INFLUENCE OF SURFACE POLISHING ON THE FRICTION BEHAVIORS OF NBR

2018 ◽  
Vol 25 (07) ◽  
pp. 1950016 ◽  
Author(s):  
BINGQI JIANG ◽  
XIAOHONG JIA ◽  
FEI GUO ◽  
YUMING WANG
Keyword(s):  
Molecular Structure ◽  
Experimental Study ◽  
Contact Angle ◽  
Friction Coefficient ◽  
Surface Topography ◽  
Friction Process ◽  
Surface Polishing ◽  
Shearing Strength ◽  
Mechanical Breaking ◽  
Abrasive Paper

An experimental study on the tribology behavior and mechanism of NBR-Steel pair has been carried out. Abrasive paper was used to polish the NBR surface. The influences of surface topography on the friction coefficient were investigated based on the block-on-ring tribometer. Results show that polishing with abrasive paper is an effective method to reduce the friction coefficient of NBR on steel. Superlubricity was also found in the test. A new method to explain the superlubricity based on the contact angle and surface molecular structure was put forward in this work. Abrasive paper polishing changes the surface asperities, so affects the contact angle, so as to influence the boundary limiting shearing strength, and then causes the superlubricity. During the friction process the microstructure obviously changed, along with mechanical breaking of the molecular chain.

scholarly journals Experimental study of the contact line friction coefficient

2020 ◽  
Vol 1677 ◽  
pp. 012156
Author(s):  
N Sibiryakov ◽  
W Zheng ◽  
O Kabov ◽  
B Bai
Keyword(s):  
Experimental Study ◽  
Friction Coefficient ◽  
Contact Line ◽  
Contact Line Friction

Processing and Mechanical Properties of Ultra-high Molecular Weight Polyethylene Reinforced by Silver Nanoparticles

2017 ◽  
Vol 25 (9) ◽  
pp. 683-688 ◽  
Author(s):  
Xueqin Kang ◽  
Chi Yao ◽  
Lei Qiao ◽  
Gaofeng Ge ◽  
Peizhong Feng
Keyword(s):  
Molecular Weight ◽  
Contact Angle ◽  
Silver Nanoparticles ◽  
Friction Coefficient ◽  
Creep Resistance ◽  
Mass Fraction ◽  
Friction And Wear ◽  
Indentation Hardness ◽  
Ball Indentation ◽  
Ultra High Molecular Weight

The present study was designed to investigate the mechanical performance of ultra high molecular weight polyethylene (UHMWPE) reinforced by silver nanoparticles. The Ag/UHMWPE nanocomposites were prepared by a plate vulcanizing machine and tested with a contact angle micrometer, UMT friction tester, electronic universal testing machine and MicroXAM three-dimensional profilometer to characterise the wettability, ball indentation hardness, creep resistance, compression properties, and friction and wear performance. A scanning electron microscope (SEM) was employed to describe the morphology of the Ag/UHMWPE nanocomposites surfaces following the friction and wear tests. These results demonstrate that the compressive yield strength, ball indentation hardness and creep resistance increased with an increase in the content of silver nanoparticles. The contact angle of the Ag/UHMWPE nanocomposites with bovine calf serum decreases with an increase in the content of silver nanoparticles and this change increases the wettability of the Ag/UHMWPE nanocomposites. Therefore, the friction coefficient decreases, but the wear mechanism changes from scratch and furrow to fatigue flakes when the mass fraction of silver nanoparticles exceeds 0.3%. The composite with a silver nanoparticles mass fraction of 0.3% exhibits a low friction coefficient and good wear resistance.

Analysis of multi-stage running-in process of Sn-11Sb-6Cu alloy and AISI 1045 with phase trajectory plot

2021 ◽  
pp. 1-14
Author(s):  
Yuankai Zhou ◽  
Huan Zhao ◽  
Xue Zuo
Keyword(s):  
Diesel Engine ◽  
Friction Coefficient ◽  
Surface Topography ◽  
Phase Trajectory ◽  
Sliding Bearings ◽  
Phase Trajectories ◽  
Multi Stage ◽  
Stable Attractor ◽  
Aisi 1045

Abstract Running-in of the main bearings of diesel engine is a crucial process before service. Multi-stage running-in is a better way to enhance running-in quality and efficiency. In order to reveal the evolution of phase trajectory and compare the running-in quality, the running-in tests were performed with the material of bearing bush (Sn-11Sb-6Cu) and shaft (AISI 1045). The running-in quality was comprehensively evaluated via friction coefficient, phase trajectory and surface topography. Results indicate that the phase trajectories show a trend of stage-by-stage convergence. The multi-stage running-in can achieve a more stable attractor, lower friction coefficient and smoother surface, that is, a better running-in quality than the constant running-in scheme. This study provides a reference for formulating running-in specifications for sliding bearings.

Experimental Study of a Variable Pressure Damper on Automotive Valve Motion

1996 ◽  
Author(s):  
Jin-Jang Liou ◽  
Grodrue Huang ◽  
Wensyang Hsu
Keyword(s):  
Experimental Study ◽  
Friction Coefficient ◽  
Friction Force ◽  
High Speed ◽  
Experimental Results ◽  
Variable Pressure ◽  
Friction Forces ◽  
Valve Spring ◽  
Valve Motion

Abstract A variable pressure damper (VPD) is used here to adjusted the friction force on the valve spring to investigate the relation between the friction force and the valve bouncing phenomenon. The friction force on the valve spring is found experimentally, and the corresponding friction coefficient is also determined. Dynamic valve displacements at different speeds with different friction forces are calibrated. Bouncing and floating of the valve are observed when the camshaft reaches high speed. From the measured valve displacement, the VPD is shown to have significant improvement in reducing valve bouncing distance and eliminating floating. However, experimental results indicate that the valve bouncing can not be eliminated completely when the camshaft speed is at 2985 rpm.

scholarly journals Development of hot surfaces generated by friction contacts of titanium alloy and steel

2020 ◽  
Vol 12 (9) ◽  
pp. 168781402095779
Author(s):  
He Pan ◽  
Yang Zhang
Keyword(s):  
Titanium Alloy ◽  
Friction Coefficient ◽  
Surface Temperature ◽  
Coal Mine ◽  
Ignition Source ◽  
Low Friction ◽  
Friction Process ◽  
Tc4 Titanium Alloy ◽  
Element Simulation ◽  
Hot Surface

When light alloys used in coal mine, the sparks generated by mechanical friction and impacts are the main effective ignition source. While the hot surfaces are concomitant in friction process, prior to the occurrence of mechanical sparks, whether the hot surfaces will be an effective ignition source. Then this paper focuses on the development of hot surfaces generated by TC4 titanium alloy at the low friction velocities. Experiments and finite element simulation methods were used together to describe the temperature field of TC4 titanium alloy. It was found that the temperature of hot surfaces increased with the load and increased much faster at higher relative speed. By means of regression analysis, the variation law of friction coefficient and contact pressure with loads and the variation law of hot surface temperature with friction coefficient and pressure were studied, then the fitting curve of hot surface temperature was obtained. The results of calculations and experiments indicate that hot surfaces generated by light alloy was possible to be an effective ignition source for methane air mixture in coal mine.

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