Mechanisms of melt droplets and solid-particle ejection from a target surface by pulsed laser action

1995 ◽  
Vol 61 (1) ◽  
pp. 81-86 ◽  
Author(s):  
A. B. Brailovsky ◽  
S. V. Gaponov ◽  
V. I. Luchin
Keyword(s):  
Solid Particle ◽  
Laser Action ◽  
Pulsed Laser ◽  
Target Surface ◽  
Particle Ejection

Mechanisms of melt droplets and solid-particle ejection from a target surface by pulsed laser action

1995 ◽  
Vol 61 (1) ◽  
pp. 81-86 ◽  
Author(s):  
A. B. Brailovsky ◽  
S. V. Gaponov ◽  
V. I. Luchin
Keyword(s):  
Solid Particle ◽  
Laser Action ◽  
Pulsed Laser ◽  
Target Surface ◽  
Particle Ejection

A Model for the Effect of Velocity on Erosion of N80 Steel Tubing due to the Normal Impingement of Solid Particles

1992 ◽  
Vol 114 (1) ◽  
pp. 54-64 ◽  
Author(s):  
D. P. Chase ◽  
E. F. Rybicki ◽  
J. R. Shadley
Keyword(s):  
Solid Particle ◽  
Computational Study ◽  
Target Material ◽  
Target Surface ◽  
American Petroleum Institute ◽  
Solid Particles ◽  
Unknown Coefficient ◽  
Conservation Of Energy ◽  
Carrier Fluid ◽  
Erosion Behavior

As part of a combined experimental and computational study of erosion for gas and oil production conditions, a semi-empirical model has been developed to predict erosion ratio behaviors of metals due to solid particle impingement. One use of the model will be to reduce the total number of experiments needed to characterize erosion behavior. The model represents material property information associated with both the target material and the impinging particles, as well as impingement speed. Five different models are examined in terms of ability to predict erosion ratio behavior as a function of impingement speed. The model selected is based on a conservation of energy formulation and fracture mechanics considerations to predict the amount of material removed due to solid particle impingement. The resulting equation to predict the erosion ratio for a given particle size contains one unknown coefficient which is determined through comparison with experimental data. Illustrative examples are presented for data for two different sizes of glass bead solid particles in an oil carrier fluid impinging on an API (American Petroleum Institute) N80 grade steel target at an impingement angle 90 deg to the target surface. Using erosion data at one impingement speed to determine the unknown coefficient, the model was used to predict erosion behavior at a range of other speeds. Good agreement between the erosion ratio data and the values predicted by the model were found for two solid particle sizes. Recommendations for expanding the capabilities of the model are pointed out.

scholarly journals Influence of parameters of impulse laser impact on the formation of the gradient of the structure of porous titanium powder

2018 ◽  
pp. 88-94
Author(s):  
D. V. Minko
Keyword(s):  
Laser Radiation ◽  
Titanium Powder ◽  
Structural Characteristics ◽  
Selective Laser Sintering ◽  
Light Flux ◽  
Laser Action ◽  
Pulsed Laser ◽  
Powder Materials ◽  
Solid Core ◽  
Powder Particles

The possibility of selective laser sintering of graded porous and compactly porous structures by surface fusion of powder particles is demonstrated while maintaining a solid core, which leads to the formation of interparticle contacts in the presence of a liquid phase. The interaction of the light flux of the laser pulse with the surface of the powder particles under multiple reflection is considered. It is shown that the effect of single pulses of laser radiation leads to the formation of sintered structural elements of a powder material having a diameter approximately equal to the diameter of the focal spot. Technological regimes of pulsed laser action are established at which steady contact formation of titanium powder particles of the fractional compositions under study occurs. The possibility of obtaining powder materials with a gradient structure by controlling the parameters of pulsed laser action is experimentally demonstrated. It was found that accurate dosing of thermal energy and the number of pulses of laser radiation makes it possible to minimize shrinkage of powder layers in the absence of particle conglomeration, to control the structural characteristics and properties of products, to preserve the microstructure and phase composition of the initial materials.

