scholarly journals Nanosecond laser pulses for aluminum and copper drilling

2018 ◽  
Vol 16 (36) ◽  
pp. 47-52
Author(s):  
Walid K. Hamoudi
Keyword(s):  
Thermal Conductivity ◽  
Melting Point ◽  
Laser Pulse ◽  
Power Density ◽  
Laser Power ◽  
Laser Pulses ◽  
Laser Power Density ◽  
Nanosecond Laser ◽  
Operating Wavelength ◽  
Nanosecond Laser Pulses

Nd:YAG laser pulses of 9 nanosecond pulse duration and operating wavelength at 1.06 μm, were utilized to drill high thermal conductivity and high reflectivity aluminum and copper foils. The results showed a dependence of drilled holes characteristics on laser power density and the number of laser pulses used. Drilled depth of 74 ϻm was obtained in aluminum at 11.036×108 W/cm2 of laser power density. Due to its higher melting point, copper required higher laser power density and/or larger number of laser pulses to melt, and a maximum depth of 25 μm was reached at 13.46×108 W/cm2 using single laser pulse.

TREATMENT OF ALUMINUM ALLOYS SURFACE BY NANOSECOND LASER

2018 ◽  
Vol 25 (04) ◽  
pp. 1850079 ◽  
Author(s):  
MOHAMED EZZAT ◽  
M. A. EL-WAILY ◽  
M. ABDEL-RAHMAN ◽  
YEHEA ISMAIL
Keyword(s):  
Power Density ◽  
Laser Power ◽  
Defect Density ◽  
Industrial Applications ◽  
Laser Power Density ◽  
Aluminum Surface ◽  
Nanosecond Laser ◽  
Sem Images ◽  
Minimum Diameter ◽  
Maximum Value

Aluminum and its alloys are widely used in our daily life because of their desirable physical properties. Improving the quality of Al-alloys surface layers is required for industrial applications. Nd: YAG pulsed Nanosecond Laser was used in irradiating aluminum 1100 alloy to study the surface morphology and hardness properties. Scanning Electron Microscope (SEM) images reveal the presence of small holes with different diameters that are produced by the irradiation of Aluminum alloy surfaces with different laser power densities. The diameters of the produced holes are decreased gradually by increasing the laser power density. Minimum diameter of about 1.84[Formula: see text][Formula: see text]m is obtained after irradiating the aluminum surface with 1256.04[Formula: see text]MW/cm2 at which semi-periodic holes-like pattern were produced. An increase in the Vickers microhardness values was obtained until the maximum value of 28 HV was reached at laser power density of 750.16[Formula: see text]MW/cm2. After reaching the maximum value, a fast decrease in the microhardness values was observed. Such changes in microhardness values maybe attributed to the lattice disorder and the change in the defect density produced by laser irradiation.

Time-Resolved Experimental Study of Silicon Carbide Ablation by Infrared Nanosecond Laser Pulses

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Yibo Gao ◽  
Yun Zhou ◽  
Benxin Wu ◽  
Sha Tao ◽  
Ronald L. Jacobsen ◽  
...  
Keyword(s):  
Experimental Study ◽  
Silicon Carbide ◽  
Laser Pulse ◽  
Material Removal ◽  
Laser Pulses ◽  
Nanosecond Laser ◽  
Removal Mechanism ◽  
Material Removal Mechanism ◽  
Time Resolved ◽  
Nanosecond Laser Pulses

Silicon carbide, due to its unique properties, has many promising applications in optics, electronics, and other areas. However, it is difficult to micromachine using mechanical approaches due to its brittleness and high hardness. Laser ablation can potentially provide a good solution for silicon carbide micromachining. However, previous studies of silicon carbide ablation by nanosecond laser pulses at infrared wavelengths are very limited on material removal mechanism, and the mechanism has not been well understood. In this paper, experimental study is performed for silicon carbide ablation by 1064 nm and 200 ns laser pulses through both nanosecond time-resolved in situ observation and laser-ablated workpiece characterization. This study shows that the material removal mechanism is surface vaporization, followed by liquid ejection (which becomes clearly observable at around 1 μs after the laser pulse starts). It has been found that the liquid ejection is very unlikely due to phase explosion. This study also shows that the radiation intensity of laser-induced plasma during silicon carbide ablation does not have a uniform spatial distribution, and the distribution also changes very obviously when the laser pulse ends.

scholarly journals Influence of Saturation Phenomena on Laser-Excited Atomic Fluorescence Flame Spectrometry

1973 ◽  
Vol 28 (2) ◽  
pp. 273-279
Author(s):  
J. Kühl ◽  
S. Neumann ◽  
M. Kriese
Keyword(s):  
Power Density ◽  
Laser Power ◽  
Atomic Emission ◽  
Equation Model ◽  
Laser Power Density ◽  
Atomic Level ◽  
Dye Laser ◽  
Atomic Fluorescence ◽  
Emission Flame ◽  
Flame Spectrometry

Using a simple rate equation model, the laser power density Ic necessary to reach 50% of the saturation limited population of the excited atomic level under typical flame conditions is calculated. For Na atoms aspirated into the flame a saturating power density for irradiation with a narrow dye laser line (bandwidth 0.033 Å) of Ic ~ 0.4 kW/cm2 was determined. With the aid of a dye laser with an appropriate laser power density, analytical curves for Na were measured yielding a detection limit of 0.2 ng/ml. This sensitivity is comparable with the best results obtained by atomic emission flame spectrometry.

Formation of Periodical Sub-Micron Sized Structures on Silicon by Interfered Nanosecond Laser Pulses

2010 ◽  
Vol 97-101 ◽  
pp. 3803-3806
Author(s):  
Yong Xiang Hu ◽  
Heng Zhang ◽  
Zheng Qiang Yao
Keyword(s):  
Cost Effective ◽  
Laser Pulses ◽  
Laser Beams ◽  
Nanosecond Laser ◽  
Effective Technique ◽  
First Order ◽  
Direct Fabrication ◽  
Cost Effective Technique ◽  
Nanosecond Laser Pulses ◽  
Micro Structuring

Laser interference micro-structuring is a relatively efficient and cost-effective technique for fabricating periodical micro-nano-structuring surfaces. The direct fabrication of sub-micron sized dot array on silicon was performed by four interfering nanosecond laser beams with a diffractive beam splitter. The mechanism to form the dot array was analyzed and it was found that the obtained conical dot array had a negative shape of the interference pattern of four laser beams. A second-order peak between two first-order peaks also occurred due to the liquid-solid expansion.

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