Investigation of Surface Topography at the End of Running-In Process

2013 ◽  
Vol 437 ◽  
pp. 564-567
Author(s):  
Geng Pei Zhang ◽  
Xiao Jun Liu ◽  
Wen Long Lu ◽  
Xiang Qian Jiang

Running-in process is an important stage of whole wear process. The irrelevance of surface roughness before and after running-in puzzled the running-in research. However, this conclusion was based on surface roughness derived from the 2D surface profile which does not contain 3D information, and was therefore not complete. In this paper, running-in experiments were conducted to investigate the issue. The results showed that there is no equilibrium surface topography similar with equilibrium roughness at the end of running-in process.

Fractals ◽  
2019 ◽  
Vol 27 (08) ◽  
pp. 1950130
Author(s):  
XUE ZUO ◽  
MINGLONG PENG ◽  
YUANKAI ZHOU

The dynamic evolutions of friction force and worn surface profile were qualitatively analyzed by phase trajectory and recurrence plots and quantitatively characterized by fractal dimension and percent determinism. The results show that phase trajectories first shrink to a small volume, then stabilize at a minimum volume, finally expand to a large volume in the wear process. The white areas on the recurrence plots increase with the wear time. The fractal dimension first increases, then stabilizes at a high value, and finally decreases rapidly. The percent determinism first decreases, then fluctuates in a certain range, and finally increases. It demonstrates that friction force and worn surface topography derived from one tribology system evolve in a similar but not exactly the same way. They have the consistent evolution law in the wear process. Specially, friction force is much more sensitive to the variation of wear states than the worn surface.


2010 ◽  
Vol 126-128 ◽  
pp. 658-663 ◽  
Author(s):  
Ze Fei Wei ◽  
Wen Ji Xu ◽  
Gui Bing Pang ◽  
Xu Yue Wang

In this paper, surface topography characteristics of electrochemical mechanical finishing (ECMF) for steel was investigated. The scanning electron microscopy (SEM) was used to observe the surface topography. And the microcosmic geometry parameters were measured by Talysurf SLI2000. Compared with original surface, the surface topography characteristics of the workpiece machined by ECMF have been analyzed with altitude density function (ADF) and auto correlation function (ACF). The results show that there exist periodicity component in surface profile before and after finishing. The auto correlation curves of ECMF surface have a smaller average period compared with grinding surface. The low-frequency component and the mean ripple peak distance of original surface profile are obviously decreased. Furthermore, the ripples and peak density are increased, and the surface roughness Ra is decreased from 0.231μm to 0.023μm. The results indicate that surface quality, material ratio of the profile and wear resistance machined by ECMF are improved obviously.


2010 ◽  
Vol 44-47 ◽  
pp. 4077-4080
Author(s):  
Mei Fa Huang ◽  
Xiong Cheng ◽  
Bing Kuang ◽  
Jiang Tai Huang

The quality of workpiece is influenced by the surface roughness. However, the assessment of parameters of surface roughness is not researched intensively in the new generation GPS standards system. This paper presents a method to assess parameters of surface roughness. The methodology adopts wavelet analysis to construct the model of surface topography and uses the mallat algorithm to separate roughness profile from surface topography. The assessment results of surface profile are calculated according to the standard ISO 4287:1997. The experimental results show that the method not only avoids simplicity the assessment of parameters, but also decreases the number of productions of mis-acceptance and mis-rejection.


2014 ◽  
Vol 707 ◽  
pp. 90-93
Author(s):  
Li Li ◽  
Wei Li ◽  
Tao Li

A series of samples which have different surface roughness made by 45 steel were treated by Ultrasonic Deep Rolling (UDR), influence of original surface roughness on UDR effects, such as surface profile, surface roughness and residual stress, were studied. Results shows that surface roughness was reduced substantially through UDR treating and lager the original surface roughness, larger surface roughness and surface residual stress induced by UDR treating.


