scholarly journals ANALYSIS OF CHANGES IN THE PHASE AND STRUCTURAL STATE OF AN ALUMINUM ALLOY 1933 SURFACE LAYER, MELTED BY A PULSED ELECTRON BEAM

2020 ◽  
pp. 33-38
Author(s):  
D.E. Myla ◽  
V.V. Bryukhovetsky ◽  
V.V. Lytvynenko ◽  
V.P. Poyda ◽  
A.V. Poyda ◽  
...  

The structural and phase changes in the surface layer of an aluminum alloy 1933 caused by the action of a relativistic pulsed electron beam are studied. The structural and phase state of this layer is determined by the impact action of the electron beam and by the kinetics of crystallization from the melt under ultrafast cooling. The impact of a pulsed electron beam is accompanied by the formation of a developed surface relief and the appearance of microcracks on it. The structure of the modified layer is nonequilibrium. X-ray diffraction studies and the results of energy dispersive X-ray microanalysis made it possible to determine that magnesium oxide inclusions are present in the remelted layer. MgO inclusions are generally uniformly distributed in the remelted layer. The maximum size of MgO inclusions does not exceed 1 μm. The causes and mechanisms of the formation of magnesium oxide during the action of a pulsed electron beam are discussed.

2021 ◽  
Vol 22 (4) ◽  
pp. 655-663
Author(s):  
V.V. Bryukhovetsky ◽  
V.V. Lytvynenko ◽  
D.E. Myla ◽  
V.A. Bychko ◽  
Yu.F. Lonin ◽  
...  

The paper studies the distinctive features of micro-hardness value changes in the zone of industrial aluminum alloy 1933 and alloy 1380 irradiated by the relativistic electron beam. The surface layer was modified under the relativistic electron beam injected along with the equal energy parameters. However, we have to claim that some physical and technological properties of the irradiated alloys layer came with some differences. The modified layer micro-hardness increased over 30% in 1933 aluminum alloy and decreased by 10% in 1380 aluminum alloy. The mechanisms affecting the metal material strengthening transformation after a pulsed electron beam application are analyzed. Thus it was established that one of the core impacts to increase the micro-hardness of 1933 aluminum alloy surface layer was fine MgO impurities being absent in the initial alloy and caused by the irradiation, whilst the micro-hardness of the irradiated layer of the 1380 aluminum alloy decreases due to the dissolution during irradiation of the strengthening phases, which were identified in the initial state.


MRS Advances ◽  
2016 ◽  
Vol 1 (6) ◽  
pp. 433-439 ◽  
Author(s):  
Asghar Ali ◽  
Patrick Morrow ◽  
Redhouane Henda ◽  
Ragnar Fagerberg

AbstractThis study reports on the preparation of cobalt doped zinc oxide (Co:ZnO) films via pulsed electron beam ablation (PEBA) from a single target containing 20 w% Co on sapphire (0001) and silicon (100) substrates. The films have been deposited at various temperatures (350оC, 400оC, 450оC) and pulse frequencies (2 Hz, 4 Hz), under a background argon (Ar) pressure of about 3 mtorr, and an accelerating voltage of 14 kV. The surface morphology has been examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM). According to SEM analysis, the films consist of nano-globules whose size is in the range of 80-178 nm. Energy dispersive x-ray spectroscopy (EDX) reveals that deposition is congruent and the prepared films contain ∼20±5 w% cobalt. It has been found that the nano-globules in the deposited films are cobalt-rich zones containing ∼70 w% Co. From x-ray photoelectron spectroscopy (XPS) analysis, Co 2p3/2 peaks indicate that the deposited films contain CoO (binding energy = 780.5 eV) as well as metallic Co (binding energy = 778.1-778.5 eV). X-ray diffraction (XRD) analysis supports the presence of metallic Co hcp phase (2ϴ = 44.47° and 47.43°) in the films.


2010 ◽  
Vol 154-155 ◽  
pp. 1170-1177
Author(s):  
Yuan Fang Chen ◽  
Xiao Dong Peng ◽  
Jian Jun Hu ◽  
Hong Bin Xu ◽  
Chan Hao

Surface modification of 40Cr steel by high current pulsed electron beam has been investigated . The pulsed times of HCPEB was changed from 1 to 25 to prepare different specimens. Surface microstructures and section microstructures after HCPEB irradiation were detected by using metallurgical microscope, SEM and X-ray diffractometer. It is shown that crater defects were found on the surface after the irradiation of HCPEB and the density of craters will decrease with increasing pulses times. When treated by 27Kev accelerating voltage, with increasing pulse times, the particles located in surface layer were obviously refined .The surface roughness, hardness, wear properties and corrosion resistance were analyzed after irradiation of HCPEB. The wear resistance and corrosion resistance were obviously enhanced after 10 pulses treatment.


