Energy distribution modelling in the weld zone for various electron beam current values in COMSOL Multiphysics

In this paper the new method for determination of luminescent centers concentration are discussed. While the possibility of electron traps determination and definition of its activation energy are suggested. The cathodoluminescent (CL) method was used. The determination of luminescent centers concentration in silicon oxide is based on the measurements of dependences of CL intensity on electron beam current. The presence and energy of activation of electron traps were studied by measurement of rise time and decay of luminescent band during the stationary irradiation of silica by electron beam.

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Metallurgical and Mechanical Research on Dissimilar Electron Beam Welding of AISI 316L and AISI 4340

Advances in Materials Science and Engineering ◽

10.1155/2016/2509734 ◽

2016 ◽

Vol 2016 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

A. R. Sufizadeh ◽

S. A. A. Akbari Mousavi

Keyword(s):

Electron Beam ◽

Electron Beam Welding ◽

Weld Zone ◽

Tensile Tests ◽

Beam Current ◽

Aisi 316L ◽

Cooling Rates ◽

Minimum Width ◽

Optimum Sample ◽

Aisi 4340

Dissimilar electron beam welding of 316L austenitic stainless steel and AISI 4340 low alloy high strength steel has been studied. Studies are focused on effect of beam current on weld geometry, optical and scanning electron microscopy, X-ray diffraction of the weld microstructures, and heat affected zone. The results showed that the increase of beam current led to increasing depths and widths of the welds. The optimum beam current was 2.8 mA which shows full penetration with minimum width. The cooling rates were calculated for optimum sample by measuring secondary dendrite arm space and the results show that high cooling rates lead to austenitic microstructure. Moreover, the metallography result shows the columnar and equiaxed austenitic microstructures in weld zone. A comparison of HAZ widths depicts the wider HAZ in the 316L side. The tensile tests results showed that the optimum sample fractured from base metal in AISI 316L side with the UTS values is much greater than the other samples. Moreover, the fractography study presents the weld cross sections with dimples resembling ductile fracture. The hardness results showed that the increase of the beam current led to the formation of a wide softening zone as HAZ in AISI 4340 side.

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Study on Electron Beam Welding of AZ61 Magnesium Alloy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.34-35.1516 ◽

2010 ◽

Vol 34-35 ◽

pp. 1516-1520

Author(s):

Hong Ye ◽

Han Li Yang ◽

Zhong Lin Yan

Keyword(s):

Electron Beam ◽

Magnesium Alloys ◽

Welding Speed ◽

Electron Beam Welding ◽

Weld Zone ◽

Welding Process ◽

Processing Parameters ◽

Beam Current ◽

Fine Grained ◽

Section Shape

Electron beam welding process of AZ61 with 10mm thickness magnesium alloys was investigated. The influence of processing parameters including focusing current, welding beam current and welding speed was researched. The results show that an ideal weld bead can be formed by choosing processing parameters properly. Focusing current is main parameter that determines cross section shape. The beam current and welding speed are main parameters that determine the weld width and dimensions. The test results for typical welds indicate that the microhardness of the weld zone is better than that of the base meta1. A fine-grained weld region has been observed and no obvious heat-affected zone is found. The fusion zone mainly consists of small α-Mg phase and β-Mg17A112. The small grains and β phases in the joint are believed to play an important role in the increase of the strength of weld for AZ61 magnesium alloys.

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The Corrosion Studies of Electron Beam Welded Nickel Alloy

MATEC Web of Conferences ◽

10.1051/matecconf/201925303005 ◽

2019 ◽

Vol 253 ◽

pp. 03005 ◽

Cited By ~ 1

Author(s):

M. Sroka ◽

E. Jonda ◽

M. Węglowski ◽

S. Błacha

Keyword(s):

Electron Beam ◽

Process Parameters ◽

Microstructural Analysis ◽

Solidification Process ◽

Beam Current ◽

Surface Oxide Layer ◽

Electron Beam Current ◽

Corrosion Properties ◽

Inconel 617 ◽

Potentiodynamic Anodic Polarization

The paper presents the influence of electron - beam (EB) remelting effect on the surface layer electrochemical parameters obtained from potentiodynamic anodic polarization studies and impedance spectroscopy measurements for a set of Inconel 617 electron beam remelted obtained for different process parameters. The correlation between EBW process parameters and characteristic of surface oxide layer properties and resistance to the acidic environment were discussed. The electrochemical studies were supported by microstructural analysis of the remelted zone (RZ), heat affected zone (HAZ), native metal and observed precipitates formed under rapid solidification process. Both electrochemical technics applied to evaluate corrosion properties of remelted Inconel 617 evidenced a strong influence of the electron beam current on the corrosion resistance.