2021 ◽  
Vol 10 (4) ◽  
pp. e51610414425
Author(s):  
Ana Virgínia Lot ◽  
Ana Paula Margarido Menegazzo ◽  
Camila Tavares Brasileiro ◽  
Fábio Gomes Melchiades ◽  
Anselmo Ortega Boschi

The increase of surface roughness is a common measure for improving the slip resistance of floors. Nevertheless, the surface roughness of the floors can wear out during the use. Furthermore, rough surfaces can be susceptible to dirt accumulation. As a consequence, during the use, the original slip resistance and visual appearance of the floors can be deteriorated. In this scenario, the objective of this work was to evaluate the effects of pedestrian traffic on the surface profile, slip resistance and visual appearance of commercial ceramic floor tiles. The surface profile (contact profilometer), slip resistance (pendulum method) and visual appearance (visual analysis) of different commercial ceramic floors were evaluated before and after their exposure to heavy pedestrian traffic, and the results were compared. Significant reductions of the sharpness and height of profile peaks of the surfaces, due to mechanical wear, were observed. Consequently, for all the surfaces which initially presented satisfactory slip resistance for use in slipping risk areas, this property was reduced to unsafe levels. The degree of dirt accumulation, and the consequent visual appearance deterioration, varied according to the profile characteristics of the studied floors. The best cleaning performances were found for surfaces with more spaced irregularities and wider profile valleys.


Author(s):  
I. Barányi ◽  
G. Kalácska ◽  
Patrick De Baets

Surface microtopography plays a dual role in the course of friction and wear processes. It affects the contact and temperature conditions, and it undergoes significant changes in accordance with the wear mechanism. The amplitude, spacing, hybrid and functional parameters of microtopographies provide opportunities for understanding more deeply the wear process. Wear experiments and surface roughness measurements before and after the wear were performed. The aim of this study was to define the availability of the roughness parameters to describe the microtopography modification during the abrasive tribological process.


Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.


Nanoscale ◽  
2020 ◽  
Author(s):  
Feifei ZHANG ◽  
Jérôme Plain ◽  
Davy Gerard ◽  
Jérôme Martin

The surface topography is known to play an important role on the near- and far- field optical properties of metallic nanoparticles. In particular, aluminum (Al) nanoparticles are commonly fabricated through...


2021 ◽  
Vol 9 (1) ◽  
pp. 8
Author(s):  
Murtadha AlAli ◽  
Nikolaos Silikas ◽  
Julian Satterthwaite

Objective: To evaluate and compare the surface roughness and gloss of a DMA-free composite and Bis-GMA-free composite with a DMA-based composite before and after toothbrushing simulation. Materials and Methods: Fifteen dimensionally standardised composite specimens of three nano-hybrid resin composites (Tetric EvoCeram, Admira Fusion, and Venus Diamond) were used. Five specimens from each composite were polished and then subjected to a toothbrushing simulator. Surface roughness (Ra) and gloss were measured before toothbrushing and after 5000, 10,000, 15,000, and 20,000 toothbrushing cycles. The data was analysed using 5 × 3 ANOVA to assess surface roughness and gloss values and pairwise comparisons in the form of Tukey post hoc tests were performed to interpret main effects. Results: For all tested materials, surface roughness increased, and gloss decreased after toothbrushing abrasion. Surface roughness (Ra) values ranged from 0.14 to 0.22 μm at baseline and increased to between 0.41 and 0.49 μm after 20,000 toothbrushing cycles. Gloss values ranged between 31.9 and 50.6 GU at baseline and between 5.1 and 19.5 GU after 20,000 toothbrushing cycles. The lowest initial Ra value was detected in Venus Diamond and the highest initial gloss value was detected in Tetric EvoCeram. Conclusions: Simulated toothbrushing abrasion led to an increase in surface roughness and a decrease in gloss for all tested materials. Venus Diamond had the smoothest surface and Tetric EvoCeram had the glossiest surface after polishing and following 20,000 cycles of toothbrushing abrasion. Admira Fusion demonstrated the roughest surface and had the lowest gloss values before and after toothbrushing abrasion.


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