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.

A study on the wear behavior of tin-based journal bearing under different working conditions

2019 ◽  
Vol 72 (3) ◽  
pp. 359-368
Author(s):  
Hulin Li ◽  
Zhongwei Yin ◽  
Yanzhen Wang
Keyword(s):  
Friction Coefficient ◽  
Abrasive Wear ◽  
Working Conditions ◽  
Wear Mechanisms ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Wear Loss ◽  
Fatigue Wear ◽  
Content Type

Purpose The purpose of this paper is to study the friction and wear properties of journal bearings under different working conditions. Design/methodology/approach Friction coefficient and wear losses of journal bearing under different working conditions have been determined by a bearing test rig. The worn surfaces of bearing were examined by scanning electron microscopy and laser three-dimensional micro-imaging profile measurements, and the tribological behavior and wear mechanisms were investigated. Findings The wear loss and friction coefficient of bearing under starting-stopping working condition is far greater than that of steady-state working conditions. In addition, the maximum wear loss under start-up and stop conditions is about 120 times of that under stable operating conditions. Under stable working conditions, the main wear forms of bearings are abrasive wear, under starting-stopping working conditions the main wear mechanisms of bearings are adhesion wear, abrasive wear and fatigue wear. Originality/value These research results have certain practical value for understanding the tribology behavior of journal bearings under different working conditions.

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.

Tribological and electrical behavior of Cu-based composites with addition of Ti-doped NbSe2 nanoplatelets

2018 ◽  
Vol 70 (3) ◽  
pp. 560-567 ◽  
Author(s):  
Jian Feng Li ◽  
Qin Shi ◽  
HeJun Zhu ◽  
ChenYu Huang ◽  
Shuai Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Friction Coefficient ◽  
Electrical Properties ◽  
Tribological Properties ◽  
Solid State Reaction ◽  
Electrical Contact ◽  
Solid State Reaction Method ◽  
Content Type ◽  
Reaction Method

Purpose This paper aims to clarify the size and morphology of transition metal dichalcogenides has an impact on lubrication performance of Cu-based composites. This study is intended to show that Cu-based electrical contact materials containing Nb0.91Ti0.09Se2 have better electrical and tribological properties than those containing NbSe2. The tribological properties of Cu-based with different Ti-dopped NbSe2 content were also discussed. Design/methodology/approach The NbSe2 and Nb0.91Ti0.09Se2 particles were fabricated by thermal solid state reaction method. The powder metallurgy technique was used to fabricate composites with varying Nb0.91Ti0.09Se2 mass fraction. The phase composition of Cu-based composites was identified by X-ray diffraction, and the morphology of NbSe2/Nb0.91Ti0.09Se2 and the worn surface of composites were characterized by scanning electron microscopy and transmission electron microscopy. In addition, the tribological properties of composites were appraised using a ball-on-disk multi-functional tribometer. The data of friction coefficient and resistivity were analyzed and the corresponding conclusion was drawn. Findings In comparison with the pure copper, Cu-based composites containing Nb0.91Ti0.09Se2/NbSe2 had a lower friction coefficient, illustrating the Nb0.91Ti0.09Se2 with nano-size particles prepared in this work is a perfect choice for the fabrication of excellent electrical contact composites. Compared to composites with NbSe2, composites containing Nb0.91Ti0.09Se2 have better tribological and electrical properties. Research limitations/implications Because of the use of thermal solid state reaction method, the size of NbSe2 and Nb0.91Ti0.09Se2 is relatively large. Therefore, the fabrication of finer particles of Nb0.91Ti0.09Se2 is encouraged. Originality/value In this paper, the authors discuss the tribological and electrical properties of Cu-based composites, and the value of optimum obtained as Nb0.91Ti0.09Se2 content is 15 Wt.%.

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.

Effect of non-Newtonian magneto-elastohydrodynamic on performance characteristics of slider-bearings

2019 ◽  
Vol 71 (10) ◽  
pp. 1158-1165
Author(s):  
Mouhcine Mouda ◽  
Mohamed Nabhani ◽  
Mohamed El Khlifi
Keyword(s):  
Friction Coefficient ◽  
Design Methodology ◽  
Reynolds Equation ◽  
Load Capacity ◽  
Transverse Magnetic ◽  
Finite Width ◽  
Two Dimensional ◽  
Content Type ◽  
Slider Bearings ◽  
First Time

Purpose This study aims to examine the magneto-elastohydrodynamic effect on finite-width slider-bearings lubrication using a non-Newtonian lubricant. Design/methodology/approach Based on the magneto-hydrodynamic (MHD) theory and Stokes micro-continuum mechanics, the modified two-dimensional Reynolds equation including bearing deformation was derived. Findings It is found that the bearing deformation diminishes the load-capacity and increases the friction coefficient in comparison with the rigid case. However, the non-Newtonian effect increases load-capacity but decreases the friction coefficient. Moreover, the use of a transverse magnetic field increases both the friction coefficient and load capacity. Originality/value This study combines for the first time MHD and elastic deformation effects on finite-width slider-bearings using a non-Newtonian lubricant.

