Influence of chemical composition and prior microstructure on diode laser hardening of railroad steels

Purpose: of these researches was to investigate the influence of thermal cycles recording conditions and comparing them with the calculated by FEM. This approach allows proposing a new way of determining the technological conditions of the process, based on numerical analyses. Design/methodology/approach: Thermal cycles of high power diode laser hardening and remelting was recorded and calculated by FEM. Results of metallographic examinations were compared with numerical simulations results, as well as the thermographic pictures. Acquisition errors during the thermal cycles were also defined. Findings: Due to the fact that the it was used FEM, comparison of the numerical analyses with real test results was performed for laser hardening and remelting process. Research limitations/implications: For complete information it is needed to collect bigger database of the results and prepare also hardness calculation model for WCL steel. Practical implications: The result of the presented work is to signal a methodology that allows obtaining information on the impact of the parameters of the laser hardening and remelting process on the properties of the treated samples. Not without significance is the fact that the use of FEM eliminates in this case a lot of errors that in real tests can distort the result. Originality/value: The researches were provided for high power diode laser hardening and remelting. The influence of heat input on layers properties and theirs structure was defined. Results were compared with thermographic pictures and calculated cases.

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Chemical Composition of Electron Beam Produced Air Plasma by Means of Tunable Diode Laser Spectroscopy and Numerical Simulation

2007 IEEE 34th International Conference on Plasma Science (ICOPS) ◽

10.1109/ppps.2007.4345753 ◽

2007 ◽

Author(s):

Anna Yu. Serdyuchenko ◽

Megan V. Seeley ◽

Quinn J. Sinnott ◽

Robert J. Vidmar

Keyword(s):

Numerical Simulation ◽

Electron Beam ◽

Chemical Composition ◽

Diode Laser ◽

Laser Spectroscopy ◽

Tunable Diode Laser ◽

Air Plasma ◽

Tunable Diode Laser Spectroscopy ◽

Diode Laser Spectroscopy

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Alterations in Surface Roughness and Chemical Characteristics of Sandblasted and Acid-Etched Titanium Implants after Irradiation with Different Diode Lasers

Applied Sciences ◽

10.3390/app10124167 ◽

2020 ◽

Vol 10 (12) ◽

pp. 4167 ◽

Cited By ~ 1

Author(s):

Hak-Ki Kim ◽

Su-Yeon Park ◽

Keunbada Son ◽

Yong-Gun Kim ◽

Won-Jae Yu ◽

...

Keyword(s):

Surface Roughness ◽

Chemical Composition ◽

Diode Laser ◽

Titanium Surface ◽

Diode Lasers ◽

Weight Percent ◽

Titanium Implants ◽

Significant Difference ◽

Probe Microscope ◽

The Mean

The purpose of this study was to evaluate the effects of diode laser irradiation with different wavelengths on the surface roughness (Ra) and chemical composition of sandblasted and acid-etched (SLA) titanium implants. Three types of diode lasers with different wavelengths were irradiated on the titanium implants at output powers of 1.0, 2.0, and 3.0 W. The mean Ra values for all spots were measured using a scanning probe microscope. Analysis of variance tests were performed to verify the differences in the Ra between groups according to the type of lasers or power out (α = 0.05). For analyzing chemical composition, atomic and weight percent ratios of titanium, oxygen, and carbon were measured using energy-dispersive spectrometry (EDS). The mean Ra of titanium disc was higher in the 3.0-W output than in 1.0-W or 2.0-W output, but there was no statistically significant difference (p > 0.05). In EDS analysis, it was difficult to find a clear difference in the titanium, oxygen, and carbon element ratios between the laser-irradiated and nonirradiated groups. The irradiation of diode laser with 1.0, 2.0, and 3.0 W output for 15 s decontaminated the SLA titanium surface without damage. However, additional clinical trials will be needed to verify the results of the present study.

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The Prevention of Implant Surface Alterations in the Treatment of Peri-Implantitis: Comparison of Three Different Mechanical and Physical Treatments

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17082624 ◽

2020 ◽

Vol 17 (8) ◽

pp. 2624 ◽

Cited By ~ 4

Author(s):

Marco Lollobrigida ◽

Lorenzo Fortunato ◽

Giorgio Serafini ◽

Giulia Mazzucchi ◽

Giuseppina Bozzuto ◽

...

Keyword(s):

Chemical Composition ◽

Surface Morphology ◽

Diode Laser ◽

Photoelectron Spectroscopy ◽

Microscopic Analysis ◽

Implant Surface ◽

Primary Means ◽

Surface Physicochemical Properties ◽

Physical Treatments ◽

A Minor

The surgical treatment of peri-implantitis is currently based on the removal of biofilms from the implant surface by primary means of mechanical and physical treatments. However, such approaches often determine some alterations of the implant surface with detrimental effects on re-osseointegration. This study aims to evaluate the effects of four different mechanical and physical treatments on titanium samples with moderately rough surface. Air powder abrasion (AP) with glycine powder, a titanium brush (TB) and a diode laser at 3 W (L3) and 4 W (L4) were tested. Surface morphology, roughness and chemical composition were then assessed by scanning electron microscope (SEM), white light interferometer and X-ray photoelectron spectroscopy (XPS), respectively. The microscopic analysis revealed significant alterations in surface morphology on TB samples, while AP and L3 had only a minor or null impact. L4 samples revealed signs of overheating due to the excessive power. Nevertheless, the overall roughness of the samples was not significantly altered in terms of roughness parameters. Similarly, surface chemical composition was not significantly affected by the treatments. Among the treatments tested in this study, air powder abrasion with glycine powder and 3 W diode laser had the lowest impact on surface physicochemical properties.

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