Characterisation of abrasive worn surfaces by surface microtopography parameters

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
I. Barányi ◽  
G. Kalácska ◽  
Patrick De Baets
Keyword(s):  
Surface Roughness ◽  
Wear Mechanism ◽  
Friction And Wear ◽  
Dual Role ◽  
Roughness Parameters ◽  
Wear Process ◽  
Functional Parameters ◽  
Surface Microtopography ◽  
Before And After ◽  
Roughness Measurements

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.

Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

1996 ◽  
Vol 54 ◽  
pp. 866-867
Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould
Keyword(s):  
Surface Roughness ◽  
Zeolite Y ◽  
Atomic Level ◽  
Microporous Structure ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Roughness Measurements ◽  
Cracking Catalysts

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.

scholarly journals Sensitivity of C-Band SAR Polarimetric Variables to the Directionality of Surface Roughness Parameters

2021 ◽  
Vol 13 (11) ◽  
pp. 2210
Author(s):  
Zohreh Alijani ◽  
John Lindsay ◽  
Melanie Chabot ◽  
Tracy Rowlandson ◽  
Aaron Berg
Keyword(s):  
Surface Roughness ◽  
Soil Moisture ◽  
Laser Scanner ◽  
Careful Attention ◽  
Roughness Parameters ◽  
Retrieval Models ◽  
Surface Roughness Parameters ◽  
The Look ◽  
The Relationship ◽  
Roughness Measurements

Surface roughness is an important factor in many soil moisture retrieval models. Therefore, any mischaracterization of surface roughness parameters (root mean square height, RMSH, and correlation length, ʅ) may result in unreliable predictions and soil moisture estimations. In many environments, but particularly in agricultural settings, surface roughness parameters may show different behaviours with respect to the orientation or azimuth. Consequently, the relationship between SAR polarimetric variables and surface roughness parameters may vary depending on measurement orientation. Generally, roughness obtained for many SAR-based studies is estimated using pin profilers that may, or may not, be collected with careful attention to orientation to the satellite look angle. In this study, we characterized surface roughness parameters in multi-azimuth mode using a terrestrial laser scanner (TLS). We characterized the surface roughness parameters in different orientations and then examined the sensitivity between polarimetric variables and surface roughness parameters; further, we compared these results to roughness profiles obtained using traditional pin profilers. The results showed that the polarimetric variables were more sensitive to the surface roughness parameters at higher incidence angles (θ). Moreover, when surface roughness measurements were conducted at the look angle of RADARSAT-2, more significant correlations were observed between polarimetric variables and surface roughness parameters. Our results also indicated that TLS can represent more reliable results than pin profiler in the measurement of the surface roughness parameters.

scholarly journals Preliminary In Vitro Wear Assessment of Ceramic Cemented Femoral Components Coupled with Polyethylene Menisci

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2112
Author(s):  
Saverio Affatato ◽  
Paolo Erani ◽  
Maurizio Fersini ◽  
Vincenzo Contaldi ◽  
Anna Rita Terrizzi ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Monoclinic Phase ◽  
Calf Serum ◽  
Wear Test ◽  
Clinical Test ◽  
Preliminary Evaluation ◽  
Before And After ◽  
Roughness Measurements

Success of total knee replacement (TKR) depends on the prosthetic design and materials. The use of metal components is well established with the disadvantage of allergic reactions. Ceramics have been recently proposed because of high wear resistance, excellent biocompatibility, wettability, and suitable mechanical properties. This study was aimed at investigating in vitro wear resistance of Zirconia Toughened Alumina (ZTA)/Ultra-high-molecular-weight polyethylene (UHMWPE) of TKR femoral components. An in vitro protocol was designed with the application of relevant load profile, 6-degrees-of-freedom knee simulator, and 8 × 105 cycles on the ZTA/UHMWPE configuration under bovine calf serum. Before and after wear test, the femoral components were investigated by using the Scanning Electron Microscope (SEM) and the X-Ray Diffraction (XRD) analyses, and stylus surface roughness measurements. The proposed pre-clinical test yielded repeatable results. In particular, gravimetric results showed that, after 8 × 105 cycles, the mean weight loss of the polyethylene mobile components is 5.3 ± 1.1 mg. The surface roughness measurements (Ramax) performed after the wear test showed no significant variation on the UHMWPE menisci. A slight increase of roughness has been found on the ZTA (0.02 µm before wear test, 0.28 µm after the test). SEM observations did not show significant modification of the surface morphology. Tetragonal to monoclinic phase ratio was measured by XRD before and after wear test to evaluate stability of tetragonal ZrO2 phase. Minimal conversion of tetragonal to monoclinic phase was found from 5.4 to 8%. Although this study is a preliminary evaluation limited to in vitro tests, it provides novel pre-clinical indications about the potential of ceramic TKR femoral components.