Surface temperature measurements during pulsed laser action on metallic and ceramic materials

1996 ◽  
Vol 96-98 ◽  
pp. 505-512 ◽  
Author(s):  
M.B. Ignatiev ◽  
I.Yu. Smurov ◽  
G. Flamant ◽  
V.N. Senchenko
Keyword(s):  
Surface Temperature ◽  
Laser Action ◽  
Pulsed Laser ◽  
Ceramic Materials ◽  
Temperature Measurements

scholarly journals Pulsed Laser Deposition of Bismuth Vanadate Thin Films—The Effect of Oxygen Pressure on the Morphology, Composition, and Photoelectrochemical Performance

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1360
Author(s):  
Konrad Trzciński ◽  
Mariusz Szkoda ◽  
Maria Gazda ◽  
Jakub Karczewski ◽  
Adam Cenian ◽  
...  
Keyword(s):  
Pulsed Laser Deposition ◽  
Oxygen Pressure ◽  
Bulk Heterojunction ◽  
Pulsed Laser ◽  
Target Surface ◽  
Thin Layers ◽  
Bismuth Vanadate ◽  
Laser Deposition ◽  
Photoelectrochemical Performance ◽  
Breakdown Spectroscopy

Thin layers of bismuth vanadate were deposited using the pulsed laser deposition technique on commercially available FTO (fluorine-doped tin oxide) substrates. Films were sputtered from a sintered, monoclinic BiVO4 pellet, acting as the target, under various oxygen pressures (from 0.1 to 2 mbar), while the laser beam was perpendicular to the target surface and parallel to the FTO substrate. The oxygen pressure strongly affects the morphology and the composition of films observed as a Bi:V ratio gradient along the layer deposited on the substrate. Despite BiVO4, two other phases were detected using XRD (X-ray diffraction) and Raman spectroscopy—V2O5 and Bi4V2O11. The V-rich region of the samples deposited under low and intermediate oxygen pressures was covered by V2O5 longitudinal structures protruding from BiVO4 film. Higher oxygen pressure leads to the formation of Bi4V2O11@BiVO4 bulk heterojunction. The presented results suggest that the ablation of the target leads to the plasma formation, where Bi and V containing ions can be spatially separated due to the interactions with oxygen molecules. In order to study the phenomenon more thoroughly, laser-induced breakdown spectroscopy measurements were performed. Then, obtained electrodes were used as photoanodes for photoelectrochemical water splitting. The highest photocurrent was achieved for films deposited under 1 mbar O2 pressure and reached 1 mA cm−2 at about 0.8 V vs Ag/AgCl (3 M KCl). It was shown that V2O5 on the top of BiVO4 decreases its photoactivity, while the presence of a bulk Bi4V2O11@BiVO4 heterojunction is beneficial in water photooxidation.

scholarly journals Formation of microcrystals under the influence of femtosecond laser radiation on carbon samples in liquid nitrogen

2019 ◽  
Vol 220 ◽  
pp. 02005
Author(s):  
Kirill Khorkov ◽  
Dmitry Kochuev ◽  
Anton Chernikov ◽  
Valery Prokoshev ◽  
Sergey Arakelian
Keyword(s):  
Experimental Study ◽  
Laser Radiation ◽  
Liquid Nitrogen ◽  
Subsurface Layer ◽  
Laser Action ◽  
Target Surface ◽  
Femtosecond Laser Radiation ◽  
Carbon Target ◽  
Direct Laser ◽  
Temperature And Pressure

In this paper, we present the results of an experimental study of the carbon microcrystals formation by direct laser action on the carbon target surface at temperature of liquid nitrogen. It is demonstrated that the formation of microcrystals occurs in the subsurface layer and is caused by the achievement of critical temperature and pressure.

Excimer Laser Ablation of Silicon at High Temperature

1998 ◽  
Vol 526 ◽  
Author(s):  
Y.F. Zhang ◽  
Y.H. Tang ◽  
C. S. Lee ◽  
N. Wang ◽  
I. Bello ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Laser Beam ◽  
Pulsed Laser ◽  
Target Surface ◽  
Si Nanowires ◽  
Beam Direction ◽  
Excimer Laser Ablation ◽  
Deep Channel ◽  
Porous Skeleton ◽  
Si Nanostructures

AbstractPulsed laser ablation of granulated Si target was carried out at 1200 °C in an Ar atmosphere. Multishot ablated target surface forms intensity dependent features, including porous, skeleton, and columnar structures. Very long columnar structures were observed when the angle of the target surface with respect to the direction of the laser beam was small. Evidence on preferable remove of smaller particles has been observed. Formation of the columnar structures started from the biggest particles at the surface and grew deeper, straight in the laser beam direction, by consuming the removed Si species from the deep channel between columns. The Si species ablated off the granulated Si target deposited as Si nanowires or nanoparticles down stream of the Ar flow. Significant decrease in the deposition rate of Si nanostructures has been observed upon the formation of the columnar structures at the target surface.

Effect of the dynamic absorptance of a metallic target surface on pulsed laser ablation

2006 ◽  
Vol 203 (5) ◽  
pp. 906-918 ◽  
Author(s):  
Li Li ◽  
Duanming Zhang ◽  
Zhihua Li ◽  
Li Guan ◽  
Xinyu Tan ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Target Surface ◽  
Pulsed Laser Ablation ◽  
Metallic Target
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