Measurement of scattering laser energy density distribution in optical extinctive chambers based on CCD imaging method

2016 ◽  
Keyword(s):  
Energy Density ◽  
Density Distribution ◽  
Laser Energy ◽  
Laser Energy Density ◽  
Imaging Method ◽  
Energy Density Distribution ◽  
Ccd Imaging

Study on the Testing System of Far-Field Laser Energy Density Distribution

2012 ◽  
Vol 229-231 ◽  
pp. 1338-1342
Author(s):  
Xu Yang ◽  
Lu Song ◽  
Jin Duan
Keyword(s):  
Energy Density ◽  
Density Distribution ◽  
Measurement Errors ◽  
Laser Energy ◽  
Target Surface ◽  
Laser Spot ◽  
Laser Energy Density ◽  
Testing System ◽  
Far Field ◽  
Energy Density Distribution

This study designs and develops a set of far-field laser spot energy testing system based on energy density detecting array. Through installing energy density detectors on the characteristic location of energy density target, the practical value of laser’s energy could be adopted. Meanwhile, by the use of visible light image equipment, the energy density distribution image of laser spot with a wavelength of 532nm on target surface could be obtained. After that, the energy density of each spot on the target surface as well as the energy density distribution have been figured out by fusing the grey level of laser spot image with the practical energy value detected by laser energy probes. The result shows that this system, which is simple, reliable, and available for the far-field laser energy density measurement under all circumstances, is capable of precisely measuring the far-field laser energy distribution with more than 1km with few measurement errors.

Measurement facility for the relative radiation energy density distribution for pulse-periodic lasers

1988 ◽  
Vol 31 (10) ◽  
pp. 966-967
Author(s):  
V. I. Andreev ◽  
A. P. Palivoda ◽  
S. P. Fetisov ◽  
N. V. Shalomeeva ◽  
V. A. Yakovlev
Keyword(s):  
Energy Density ◽  
Density Distribution ◽  
Radiation Energy ◽  
Measurement Facility ◽  
Radiation Energy Density ◽  
Energy Density Distribution

Fundamentals of radiation heat transfer in AlSi10Mg powder bed during selective laser melting

2019 ◽  
Vol 25 (9) ◽  
pp. 1506-1515 ◽  
Author(s):  
Pei Wei ◽  
Zhengying Wei ◽  
Zhne Chen ◽  
Jun Du ◽  
Yuyang He ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Energy Density ◽  
Negative Impact ◽  
Laser Energy ◽  
Melting Process ◽  
Laser Energy Density ◽  
Granular System ◽  
Laser Melting ◽  
Content Type ◽  
Powder Bed

Purpose This paper aims to study numerically the influence of the applied laser energy density and the porosity of the powder bed on the thermal behavior of the melt and the resultant instability of the liquid track. Design/methodology/approach A three-dimensional model was proposed to predict local powder melting process. The model accounts for heat transfer, melting, solidification and evaporation in granular system at particle scale. The proposed model has been proved to be a good approach for the simulation of the laser melting process. Findings The results shows that the applied laser energy density has a significantly influence on the shape of the molten pool and the local thermal properties. The relative low or high input laser energy density has the main negative impact on the stability of the scan track. Decreasing the porosity of the powder bed lowers the heat dissipation in the downward direction, resulting in a shallower melt pool, whereas pushing results in improvement in liquid track quality. Originality/value The randomly packed powder bed is calculated using discrete element method. The powder particle information including particle size distribution and packing density is taken into account in placement of individual particles. The effect of volumetric shrinkage and evaporation is considered in numerical model.

Effects of laser energy density on in situ formation of nano-graphite

2019 ◽  
Vol 48 (5) ◽  
pp. 506004
Author(s):  
刘孝谦 Liu Xiaoqian ◽  
骆 芳 Luo Fang ◽  
杜琳琳 Du Linlin ◽  
陆潇晓 Lu Xiaoxiao
Keyword(s):  
Energy Density ◽  
Laser Energy ◽  
Laser Energy Density ◽  
In Situ Formation
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