to improve coating adhesion. The microstructure, mechanical, and tribological behaviors of the electroplated Ni–Co–P/Si3N4 composite coating were characterized and evaluated. The results revealed that the electroplated Ni–Co–P/Si3N4 composite coating primarily consisted of highly crystalline Ni–Co sosoloid and P, and a volumetric concentration of 7.65% Si3N4. The electroplated Ni–Co–P/Si3N4 composite coating exhibited hardness values almost two times higher than the uncoated Al–Si substrate, which was comparable to hard chrome coatings. Under lubricated and dry sliding conditions, the electroplated Ni–Co–P/Si3N4 composite coating showed excellent anti-wear performance. Whether dry or lubricated with PAO and engine oil, the composite coating showed minimum abrasive wear compared to the severe adhesive wear and abrasive wear observed in the Al–Si substrate.

Abrasive wear mechanisms of fluoropolymer based composite coatings on aluminium substrates

Wear ◽  
1996 ◽  
Vol 200 (1-2) ◽  
pp. 122-136 ◽  
Author(s):  
M.Q. Zhang ◽  
K. Friedrich ◽  
K. Batzar ◽  
P. Thomas
Keyword(s):  
Abrasive Wear ◽  
Wear Mechanisms ◽  
Composite Coatings

Corrosive-wear behavior of LSP/MAO treated magnesium alloys in physiological environment with three pH values

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yongshui Shen ◽  
Tongjin Sun ◽  
Tao Zhu ◽  
Ying Xiong
Keyword(s):  
Abrasive Wear ◽  
Wear Mechanisms ◽  
Adhesive Wear ◽  
Laser Shock ◽  
Corrosion Wear ◽  
Fatigue Wear ◽  
Wear Rates ◽  
Ph Values ◽  
Wear And Corrosion ◽  
Micro Arc Oxidation

Abstract A laser shock peening (LSP) layer, a micro-arc oxidation (MAO) coating, and an LSP/MAO composite coating were fabricated on the surface of AZ80 magnesium alloy by laser shock and micro-arc oxidation process. The ball-disc grinding method was used to perform wear test on the three treated specimens in simulated body fluids (SBF) with pH values of 4, 7.4 and 9. The morphology and element content of worn surface were investigated by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The results indicated that the wear rates of the three treated specimens in three pH environment in numerical order were pH 4 > pH 7.4 > pH 9, respectively. The wear rates of the three treated specimens in the same pH environment were arranged in the order of MAO > LSP > LSP/MAO, respectively. The main wear mechanisms of the LSP specimen in pH 4 environment were fatigue wear and corrosion wear, while it were corrosion wear and adhesive wear in pH 7.4 and pH 9 environments. Abrasive wear, fatigue wear and corrosion wear were the main wear mechanisms of the MAO specimen in pH 4 environment, while abrasive wear, adhesive wear and corrosion wear were the main wear mechanisms of that in pH 7.4 and pH 9 environments. The corrosion wear resistance of the LSP/MAO specimen in SBF solution with three pH values was improved due to the synergism of LSP fine crystal layer and MAO coating.

Effect of Nano Sodium Titanate/ Potassium Titanate Whisker on Tribology Behavior of Brake Materials

2020 ◽  
Vol 993 ◽  
pp. 836-843
Author(s):  
Ke Guo ◽  
Zhi Qiang Zhang ◽  
Zhong Zheng Pei ◽  
Jie Xu ◽  
Yi Fan Feng
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Abrasive Wear ◽  
Wear Mechanisms ◽  
Adhesive Wear ◽  
Sodium Titanate ◽  
Brake Pad ◽  
Potassium Titanate

Here we developed a hot-pressed molded resin-based brake pad material reinforced by a nano sodium titanate whisker in comparison with nano potassium titanate whisker. The effect of the whiskers on the tribology behavior was investigated. Though nano sodium titanate whisker reinforced brake material showed higher porosity (+12.29% averagely) and lower hardness (-25.8% averagely) caused by the impurities, it exhibited improved ability in stabilizing the friction coefficient and enhancing 25.5%, 31.1%, 25.9% higher wear resistance, when the volume contents of whisker are 7.5%, 15% and 22.5%, respectively, compared to the nano potassium titanate whisker reinforced brake material. The wear mechanisms of the nano sodium titanate whisker reinforced brake materials were determined as embedded debris, delaminated crater, moderate layers transfer, uniform furrows, primary plateaus and secondary plateaus in similar size, indicating a main wear form of abrasive wear instead of adhesive wear.

Friction and Wear Behavior of Polypropylene/Montmorillonite Intercalated Nanocomposites

2011 ◽  
Vol 311-313 ◽  
pp. 92-95 ◽  
Author(s):  
Kui Chen ◽  
Tian Yun Zhang ◽  
Wei Wei
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Mechanisms ◽  
Mass Fraction ◽  
Friction And Wear ◽  
Adhesive Wear ◽  
Wear Behavior ◽  
Friction And Wear Behavior

Polypropylene/organo-montmorillonite (PP/OMMT) composites were investigated by XRD. Friction and wear behaviors of this composites sliding against GCr15 stainless steel were examined on M-2000 text rig in a ring-on-block configuration. Worn surfaces of PP and its composites were analyzed by SEM. The result shows that PP macromolecule chains have intercalated into OMMT layers and form intercalated nanocomposites. With the increase of mass fraction of OMMT, both wear rate and friction coefficient of composites first decrease then rise. With the increase of load, from 150 N, 200 N to 250 N, wear rate of composites increases, while friction coefficient reduces. The wear mechanisms of composites are connected with the content of OMMT. Composites were dominated by adhesive wear, abrasive wear and adhesive wear accompanied by abrasive wear respectively with the increase of OMMT content.

