The electron beam as a heating source

It is impossible to improve the most critical performance properties of machine parts without methods of modifying the surface layer using such concentrated energy as laser, plasma, an electron beam or high-frequency currents. For the rational use of these methods, which are characterized by high heating rates, i.e. about 104 ... 105oC/sec a reliable mechanism for determining the processing modes that ensure the required level of quality characteristics of the hardened surface layer of machine parts, is essential. In this paper, the interrelation between the parameter values of thermal cycles, implemented in the surface layer of steel U8, and the modes of electron beam heating in the atmosphere has been determined.

Download Full-text

Microstructural Analysis of Rapid Solidification and Undercooling in the Al-Ge System

MRS Proceedings ◽

10.1557/proc-28-335 ◽

1983 ◽

Vol 28 ◽

Author(s):

M.J. Kaufman ◽

H.L. Fraser

Keyword(s):

Electron Beam ◽

Rapid Solidification ◽

Local Heating ◽

Microstructural Analysis ◽

Liquid Droplets ◽

Amorphous Films ◽

Phase Selection ◽

Heating Source ◽

Electron Microscopes ◽

Microscope Heating Stage

ABSTRACTSubmicron powders, amorphous films and melt spun ribbons of various Al-Ge alloys have been analyzed to determine the relative roles of undercooling and cooling rate in the production of non-equilibrium structures. All analyses were performed in transmission electron microscopes equipped with energy dispersive x-ray spectrometers. The submicron powders, produced by electro-hydrodynamic atomization, were analyzed in their as-received condition and then annealed and/or melted using the electron beam as a local heating source. Once molten, the liquid droplets were undercooled at different cooling rates by varying the rate of beam obstruction. In this manner, a number of different microstructures were produced. These included metastable crystalline phases and mixed amorphous/crystalline structures. By combining this technique with a microscope heating stage, it was possible to carry out controlled dynamic undercooling experiments and determine phase selection as a function of undercooling and composition. The amorphous films were rapidly heated with the electron beam in the microscope and metastable as well as stable phases were produced. The results of these complementary analyses will be compared and discussed with reference to current models and theories of rapid solidification.

Download Full-text

Analysis of the Thermal Transfers in a VASM Crucible: Electron Beam Melting Experiment and Numerical Simulation

Metals ◽

10.3390/met10091152 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1152

Author(s):

Jérémie Haag ◽

Jonathan Martens ◽

Bernard Dussoubs ◽

Alain Jardy ◽

Jean-Pierre Bellot

Keyword(s):

Electron Beam ◽

Raw Materials ◽

Heat Radiation ◽

Vacuum Arc ◽

Adaptive Meshing ◽

Heating Source ◽

Transient Nature ◽

Melting Cycle ◽

Complex Features ◽

Heat Transfers

A description of the Vacuum Arc Skull Melting (VASM) process is presented showing its particularly complex features because of the mixing of porous raw materials with the dense remelted metal as well as the very high temperature and the highly transient nature of the process. This paper presents a 3D transient mathematical modelling of the heat transport with the aim of bringing a better understanding of the thermal behavior of the material into the crucible during a melting cycle. The model takes into account the heat input provided by the incoming metal thanks to an adaptive meshing, as well as the latent heat of solidification and the radiative heat transfers. An experimental validation of the model is presented where an electron beam heating source mimics the heat effect of the arc thanks to an excellent guidance of the beam over the melt surface. A comparison between the measured and calculated temperatures of a steel load is reported and reveals a satisfactory agreement. With very few adjustments, concerning mainly heat radiation at the top surface of metal into the crucible, the numerical model appears to be an efficient numerical tool to simulate the VASM process at the industrial scale.

Download Full-text

A Plasma Electron Beam Heating Source

Shinku ◽

10.3131/jvsj.10.183 ◽

1967 ◽

Vol 10 (5) ◽

pp. 183-189

Author(s):

Seiichiro KASHU ◽

Shuji NISHINO ◽

Chikara HAYASHI

Keyword(s):

Electron Beam ◽

Plasma Electron ◽

Heating Source ◽

Beam Heating ◽

Electron Beam Heating

Download Full-text

Adapting the Electron Beam from SEM as a Quantitative Heating Source for Nanoscale Thermal Metrology

Nano Letters ◽

10.1021/acs.nanolett.9b04940 ◽

2020 ◽

Vol 20 (5) ◽

pp. 3019-3029

Author(s):

Pengyu Yuan ◽

Jason Y. Wu ◽

D. Frank Ogletree ◽

Jeffrey J. Urban ◽

Chris Dames ◽

...

Keyword(s):

Electron Beam ◽

Heating Source ◽

Thermal Metrology

Download Full-text

Modeling of Micro Electron Beam Welding With Melting and Evaporation

Volume 9: Micro- and Nano-Systems Engineering and Packaging, Parts A and B ◽

10.1115/imece2012-88427 ◽

2012 ◽

Author(s):

Satya S. Gajapath ◽

Sushanta K. Mitra ◽

Patricio F. Mendez

Keyword(s):

Electron Beam ◽

Numerical Analysis ◽

Electron Beam Welding ◽

Electron Beams ◽

Medical Industry ◽

Heating Source ◽

Surface Ablation

Integrating the components at micro and nano levels is becoming a challenge as the demand to scale the devices further down grows, especially in the micro-electronics and medical industry. The current use of microwelding technology using laser and electron beams suffers from a major set back of excessive surface ablation. The present paper proposes using electron beam as a volume heating source to avoid surface ablation and arrives at the conditions to micro-weld successfully through numerical analysis.

Download Full-text

ON IMPROVING THE METHOD OF ELECTRON-BEAM DEPOSITION

Journal of Physics Conference Series ◽

10.1088/1742-6596/2077/1/012017 ◽

2021 ◽

Vol 2077 (1) ◽

pp. 012017

Author(s):

Konstantin A. Rozhkov ◽

Sergey S. Starikov ◽

Stepan V. Varushkin ◽

Dmitry N. Trushnikov ◽

Irina A. Zubko

Keyword(s):

Electron Beam ◽

Heat Source ◽

Defect Formation ◽

Beam Power ◽

Filler Wire ◽

Experimental Conditions ◽

Heating Source ◽

Electron Beam Deposition ◽

Wire Feeding ◽

Beam Deposition

Abstract The paper deals with improvement of the electron-beam additive forming of metal products using a vertically fed filler wire in vacuum with two electron beams as a heating source. We compared the importance of the power of the heat source required for fusing the layers with each other and the calculated power of the heat source required to melt the filler wire and the surface of the product. Within the experimental conditions of the multilayer electron beam deposition using side wire feeding, the electron beam power of 2.4 kW was required to ensure fusion without the defect formation between the layers during the deposition of Ti-6Al-4V titanium alloy. At the same time, approximate calculations of the minimum power of the heat source required to melt the filler wire and the surface of the product showed a level of 730 W.

Download Full-text

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100065079 ◽

1971 ◽

Vol 29 ◽

pp. 204-205

Author(s):

G. G. Shaw

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Aluminum Alloy ◽

Electron Beam ◽

Pure Aluminum ◽

Ion Milling ◽

Transmission Electron ◽

Fiber Matrix ◽

Ion Erosion ◽

Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Download Full-text