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NUMERICAL ANALYSIS OF LASING DYNAMICS IN VOLUME FREE ELECTRON LASER

Mathematical Modelling and Analysis ◽

10.3846/1392-6292.2008.13.263-274 ◽

2008 ◽

Vol 13 (2) ◽

pp. 263-273

Author(s):

Svetlana Sytova

Keyword(s):

Electron Beam ◽

Free Electron ◽

Free Electron Laser ◽

Initial Conditions ◽

Beam Current ◽

Beam Current Density ◽

Electron Beam Current ◽

Nonlinear Phenomena ◽

Experimental Development ◽

Lasing Dynamics

Nonlinear phenomena originating in volume free electron laser (VFEL) are investigated by methods of mathematical modelling using computer code VOLC. It was demonstrated the possibility of excitation of quasiperiodic oscillations not far from threshold values of electron beam current density and VFEL resonator length. It was investigated sensibility of numerical solution to initial conditions for different VFEL regimes of operation. Parametric maps with respect to electron beam current and detuning from synchronism condition present complicated root to chaos with windows of periodicity in VFEL. Investigation of chaotic lasing dynamics in VFEL is important in the light of experimental development of VFEL in Research Institute for Nuclear Problems.

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Effect on LY12 Aluminum Alloy Welding Joint Microstructure and Properties with Electron Beam Welding Technical Parameters

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.475-476.1275 ◽

2013 ◽

Vol 475-476 ◽

pp. 1275-1279

Author(s):

Qiang Zheng ◽

Cheng Gang Yang ◽

Yu He ◽

He Chen ◽

Ai Wu Yu

Keyword(s):

Aluminum Alloy ◽

Electron Beam ◽

Weld Metal ◽

Heat Affected Zone ◽

Welding Speed ◽

Electron Beam Welding ◽

Beam Current ◽

Electron Beam Current ◽

Micro Hardness ◽

Technical Parameters

LY12 aluminum alloy was welded with vacuum electron beam welding, the effect of welding speed and electron beam current on the weld microstructure and mechanical properties of welding joints were studied, the results were shown that with the increasing of welding speed or decreasing of electron beam current, the grains in weld metal were refined, so the joint strength were increased. When the electron beam current was 18mA, the welding speed was 1000mm/min, the grains of weld metal were the finest, and the tensile strength was 373.2MPa. In addition, the micro-hardness of weld metal was much lower than base metal and heat affected zone, and the heat affected zone had certain softening phenomenon. With the increasing of welding speed or decreasing of electron beam current, the micro-hardness of weld metal was increased respectively.

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Annihilation Behaviors of Athermal ω-Phase Crystals Due to Electron Irradiation

Microscopy and Microanalysis ◽

10.1017/s1431927602000624 ◽

2000 ◽

Vol 6 (4) ◽

pp. 362-367 ◽

Cited By ~ 10

Author(s):

Hajime Matsumoto ◽

Eiichi Sukedai ◽

Hatsujiro Hashimoto

Keyword(s):

Electron Beam ◽

Electron Irradiation ◽

Beam Current ◽

Dark Field ◽

Electron Beam Current ◽

Ω Phase ◽

Observation Methods ◽

Incubation Periods ◽

Beam Currents

AbstractAnnihilation behaviors of athermal ω-phase crystals formed by cooling at 131 K for 10.8 ks under four different electron irradiation conditions of acceleration voltages of 200 kV and 160 kV, and beam currents of approximately 20 pA/cm2 and 5 pA/cm2 were investigated using in situ dark field and HREM observation methods at 131 K. The effect of acceleration voltages on the lifetimes is recognized, i.e., in the case of approximately equal electron beam current, lifetimes at 200 kV become shorter than those at 160 kV. Also, lifetimes depend on the electron beam current at 200 kV, i.e., the higher the beam currents, the shorter the lifetimes become. However, no distinct dependence can be seen at 160 kV. Since annihilations of athermal ω-phase crystals begin after the electron irradiation for a certain period in each condition, which depends on acceleration voltages and beam currents, it is suggested that the annihilation behaviors have incubation periods.

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