The Self-assembled Deposition on the Surface of Mono-crystalline Silicon Induced by High-Current Pulsed Electron Beam

2017 ◽  
Vol 36 (6) ◽  
pp. 593-597
Author(s):  
Zhang Conglin ◽  
Guan Qingfeng ◽  
Chen Jie ◽  
Yan Pengcheng ◽  
Lv Peng
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Crystalline Silicon ◽  
High Current ◽  
Pulsed Electron Beam ◽  
Atomic Force ◽  
Transmission Electron ◽  
Si Nanoparticles ◽  
Surface Microstructures ◽  
Pulsed Irradiation

AbstractHigh-current pulsed electron beam (HCPEB) technique was applied to irradiate the surface of mono-crystalline silicon wafers. Surface microstructures of the irradiated surface were investigated in detail by atomic force microscope (AFM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The experimental results show that HCPEB irradiation with energy density 4 J/cm2 caused evaporation of the irradiated surface. Subsequently, the evaporation Si-droplets was deposited to form Si-nanoparticles on the surface. Meanwhile, the structures of intensive plastic deformation were also introduced within the irradiated surface layer. The dislocation configurations with rectangular and approximate hexagonal network were formed on the surface of Si wafer after 5-pulsed irradiation. The periodic self-deposited structures appear to be related to the configuration of regular dislocations arrays, which were favorable locations for the deposited Si-nanoparticles.

scholarly journals Amorphization and Nano-Crystallization of Ni-Nb Coating on GH3039 Alloys by High Current Pulsed Electron Beam

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 347
Author(s):  
Conglin Zhang ◽  
Xuesu Ji ◽  
Jiahong Wang ◽  
Lingfan Lu ◽  
Zirun Yang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Beam ◽  
Amorphous Layer ◽  
Pulse Number ◽  
Nano Particles ◽  
High Current ◽  
Pulsed Electron Beam ◽  
Transmission Electron ◽  
Pulsed Irradiation

In this paper, the Ni-Nb coatings were successfully prepared onto the GH3039 alloys by High current pulsed electron beam (HCPEB). The transmission electron microscopy (TEM) results confirmed that the Ni-Nb layer of 10-pulsed samples exhibited partial amorphization, which was consisted of γ-Ni particles, rod-like Ni3Nb particles and nano Ni3Nb with 30 nm in size. After 20-pulsed irradiation, the results show that only Ni3Nb clusters with around 3 nm in size were dispersed in fully amorphization layer. With increased pulse number to 30, the nano-particles embedded into the amorphous layer were grown up, the size of which was about 8 nm. The microstructure evolution during HCPEB irradiation was from the partial amorphous to fully amorphous and then to nano-crystallization. The 20-pulsed samples possessed the best hardness and corrosion resistance. The ultrafine clusters uniformly embedded into amorphous layer were main reason for improving properties.

scholarly journals Microstructure Modifications and Associated Corrosion Improvements in GH4169 Superalloy Treated by High Current Pulsed Electron Beam

2015 ◽  
Vol 2015 ◽  
pp. 1-5
Author(s):  
Yichang Su ◽  
Guangyu Li ◽  
Liyuan Niu ◽  
Shengzhi Yang ◽  
Jie Cai ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Optical Microscope ◽  
High Current ◽  
Pulsed Electron Beam ◽  
Density Of Dislocations ◽  
Nickel Based Superalloy ◽  
Transmission Electron ◽  
Gh4169 Superalloy ◽  
Scanning Electron

The surface of the nickel-based superalloy GH4169 was subjected to high-current pulsed electron beam (HCPEB) treatment. The microstructural morphologies of the material were analysed by means of optical microscope (OP), scanning electron microscope (SEM), and transmission electron microscope (TEM). The results reveal that the irradiated surface was remelted and many craters were formed. The density of craters decreased with the increment of HCPEB pulses. After 20-pulsed HCPEB irradiation, nanostructures were formed in the melted region of the surface. Furthermore, slipping bands and high density of dislocations were also formed due to the severe plastic deformation. The selective purification effect, homogenized composition, nanostructures, and dislocation slips introduced by HCPEB irradiation bring a significant improvement of corrosion resistance of GH4169 superalloy.

Influence of Electron Beam Pulsed Times on the Properties of 40Cr

2010 ◽  
Vol 154-155 ◽  
pp. 1170-1177
Author(s):  
Yuan Fang Chen ◽  
Xiao Dong Peng ◽  
Jian Jun Hu ◽  
Hong Bin Xu ◽  
Chan Hao
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
Electron Beam ◽  
High Current ◽  
Wear Properties ◽  
X Ray ◽  
Pulsed Electron Beam ◽  
Surface Microstructures ◽  
40Cr Steel

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.

Nanostructure of 45# Carbon Steel by High Current Pulsed Electron Beam

2009 ◽  
Vol 79-82 ◽  
pp. 317-320
Author(s):  
Hui Zou ◽  
H.R. Jing ◽  
Sheng Zhi Hao ◽  
Chuang Dong
Keyword(s):  
Surface Layer ◽  
Electron Beam ◽  
Electron Microscope ◽  
Carbon Steel ◽  
Short Pulse ◽  
White Layer ◽  
High Current ◽  
Near Surface ◽  
Pulsed Electron Beam ◽  
Modified Surface

When high current pulsed electron beam (HCPEB) transferring its energy into a very thin surface layer within a short pulse time, super fast processes such as heating, melting, evaporation and consequent solidification, as well as dynamic stress induced may impart the surface layer with improved properties. In this paper, HCPEB modification of 45# carbon steel with working parameters of electron energy 25 kV, pulse duration 3.5µs, and energy density 4 J/cm2 was investigated. The microstructures of modified surface were analyzed by scanning electron microscope (SEM) of type JSM 5310 and transmission electron microscope (TEM) of type H-800. It is found that the modified surface layer can be divided into three zones: the white layer or melted layer of depth 3 to10µm, the heat and stress effecting zone 10 µm below and about 250 µm, then matrix, where a nanostructure and/or amorphous layer formed in the near-surface region. It is proved that the whole treatment process is not complex and cost-effective, and has a substantial potential to be applied in industries.