The tribological performance of engineered micro-surface topography by picosecond laser on PEEK

2019 ◽  
Vol 72 (1) ◽  
pp. 172-179 ◽  
Author(s):  
Meiling Wang
Keyword(s):  
Tribological Properties ◽  
Design Methodology ◽  
Friction And Wear ◽  
Picosecond Laser ◽  
Wear Property ◽  
Content Type ◽  
Friction Curve ◽  
Micro Structures ◽  
Wear Tests ◽  
Friction And Wear Tests

Purpose The purpose of this study is to investigate the effect of engineered micro-structures on the tribological properties of metal-polyetheretherketone (PEEK) surface. Design/methodology/approach Circular dimples with diameters of 25 and 50 µm were designed and manufactured on PEEK plate specimens using picosecond laser. Reciprocating friction and wear tests on a ball-on-flat configuration were performed to evaluate the tribological properties of the designed micro-structures in dry contacts. The loading forces of 0.9 and 3 N were applied. Findings As a result, obvious fluctuations of coefficient of friction curve were observed in tribosystems consisting of non-textured and textured PEEK with circular dimples of 25 µm in diameter. GCr15 ball/textured PEEK plate specimens with circular dimples of 50 µm in diameter revealed a superior friction and wear property. Originality/value Different to the existing studies in which the tribopairs consist of hard bearing couples, this study investigated the tribological properties of the engineered micro-structures on the hard-on-soft bearing couples.

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.

Effects of Environmental Humidity on the Tribological Properties of Modified PTFE Three-Layer Composites

2013 ◽  
Vol 631-632 ◽  
pp. 463-466
Author(s):  
Ting Xie ◽  
Ting Ting Yang ◽  
Wen Juan Yang ◽  
Ming Tian
Keyword(s):  
Friction Coefficient ◽  
Tribological Properties ◽  
Wear Mechanisms ◽  
Test Results ◽  
Friction Coefficients ◽  
Environmental Humidity

In this paper, the tribological properties of the modified PTFE three-layer composites in different humidities were studied. The wear mechanisms of the modified PTFE three-layer composites with and without PI were also analyzed. The test results showed that in the humidity of 15%-75%, the friction coefficients of the composites increased with the humidity increased. At the humidity of 100%, the friction coefficient reduced significantly. With the increase of humidity, the wear of the composites decreased at first and then increased. The smallest wear appeared when the humidity was 45% or 60% for with or without PI composites respectively. And the results also revealed that PI is helpful to improve the wear stability of the composites in different humidities.

Experimental, numerical and analytical studies of abrasive wear: correlation between wear mechanisms and friction coefficient

2005 ◽  
Vol 333 (11) ◽  
pp. 830-837 ◽  
Author(s):  
Salah Mezlini ◽  
M. Zidi ◽  
H. Arfa ◽  
Mohamed Ben Tkaya ◽  
Philippe Kapsa
Keyword(s):  
Friction Coefficient ◽  
Abrasive Wear ◽  
Wear Mechanisms ◽  
Analytical Studies

Optimization of pre-oxidation time for corrosion resistance of cobalt based coating alloy in mixed sulphates

2021 ◽  
Vol 68 (1) ◽  
pp. 29-35
Author(s):  
Abdul Rehman ◽  
Mohammad Hassan Shirani Bidabadi ◽  
Liang Yang ◽  
Zheng Yu ◽  
Chen Hao ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Hot Corrosion ◽  
Design Methodology ◽  
Corrosion Behaviour ◽  
Ambient Air ◽  
Oxidation Time ◽  
Oxidation Treatment ◽  
Content Type ◽  
Surface Oxides ◽  
Oxidation Effect

Purpose This study aims to optimise the effect of pre-oxidation on hot corrosion behaviour of Tribaloy T-900 at 900 °C in mixed Na2SO4 and K2SO4. Design/methodology/approach Prior to hot corrosion experiment, pre-oxidation treatments were carried in ambient air at 900 °C for 1, 5 and 10 h, respectively. The hot corrosion experiments were performed in a box type furnace at 900 °C. Both surfaces of specimens were brushed with saturated salt solution of 75 wt.% Na2SO4 + 25 wt.% K2SO4. After brushing, the salt-coated specimens were placed in electric stove to ensure drying of salt. After drying, presence of 3 mg/cm2 salt on specimen’s surface was ensured through weighting. Findings The 1-h pre-oxidation treatment prior to hot corrosion showed superior hot corrosion resistance against molten salt attack. An optimum pre-oxidation time of 1 h helped timely formation of protective Cr2O3 layer and inhibited the formation of less stable and porous surface oxides of Ni and Mo during hot corrosion. Originality/value Pre-oxidation effect on hot corrosion behaviour of refractory metal (such as Mo in investigated alloy) containing alloy has never been reported previously. Refractory metals oxide (e.g. MoO3) could transform the corrosion phenomena to catastrophic failure through acidic fluxing.

Sign in / Sign up

Export Citation Format

Share Document