A5008024345- Laser Material Processing Techniques
- Laser-induced spectroscopy and plasma
- Metal and Thin Film Mechanics
- Glass properties and applications
- Advanced Surface Polishing Techniques
- Metallic Glasses and Amorphous Alloys
- Welding Techniques and Residual Stresses
- Force Microscopy Techniques and Applications
- Structural Analysis of Composite Materials
- Dental materials and restorations
- Bone Tissue Engineering Materials
- High-pressure geophysics and materials
- Diamond and Carbon-based Materials Research
- Material Science and Thermodynamics
- Integrated Circuits and Semiconductor Failure Analysis
- Surface Roughness and Optical Measurements
- Dental Implant Techniques and Outcomes
- High-Temperature Coating Behaviors
- Phase-change materials and chalcogenides
- Laser-Plasma Interactions and Diagnostics
- High-Velocity Impact and Material Behavior
- Fatigue and fracture mechanics
- Mineralogy and Gemology Studies
- Numerical methods in engineering
- Adhesion, Friction, and Surface Interactions
Institut de Physique de Rennes
2014-2019
Centre National de la Recherche Scientifique
2004-2018
Université de Rennes
2013-2014
École Nationale Supérieure de Mécanique et d'Aérotechnique
2009-2011
Université de Poitiers
2011
École nationale supérieure de techniques avancées Bretagne
2011
École nationale supérieure d'arts et métiers
2009-2011
ParisTech
2009-2011
Université de Bretagne Occidentale
2011
Centre des Matériaux
2011
This paper proposes a state-of-the-art laser adhesion test. It consists of testing material interfaces with laser-driven shock wave. Since the first demonstration in 1980s by Vossen, many studies and developments have been done. presents recent experiments on basic physics involved. Results show ability technique to perform quantitative test for wide range materials configurations. Edge effect principle ultra-short wave give perspectives new applications multi-layer combination material....
Spallation induced by a laser driven shock has been studied for two decades on time scales of nanosecond order. The evolution technologies now opens access to sources whose pulse duration is under the picosecond, corresponding characteristic times numerous microscopic phenomena. In this ultra-short irradiation regime, spallation experiments have performed with time-resolved measurements free surface. These measurements, complemented post-test observations, compared numerical simulations...
The highly visible and infrared (up to 6 μm) transparent Sr3Al2O6 polycrystalline ceramic was obtained by full crystallization of the corresponding glass composition. synthesis direct congruent processes are described, material transparency is discussed in light its microstructure. This new exhibits a high density (i.e., complete absence porosity) micrometer-scale crystallites with very thin grain boundaries. These microstructural characteristics, inherent preparation method, minimize...
Abstract An adhesion test procedure applied to plasma‐sprayed hydroxyapatite (HA) coatings measure the “LASAT threshold” (LAser Shock Adhesion test) is described. The good repeatability and minimal discrepancy of laser‐driven data were ascertained for conventional plasma sprayed HA coatings. As a further demonstration, was with diverse characteristics on ceramic/metal interface. Different preheating grit blasting conditions presence thick Ti sublayer or thin TiO 2 layer prepared by oxidation...
This article deals with the gas effect on percussion laser drilling in ms pulse duration range. On one hand, flow of assistance jet is investigated and without a target using strioscopy setup Pitot’s tube. By this way, position shock waves supersonic near surface revealed. From characterization, distance between exit nozzle can be optimized to induce higher pressure protect optics from liquid ejection. other metal vapor jets irradiated are observed high-speed camera (100 000 Img/sec)....
We present a new heterodyne velocimeter setup embedding second low‐power frequency‐tunable laser acting as local oscillator. thus double the overall bandwidth of system and we make tuning power levels easier, to achieve good matching between electric signal dynamics detector. Recently, used this onto metallic target shock driven by high laser. The aim is test ability means reveal propagation effects into materials under extremely strain rate with fast variations loading evolution. Spallation...
Laser-shock experiments were performed on a ternary bulk metallic glass. A spalling process was studied through post-mortem analyses conducted recovered sample and spall. Scanning electron microscopy magnification of fracture surfaces revealed the presence peculiar feature known as cup-cone. Cups are found surface while cones observed Two distinct regions can be cups cones: smooth viscous-like region in center flat one with large vein-pattern periphery. Energy dispersive spectroscopy...
Silica glass is known to exhibit permanent changes in density under very high pressures. These may reach 21%. The sharp indentation test develops pressures underneath the indenter that trigger densification. Recently, we have proposed a constitutive modeling of pressure-induced process accounting for its salient features: densification threshold, hardening, saturation densifica- tion and increase elastic moduli. We examine this paper possibility densi- fication could be only mechanism...
The adhesive strength between a coating and substrate is an important factor that characterizes the quality of thermally sprayed Hydroxyapatite (HA) coatings such as those for biomedical applications. In this study was evaluated by LAser Shock Adhesion Test (LASAT) technique. LASAT developed to be suitable determining coating-substrate adhesion. This deals with hydroxyapatite on Ti-based alloy produced atmospheric plasma spraying. order discuss influence spray condition strength, different...
To drill sub-millimeters holes, laser percussion drilling has been a well-established and recognized industrial process for many years. However, inherent factors such as the source instability, number of parameters complexity phenomenon are still making physical understanding this very difficult. And in particular gas effect, which is several models, an element dynamic drilling. This paper deals with first experimental investigations concerning regime performed new HL201P (Nd:Yag) from...
To drill sub-millimeters holes one of the way is laser drilling. Laser drilling a well-established industrial process for tens years. However this doesn't get well under control. The influence inherent factors are not still understood. This article deals with gas effect on We investigate flow an assist without and target help strioscopy set up. By way, we see position shock waves in supersonic jet surface. inspect nature metal vapor from irradiated these different flows process.
Basically, thermal spray and laser processing can be considered as half brothers since they show many common features due to the use of a (more or less) high-energy source for both. Their combination therefore very fruitful prominent achieve coatings, which results in their most recent advanced applications. In materials development story, will thus have moved from cutting coating. This keynote presentation focuses on recently-developed coupling cold spray). this dual process, gun is...
MCrAlY-typed coatings are conventional for applications to land-based turbines against hightemperature oxidation and corrosion. However, improvements still currently expected from innovations in the coating process and/or selection of starting materials. Both types were studied present work. The former consisted cold spray as a substitute plasma which is conventionally used process. latter developing mechanically-alloyed powders be suitable targeted application especially. In this study,...
Understanding and modeling the behavior of glass is an issue for certain aeronautical, military civil applications. For example, parts satellites shuttles are made glasses. During their lifetime, they subjected to potentially damaging high velocity impacts. To determine these structures during after impact we used instrumented laser driven shock loading performed on power intensity facilities. Transverse shadowgraphs front wave propagating inside transparent material collected at different...
The determination of the contact area is a key step to derive mechanical properties such as hardness or an elastic modulus by instrumented indentation testing. Two families procedures are dedicated extracting this area: on one hand, post mortem measurements that require residual imprint imaging, and other direct methods only rely load vs. penetration depth curve. With development built-in scanning probe microscopy imaging capabilities atomic force tip microscopy, last generation devices have...
To face High Velocity Impacts, the aerospace industry has a constant need for innovative materials that can be used as debris shielding components. Bulk Metallic Glasses (BMG) revealed interesting mechanical properties in case of static and quasi-static loading conditions: high elasticity, toughness, low density fracture threshold. The department Mechanics Glass Institute Physics Rennes conducted laser shock experiments (ELFIE facility) to study compositional effects on behavior ternary...