Microstructure and corrosion resistance of Ni/Cr3C2-NiCr composite coating

2019 ◽  
Vol 66 (4) ◽  
pp. 471-478 ◽  
Author(s):  
Majid Hosseinzadeh ◽  
Abdol Hamid Jafari ◽  
Rouhollah Mousavi ◽  
Mojtaba Esmailzadeh
Keyword(s):  
Corrosion Resistance ◽  
Composite Coating ◽  
Design Methodology ◽  
Electrochemical Impedance ◽  
Composite Coatings ◽  
Thermal Spraying ◽  
Content Type ◽  
Bath Solution ◽  
Electrochemical Deposition Method ◽  
Base Composite

Purpose In this study, electrochemical deposition method which have cheaper equipment than thermal spraying methods and is available for the production of composite coatings were used. Design/methodology/approach Composite coatings were electrodeposited from a Watts's bath solution in which the suspended Cr3C2-NiCr particles were dispersed in the bath solution during deposition. Potentiodynamic polarization and electrochemical impedance spectroscopy techniques have been used to evaluate the corrosion resistance of the composite coating in the 3.5 Wt.% NaCl solution. Findings It was found that the submicron Cr3C2-NiCr particles distributed uniformly in the coating and depend on the current density of deposition, different amount of particles can be incorporated in the coating. The results showed that the corrosion resistance of the Ni/ Cr3C2-NiCr composite coatings is more comparable to the pure nickel coating. Originality/value Production of Ni-base composite coating from an electrolytic bath containing Cr3C2-NiCr particles is possible via electrodeposition.

High-Speed Dry Tribological Behaviors of CrNiMo Steel in Nitrogen and Oxygen Atmospheres

2011 ◽  
Vol 704-705 ◽  
pp. 877-885
Author(s):  
San Ming Du ◽  
Yong Zhen Zhang ◽  
Bao Shangguan
Keyword(s):  
Abrasive Wear ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Wear Mechanisms ◽  
High Speed ◽  
Normal Load ◽  
Dry Sliding ◽  
Tribological Behaviors ◽  
Electron Dispersion ◽  
Worn Surface

Abstract: In this article, the high-speed dry sliding tribological behaviors of CrNiMo steel against brass in nitrogen and oxygen atmospheres are investigated using a pin-on-disc tribometer. The worn surface is characterized by scanning electron microscopy and electron dispersion spectrums analysis. The wear mechanisms of CrNiMo steel are also analyzed. The results indicate that the tribological properties of CrNiMo steel are coincidental with the law of dry sliding of metal, where the friction coefficients decreases with an increase in sliding speed and with normal load. However, the atmosphere has obvious effects on the tribological properties of CrNiMo steel. In the sliding process, friction heat plays an important role on the tribological properties of materials in high-speed dry friction. The high-speed wear mechanism of CrNiMo steel varies at different atmospheres. In a nitrogen atmosphere, the wear mechanism of CrNiMo steel is mainly characterized by adhesion at a lower speed and load. When the speed and load are increased, melting trace is found in the worn surface accompanied by an abrasive wear. In an oxygen atmosphere, the mechanism is characterized by adhesion at a lower speed and load; with an increase in speed and load, it gradually transformed into oxidation wear and abrasive wear. The difference of the wear mechanisms in the different atmospheres and test parameters is primarily due to the transfer films formed on the contact surfaces of the sliding pairs. In our experimental conditions, the surface film is mainly the metal film in nitrogen, whereas, it is the oxide film in oxygen.

Wear Performance of Rubber Wheel of Roller Guide Shoes

2010 ◽  
Vol 113-116 ◽  
pp. 1930-1934
Author(s):  
Zhen Duo Han ◽  
Chao Qu ◽  
Yu Xing Peng ◽  
Guo An Chen ◽  
Yi Lei Li
Keyword(s):  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Mechanisms ◽  
Adhesive Wear ◽  
Heat Accumulation ◽  
Low Velocity ◽  
Wear Performance ◽  
Roller Guide ◽  
Low Load ◽  
Increasing Load

A wear tester was developed. MC PA (nylon) filled with MoS2 and PU (polyurethane) were used as the material of the rubber wheel of roller guide shoes. Their wear performances was investigated with the tester. The results show that the wear rate of MC PA increases firstly and then decreases with increasing load, and reverses with increasing velocity. The wear rate of PU decreases firstly and then increases with increasing velocity. In addition, the main wear mechanisms of PU are plough wear and abrasive wear at the low load (200N). At the loads of 200N~500N, the main wear form of MC PA is the adhesive wear. Adhesive wear is the main mechanism of MC PA at the low velocity (3m/s). Due to inner heat accumulation by friction, squama-peering occurs on MC PA surface at the high velocity (8m/s). The dominant wear mechanisms of PU are abrasive wear and fatigue pitting. And the main reason of PU’s failure is the interior heat accumulation caused by friction.

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