The Study of Surface-Roughness Profiles of Fatigued Metals by Scanning Electron Microscopy

1982 ◽  
Vol 73 (1) ◽  
pp. 30-34
Author(s):  
Renhui Wang ◽  
Bernd Bauer ◽  
Haël Mughrabi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Roughness ◽  
Scanning Electron

scholarly journals Comparison of the Enamel Surface Roughness from Different Polishing Methods: Scanning Electron Microscopy and Atomic Force Microscopy Investigation

2020 ◽  
Vol 14 (02) ◽  
pp. 299-305
Author(s):  
Kiatanan Sugsompian ◽  
Ratchawan Tansalarak ◽  
Thosapol Piyapattamin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Enamel Surface ◽  
Similar Data ◽  
Force Microscopy ◽  
Atomic Force ◽  
Significant Difference ◽  
Scanning Electron

Abstract Objective This study aimed to compare the enamel surface roughness created by four polishing methods after debonding, by using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Materials and Methods Four experimental polishing groups (Sof-Lex disc, SD; sandblaster, SB; tungsten carbide bur, TB; and white stone bur, WB) and one control group were selected from 100 premolars (n = 20/group). The experimental teeth were bonded with a bracket, thermocycled, and debonded. Residual adhesive was removed by either of the respective methods. Pre and postdebonding root mean square (Rq) values were obtained from AFM evaluations. All specimens were examined and evaluated with SEM using a modified enamel surface index (modified ESI). Statistical Analysis Differences among the polishing methods were compared with analysis of variance and Fisher’s least significant difference test at p < 0.05. Results Both microscopic evaluations indicated that the surface with the greatest roughness herein belonged to the SD group, followed by that for SB, TB, and WB groups. AFM measurements indicated a maximum postdebonding Rq herein for the WB group and a significantly greater surface roughness for the TB and WB groups than for the SD and SB groups. Among the experimental groups, SEM followed by modified ESI evaluations revealed similar data to those obtained with AFM. Significant differences were seen among all paired groups, except for that between the SB and TB groups. Conclusion Within the limitations of this study, all four polishing methods were concluded to be clinically acceptable for removing residual orthodontic adhesives.

Morphological changes of Branched Ge Clusters caused by Diffusion Fields and Surface Roughness of Au Underlayer

1995 ◽  
Vol 407 ◽  
Author(s):  
A. Sugawara ◽  
T. Kikukawa ◽  
Y. Haga ◽  
O. Nittono
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Roughness ◽  
Diffusion Length ◽  
Morphological Changes ◽  
Evolution Mechanism ◽  
Branching Patterns ◽  
Scanning Electron

ABSTRACTThe formation of polycrystalline Ge clusters, during annealing of amorphous Ge/polycrystalline Au bilayers, has been studied by in-situ transmission and scanning electron microscopy. The experimentally observed generation of branching patterns, and the evolution mechanism of branches, are discussed on the basis of finite diffusion length aggregation simulations.

scholarly journals Bacterial Adhesion and Surface Roughness for Different Clinical Techniques for Acrylic Polymethyl Methacrylate

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Lucas Costa de Medeiros Dantas ◽  
João Paulo da Silva-Neto ◽  
Talita Souza Dantas ◽  
Lucas Zago Naves ◽  
Flávio Domingues das Neves ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Roughness ◽  
Bacterial Adhesion ◽  
Surface Finishing ◽  
Fabrication Method ◽  
The Mean ◽  
One Way Anova ◽  
Roughness Measurements ◽  
Scanning Electron

This study sought to assess the effect of different surface finishing and polishing protocols on the surface roughness and bacterial adhesion (S. sanguinis) to polymethyl methacrylates (PMMA). Fifty specimens were divided into 5 groups (n=10) according to their fabrication method and surface finishing protocol: LP (3 : 1 ratio and laboratory polishing), NF (Nealon technique and finishing), NP (Nealon technique and manual polishing), MF (3 : 1 ratio and manual finishing), and MP (3 : 1 ratio and manual polishing). For each group, five specimens were submitted to bacterial adhesion tests and analyzed by scanning electron microscopy (SEM). Two additional specimens were subjected to surface topography analysis by SEM and the remaining three specimens were subjected to surface roughness measurements. Data were compared by one-way ANOVA. The mean bacterial counts were as follows: NF,19.6±3.05; MP,5.36±2.08; NP,4.96±1.93; MF,7.36±2.45; and LP,1.56±0.62(CFU). The mean surface roughness values were as follows: NF,3.23±0.15; MP,0.52±0.05; NP,0.60±0.08; MF,2.69±0.12; and LP,0.07±0.02(μm). A reduction in the surface roughness was observed to be directly related to a decrease in bacterial adhesion. It was verified that the laboratory processing of PMMA might decrease the surface roughness and consequently the adhesion ofS. sanguinisto this material.

