Skip Nav Destination
Close Modal
Update search
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
Filter
- Title
- Authors
- Author Affiliations
- Full Text
- Abstract
- Keywords
- DOI
- ISBN
- EISBN
- Issue
- ISSN
- EISSN
- Volume
- References
NARROW
Format
Topics
Subjects
Article Type
Volume Subject Area
Date
Availability
1-3 of 3
R. Oltra
Close
Follow your search
Access your saved searches in your account
Would you like to receive an alert when new items match your search?
Sort by
Proceedings Papers
ITSC 2007, Thermal Spray 2007: Proceedings from the International Thermal Spray Conference, 335-340, May 14–16, 2007,
Abstract
View Paper
PDF
The aim of this work was to study the modifications induced by 10 ns single or cumulative pulses of a Q-switched Nd:YAG laser emitting in the near-infrared (λ = 1064 nm) on a pure aluminum surface with a laser energy density leading to a regime of interaction below the material ablation. The influence of these laser substrate pre-treatments on the mechanical behavior of an 83 µm thick alumina plasma sprayed coating was observed by evaluating the integrity of the coating/substrate interface with a "laser-ultrasonic method" thanks to a special set up using a probe laser interferometer. An increase in the alumina coating adhesion considering cumulative pulses for a laser energy density of 0.7 J/cm 2 was observed above 100 laser pulses. The highest adhesion was obtained for a laser treatment considering 1000 shots. For a single pulse laser treatment, this increase was found applying an energy density of 1.8 J/cm 2 . These results were correlated with the observation of modifications on topography and morphology of the aluminum surface after laser irradiations using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results showed that the improvement of the adhesion of the plasma-sprayed alumina coatings was correlated to changes of the aluminum oxide morphology.
Proceedings Papers
ITSC 2005, Thermal Spray 2005: Proceedings from the International Thermal Spray Conference, 1021-1026, May 2–4, 2005,
Abstract
View Paper
PDF
In the PROTAL process, a pulsed (10ns) laser irradiation is introduced to prepare the surface simultaneously to the thermal spraying process. The purpose of the laser pre-treatment is to eliminate the contaminants and generate a surface condition favorable to the coating adhesion. This study aims at clarifying the fundamental aspects of laser irradiation effects on metallic substrates. The broad technical applications, which involves various surface conditions, may lead to different phenomena and hence limit our comprehensive understanding of the laser-material interaction. Therefore, all specimens were mechanically polished to a mirror state before the laser treatment, which allows the same surface state. Both morphological and chemical surface modifications were investigated by optical microscopy, SEM observation, roughness measurements. Formation of dispersed craters, which takes place at the superficial defects location, dominates the surface modifications due to localized laser ablation.
Proceedings Papers
ITSC 2001, Thermal Spray 2001: Proceedings from the International Thermal Spray Conference, 1229-1234, May 28–30, 2001,
Abstract
View Paper
PDF
In this study, a new laser based technique was evaluated for the characterization of plasma-sprayed oxide coatings. It uses the contactless laser generation and detection of ultrasonic waves in the bi-layered systems. For this purpose, a nanosecond pulsed Nd:YAG laser (λ : 1064 nm, τ =14 ns) was used for irradiating the ceramic coating, whilst the longitudinal displacements of the rear surface of the metallic substrate were detected at the epicenter using a laser heterodyne interferometer. The acoustic signal recorded at the rear surface of the substrate was found to be characteristic of the different events taking place within the irradiated system. In this way, the longitudinal wave velocity, the porosity, as well as the Young's modulus of the coatings can be easily determined, whilst the coating/ substrate adhesion strength can be calculated, taking into account both the thermal, as well as the acoustic effects of the laser radiation. The proposed technique was applied to alumina coatings deposited onto stainless steel coupons by Atmospheric Plasma Spraying and the results were found to be in accordance with those obtained by the techniques commonly used for testing thermal spray coatings (interfacial indentation test, porosity measurement, etc.).