1984 ◽  
Vol 35 ◽  
Author(s):  
M.S. Doghmane ◽  
D. Barbier ◽  
A. Laugier

ABSTRACTAu/Si Schottky contacts have been used as test structures to investigate defects induced in virgin C.Z (100) N-type silicon after irradiation with a 12 to 20 KeV mean energy electron beam pulse. A thin and highly damaged surface layer was observed from a fluence threshold of 1 J/cm2. In addition electron traps were detected in the PEBA induced melting layer with concentrations in the 1012-1013 cm-3 range. Their depth profiles have been related to the PEBA induced melting layer thickness. Quenching of multidefect complexes is the most probable mechanism for electron trap generation in the processed layer.


Author(s):  
Yu. F. Ivanov ◽  
O. L. Khasanov ◽  
M. S. Petyukevich ◽  
V. V. Polisadova ◽  
Z. G. Bikbaeva ◽  
...  

The elemental constituents, phase composition and substructural evolution were investigated in the article in the silicon carbide ceramics surface layer which was subjected to the intense pulsed electron beam the density of the electron beam being varied. It was shown that the ceramic layer surface's structure and phase conditions were controlled by the electron beam characteristics. The SiC-ceramics surface layer nanostructuring was detected and the electron beam treatment conditions which lead to this effect were defined.


2016 ◽  
Vol 35 (7) ◽  
pp. 715-721
Author(s):  
Jike Lyu ◽  
Bo Gao ◽  
Liang Hu ◽  
Shuaidan Lu ◽  
Ganfeng Tu

AbstractIn this paper, the effects of high current pulsed electron beam (HCPEB) on the microstructure evolution of casting HPb59-1 (Cu 57.1 mass%, Pb 1.7 mass% and Zn balance) alloy were investigated. The results showed a “wavy” surface which was formed with Pb element existing in the forms of stacking block and microparticles on the top surface layer after treatment. Nanocrystalline structures including Pb grains and two phases (α and β) were formed on the top remelted layer and their sizes were all less than 100 nm. The disordered β phase was generated in the surface layer after HCPEB treatment, which is beneficial for the improvement of surface properties. Meanwhile, there was a large residual stress on the alloy surface, along with the appearance of microcracks, and the preferred orientations of grains also changed.


1996 ◽  
Vol 427 ◽  
Author(s):  
A. E Bair ◽  
T. L. Alford ◽  
Z. Atzmon ◽  
S. D. Marcus ◽  
D. C. Doller ◽  
...  

AbstractShallow contact metallization of SiGeC was studied in anticipation of this alloys use in low power applications. It has been shown that in the solid state reaction of Co on (100) Si, that Co is the moving species with proper annealing conditions. This prevents the formation of Kirkendal voiding in certain device structures. This work studies the Co and Ti metallization of SiGeC. A bilayer of 44 nm of Co on 7 nm of Ti, were electron beam evaporated onto epitaxially grown Si0.77Ge0.21C0.02. The samples were rapid thermal processed at 600 and 900 °C for up to two minutes in a nitrogen ambient. The analysis techniques used were Rutherford backscattering spectrometry which included the used of the 4.27 MeV 12C(α,α) 12C resonance reaction, glancing angle x-ray diffraction, During annealing at all temperatures, Co diffused through the Ti layer and formed CoSi. This phase was confirmed by x-ray diffraction. The Co displaced the Ti to the surface. At 600 °C, Ge diffused to the surface layer, while at 900 °C it was rejected back into the original SiGeC. The sample annealed at 600 °C was subsequently annealed at 900 °C. The Ge in the surface layer was rejected from the surface layer, diffused across the CoSi and back into the SiGeC.


2005 ◽  
Vol 475-479 ◽  
pp. 3959-3962 ◽  
Author(s):  
Sheng Zhi Hao ◽  
B. Gao ◽  
Ai Min Wu ◽  
Jian Xin Zou ◽  
Ying Qin ◽  
...  

High current pulsed electron beam (HCPEB) is now becoming a promising energetic source for the surface treatment of materials. When the concentrated electron flux transferring its energy into a very thin surface layer within a short pulse time, superfast processes such as heating, melting, evaporation and consequent solidification, as well as dynamic stress field induced by an abrupt thermal distribution in the interactive zone impart surface layer with improved physicochemical and mechanical properties. The present paper reports mainly our experimental research work on this new-style technique. Investigations performed with a variety of constructional materials (aluminum, carbon and mold steel, magnesium alloys) have shown that the most pronounced changes of composition, microstructure and properties occur in the near-surface layers, while the thickness of the modified layer with improved mechanical properties (several hundreds of micrometers) is significantly greater than that of the heat-affected zone due to the propagation of stress wave. The surfaces treated with either simply several pulses of bombardment or complex techniques, such as rapid alloying by HCPEB can exhibit improved mechanical and physicochemical properties to some extent.


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