scholarly journals Enamel Surface Roughness after Lingual Bracket Debonding: An In Vitro Study

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4196
Author(s):  
Martina Eichenberger ◽  
Anna Iliadi ◽  
Despina Koletsi ◽  
George Eliades ◽  
Carlalberta Verna ◽  
...  
Keyword(s):  
Surface Roughness ◽  
In Vitro Study ◽  
Rank Test ◽  
Roughness Parameters ◽  
Signed Rank ◽  
Fine Diamond ◽  
Before And After ◽  
Signed Rank Test ◽  
Lingual Brackets

The aim of the present study was to quantitatively assess changes in enamel roughness parameters before and after lingual bracket debonding. The lingual surface of 25 sound premolars extracted for orthodontic reasons was studied by 3D optical interferometric profilometry before and after debonding of lingual brackets following enamel finishing (with fine diamond) and polishing (with 12- and 20-fluted carbide burs). The roughness parameters tested were the amplitude parameters Sa and Sz, the hybrid parameter Sdr, and the functional parameters Sc and Sv. The parameter differences (after debonding-reference) were calculated, and statistical analysis was performed via a Wilcoxon signed-rank test. Statistically significantly higher values were observed in all the surface roughness parameters of enamel surfaces after finishing and polishing, with the mostly affected parameter being the Sdr. Under the conditions of the present study, the finishing and polishing instruments used after debonding of lingual noncustomized brackets created a surface texture rougher than the control in all the tested roughness parameters.

Comparison of the Friction and Wear Properties of PTFE Coatings under Vacuum Conditions before and after Gamma Irradiation

2011 ◽  
Vol 311-313 ◽  
pp. 1177-1181 ◽  
Author(s):  
Xing Dong Yuan ◽  
Bin Xu ◽  
Xiao Jie Yang ◽  
Hai Long Ma
Keyword(s):  
Friction Coefficient ◽  
Gamma Irradiation ◽  
Friction And Wear ◽  
Sliding Velocity ◽  
Wear Properties ◽  
Sliding Speed ◽  
Wear Process ◽  
Before And After ◽  
Three Stages ◽  
Friction And Wear Properties

The friction and wear properties of Polytetrafluoroethylene (PTFE) coatings before and after gamma irradiation were studied under vacuum conditions. Experimental results indicated that the friction and wear properties of PTFE coatings were improved by gamma irradiation. Results showed that the wear process of PTFE coatings before and after gamma irradiation consists of three stages. The steps for the irradiated PTFE are slightly longer than that for the non-irradiated samples. The friction coefficient of irradiated PTFE coatings reduces slightly compared to that of the non-irradiated samples. The friction coefficients of the PTFE coatings before and after gamma irradiation first increase with the increase of sliding velocity and then decrease with the increase of sliding velocity, and The friction coefficient of PTFE coatings before and after gamma irradiation decreases with the increase of load. The wear of irradiated PTFE coatings is slightly lower than that of non-irradiated PTFE coatings. The wear of PTFE coatings before and after gamma irradiation first decreases with the increase of sliding speed and then increases as the sliding speed increases. The wear of PTFE coatings first decreases with the increase of load and then increases with the increase of load. Scanning electron microscope (SEM) was utilized to investigate the worn surfaces.

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
Keyword(s):  
Surface Roughness ◽  
Surface Topography ◽  
Surface Profile ◽  
Wear Process ◽  
Equilibrium Surface ◽  
Important Stage ◽  
Before And After ◽  
3D Information

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.

scholarly journals Possibilities of applying motif group parameters for description roughness of turned surfaces

2018 ◽  
Vol 244 ◽  
pp. 01028
Author(s):  
Maciej Kowalski ◽  
Magdalena Wiśniewska ◽  
Paweł Karolczak ◽  
Jozef Holubjak
Keyword(s):  
Surface Roughness ◽  
Surface Structures ◽  
Roughness Parameters ◽  
Kinematic Parameters ◽  
Geometrical Structures ◽  
Iso Standards ◽  
Longitudinal Turning ◽  
Roughness Measurements

This article explores the methodology of assessing the applicability of roughness parameters from the motif group to the evaluation of one-way and periodic geometrical surface structures. The results of surface roughness measurements of aluminum samples turned with variable kinematic parameters were presented. Usability of using surface motifs in combination with selected parameters described in ISO standards for assessment of geometrical structures characteristic for longitudinal turning was shown.