Microstructural Modification of Brush-Plated Nanocrystalline Cr by High Current Pulsed Electron Beam Irradiation

2016 ◽  
Vol 41 ◽  
pp. 87-95 ◽  
Author(s):  
Jian Jun Hu ◽  
Lin Jiang Chai ◽  
Hong Bin Xu ◽  
Chao Ping Ma ◽  
Shu Bin Deng
Keyword(s):  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Thermal Stresses ◽  
Electron Beam Treatment ◽  
High Current ◽  
Beam Irradiation ◽  
Pulsed Electron Beam ◽  
Small Nodule ◽  
Before And After ◽  
Surface Microstructures

Cr layer was fabricated on 40Cr steel by electric brush plating process and then treated by high current pulsed electron beam irradiation technique. Surface microstructures of specimens before and after the irradiation were investigated. Results show that Cr surface is composed of uniformly distributed small nodule units which are composed of fine Cr particles smaller than 100nm. After high current pulsed electron beam treatment, many cracks are found on surface. The main reason is possibly due to the quasi-static thermal stresses accumulated along the surface of the specimens during the electron beam treatment. The surface grain grow from Cr particles because of heating by electron beam, and their size is less than 200nm.

scholarly journals In Situ Observation of Crystalline Silicon Growth from SiO2 at Atomic Scale

Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Kaihao Yu ◽  
Tao Xu ◽  
Xing Wu ◽  
Wen Wang ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Electron Beam ◽  
Crystalline Silicon ◽  
Atomic Scale ◽  
Formation Mechanisms ◽  
In Situ Observation ◽  
Transmission Electron ◽  
Si Nanoparticles ◽  
Speed Up ◽  
Silicon Growth

The growth of crystalline Si (c-Si) via direct electron beam writing shows promise for fabricating Si nanomaterials due to its ultrahigh resolution. However, to increase the writing speed is a major obstacle, due to the lack of systematic experimental explorations of the growth process and mechanisms. This paper reports a systematic experimental investigation of the beam-induced formation of c-Si nanoparticles (NPs) from amorphous SiO2 under a range of doses and temperatures by in situ transmission electron microscopy at the atomic scale. A three-orders-of-magnitude writing speed-up is identified under 80 keV irradiation at 600°C compared with 300 keV irradiation at room temperature. Detailed analysis reveals that the self-organization of c-Si NPs is driven by reduction of c-Si effective free energy under electron irradiation. This study provides new insights into the formation mechanisms of c-Si NPs during direct electron beam writing and suggests methods to improve the writing speed.

scholarly journals Nanocrystalline Cr-Ni Alloying Layer Induced by High-Current Pulsed Electron Beam

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 74 ◽  
Author(s):  
Lingyan Zhang ◽  
Ching-Tun Peng ◽  
Jintong Guan ◽  
Peng Lv ◽  
Qingfeng Guan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Strengthening Mechanism ◽  
High Current ◽  
Nickel Substrate ◽  
X Ray Diffraction ◽  
Pulsed Electron Beam ◽  
Solid Solution Strengthening ◽  
Transmission Electron ◽  
Solution Strengthening

In this investigation, chromium (Cr) was adopted as an alloying element on a nickel substrate, and the alloying process was materialized via high-current pulsed electron beam (HCPEB) irradiation. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were also conducted for microstructure characterization. The results showed that after HCPEB irradiation a nanocrystalline Cr-Ni alloying layer was formed and numerous dislocations were generated, resulting in a great deal of diffusion paths for Cr elements. Moreover, properties including hardness, wear and electrochemical performance were significantly improved after HCPEB irradiation, which was mainly due to the formation of the nanocrystalline Cr–Ni alloying layer. In addition, each strengthening mechanism that contributed to the hardness of the HCPEB-irradiated sample was mathematically analyzed, and solid solution strengthening was found to be of great importance.

scholarly journals Electron-Irradiation-Induced Crystallization of Amorphous Orthophosphates

1996 ◽  
Vol 439 ◽  
Author(s):  
A. Meldrum ◽  
L. A. Boatner ◽  
R. C. Ewing
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Amorphous Matrix ◽  
High Current Density ◽  
High Current ◽  
Transmission Electron ◽  
Oriented Polycrystalline ◽  
Current Densities ◽  
Induced Crystallization ◽  
Inelastic Processes

AbstractAmorphous LaPO4, EuPO4, GdPO4, ScPO4, LuPO4, and fluorapatite [Ca5(PO4)3F] were irradiated by the electron beam in a transmission electron microscope. Irradiations were performed over a range of temperatures from −150 to 300 °C, electron energies from 80 to 200 keV, and current densities from 0.3 to 16 A/cm2. In all cases, the materials crystallized to form a randomly oriented polycrystalline assemblage. Crystallization is driven dominantly by inelastic processes, although ballistic collisions with the target nuclei can become important at energies higher than 175 keV, particularly in apatite. Using a high current density, crystallization is so fast that continuous lines of crystallites can be “drawn” on the amorphous matrix.

Sign in / Sign up

Export Citation Format

Share Document