Scanning Electron Microscopy and Roughness Study of Dental Composite Degradation

2012 ◽  
Vol 18 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Luís Eduardo Silva Soares ◽  
Louise Ribeiro Cortez ◽  
Raquel de Oliveira Zarur ◽  
Airton Abrahão Martin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Roughness ◽  
Composite Resin ◽  
Morphological Changes ◽  
Soft Drink ◽  
Dental Composite ◽  
Control Group ◽  
Significant Difference ◽  
Scanning Electron

AbstractOur aim was to test the hypothesis that the use of mouthwashes, consumption of soft drinks, as well as the type of light curing unit (LCU), would change the surface roughness (Ra) and morphology of a nanofilled composite resin (Z350® 3M ESPE). Samples (80) were divided into eight groups: Halogen LCU, group 1, saliva (control); group 2, Pepsi Twist®; group 3, Listerine®; group 4, Colgate Plax®; LED LCU, group 5, saliva; group 6, Pepsi Twist®; group 7, Listerine®; group 8, Colgate Plax®. Ra values were measured at baseline, and after 7 and 14 days. One specimen of each group was prepared for scanning electron microscopy analysis after 14 days. The data were subjected to multifactor analysis of variance at a 95% confidence followed by Tukey's honestly significant difference post-hoc test. All the treatments resulted in morphological changes in composite resin surface, and the most significant change was in Pepsi Twist® groups. The samples of G6 had the greatest increase in Ra. The immersion of nanofilled resin in mouthwashes with alcohol and soft drink increases the surface roughness. Polymerization by halogen LCU (reduced light intensity) associated with alcohol contained mouthwash resulted in significant roughness on the composite.

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.

Er,Cr:YSGG laser surface treatment of gamma titanium aluminide: Scanning electron microscopy–energy-dispersive X-ray spectrometer analysis, wettability and Eikenella corrodens and Aggregatibacter actinomycetemcomitans bacteria count—in vitro study

2020 ◽  
Vol 234 (8) ◽  
pp. 769-783
Author(s):  
Maryam Koopaie ◽  
Ali Kia Darbandsari ◽  
Neda Hakimiha ◽  
Sajad Kolahdooz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Roughness ◽  
Surface Treatment ◽  
Laser Surface ◽  
Energy Dispersive ◽  
Laser Surface Treatment ◽  
Eikenella Corrodens ◽  
X Ray ◽  
Scanning Electron

Dental implants play an important role in oral health. Titanium dental implants must endure the complex microflora environment of the oral cavity. Moreover, bacterial infections have been considered as one of the most important factors of implant failure. The issue of dental improvement through modification of chemical composition and surface treatment has received considerable critical attention. γ-TiAl as a novo biocompatible material revealed a slower corrosion rate in biological media rather Ti-6Al-4V. The objective of this study is to investigate the effect of Er,Cr:YSGG laser on γ-TiAl in comparison with sandblasted and acid-etched samples as the control groups and machined samples. Wettability, surface roughness, surface topography, scanning electron microscopy–energy dispersive X-ray spectrometer analysis of surface and subsurface of samples were investigated and bacteria counts of two periodontal bacterial strains ( Aggregatibacter actinomycetemcomitans and Eikenella corrodens) were evaluated on the Er,Cr:YSGG laser surface-treated sandblasted and acid-etched and machined samples. The results of this investigation show that Er,Cr:YSGG laser surface treatment affects surface roughness, surface topography, wettability, chemical composition of the surface and bacteria count. Scanning electron microscopy–energy dispersive X-ray spectrometer analysis of the sample revealed the increment of titanium and oxygen content and reduction of aluminum content in the surface and subsurface layer. A. actinomycetemcomitans and E. corrodens count were found from the lowest level to highest in the sandblasted and acid-etched samples, laser samples and machined samples, respectively. Using controlled parameters of Er,Cr:YSGG laser ensured no significant adverse alteration. The findings to emerge from this study revealed the significant correlation between microbial count and wettability. Furthermore, the contact angle strongly correlated with surface roughness.

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