Height-independent topographic parameters of worn surfaces

2011 ◽  
Vol 2 (1) ◽  
pp. 35-40
Author(s):  
I. Barányi ◽  
Á. Czifra ◽  
Gabor Kalácska
Keyword(s):  
Fractal Dimension ◽  
Surface Area ◽  
Friction And Wear ◽  
Area Ratio ◽  
Mean Square ◽  
Surface Area Ratio ◽  
Surface Microtopography ◽  
Steel Material ◽  
Before And After ◽  
Topographic Parameters

Surface microtopography plays a dual role in the course of friction and wear processes. It affectsthe contact and temperature conditions, and it undergoes significant changes in accordance with the wearmechanism. Fractal dimension (Df), root mean square gradient (Sdq), surface area ratio (Sdr) and surfacekurtosis (Sku) parameters of microtopographies provides opportunities for understanding more deeply thewear processes independently from the amplitude of the roughness. Wear experiments and surfaceroughness measurements before and after wear were performed. Investigations extended to wear in thecourse of the non-lubricated ferrodo-steel material pairs, and lubricated camshaft-bushing pairs.

Effect of Vanadium Addition on the Surface Roughness and Fatigue Crack Propagation in a Railroad Wheel Using Twin Disc Wear Test

2019 ◽  
Vol 391 ◽  
pp. 66-73 ◽  
Author(s):  
A.B. Rezende ◽  
G.A. Amorim ◽  
D.J. Minicucci ◽  
S.T. Fonseca ◽  
P.R. Mei
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Roughness ◽  
Wear Test ◽  
Railroad Wheel ◽  
Roughness Parameters ◽  
Small Cracks ◽  
Sliding Test ◽  
Roughness Measurements ◽  
Scanning Electron

To verify the effect of 0.13 % vanadium addition (% in weight) on the wear resistance of a railroad wheel steel with 0.7 % carbon, twin-disc rolling-sliding test were performed. These two steels were named 7V and 7C. The test discs were analyzed to verify the superficial conditions and wear mechanisms using SEM (Scanning Electron Microscopy) and roughness measurements. After 100,000 cycles running it was concluded that without the presence of debris, the 7V steel presented a reduction in 35 % the mass loss compared to 7C steel. For the 7V steel, in the test without debris, the discs presented small cracks (10 μm long), very near (3 μm deep) the surface, but in the test with the presence of debris, the disc surfaces presented delaminated material and long cracks (100 μm long) faraway from surface (up to 72 μm deep). The presence of debris also increased the roughness parameters in 7V steel: average Rz jumped from near 6 μm in the steel without debris to near 26 μm in the steel with debris.

Research on the Wear Process of High Speed Cutting Ni-Based Superalloy

2014 ◽  
Vol 800-801 ◽  
pp. 102-106
Author(s):  
Jun Zhou ◽  
Ming Pu Liu ◽  
Hong Qi Sun
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Cutting Force ◽  
Wear Mechanism ◽  
High Speed ◽  
Cutting Tool ◽  
Cutting Temperature ◽  
Wear Process ◽  
High Speed Cutting ◽  
Cutting Tool Wear

As the main method of high efficiency cutting Ni-based superalloy, high-speed cutting can not but intensify the cutting-tool wear for the high cutting force and cutting temperature. So, it is very necessary to study the process of cutting-tool wear and wear mechanism, especially, the effect of cutting-tool wear on the cutting force, cutting temperature and surface roughness of machined workpiece. In this paper, investigation of tool wear in high-speed cutting is proposed, the PCDTiAlN carbide insert is used in the experiment, the cutting-tool wear and the corresponding cutting force, cutting temperature and surface roughness of machined workpiece is detected. It indicates that the cutting force, cutting temperature and surface roughness of machined workpiece is changed corresponding the cutting-tool wear,the wear process of coated tool include the coated material wears and base material wears,the wear mechanism is complex. Key word: superalloy, high-speed cutting, tool wear, wear form ; .

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