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.

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.

Surface Modification of Pure Titanium by High Current Pulsed Electron Beam

2012 ◽  
Vol 560-561 ◽  
pp. 994-999
Author(s):  
Jie Cai ◽  
Ming Zhen Wan ◽  
Yang Zou ◽  
Peng Lv ◽  
Zhi Yong Han ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Modification ◽  
Electron Beam ◽  
Pure Titanium ◽  
Optical Microscope ◽  
Material Surface ◽  
Material Strength ◽  
High Current ◽  
Pulsed Electron Beam ◽  
Transmission Electron

Polycrystalline pure titanium was irradiated by high-current pulsed electron beam (HCPEB). The microstructure changes and material strength were investigated by using microhardness tester, optical microscope, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) technique. The experimental results indicate that many craters are inevitably formed on the irradiated surface. The eruption of the craters makes the material surface cleaned, which can improve the corrosion resistance of materials. Furthermore, martensitic structure, ultra-fine grains and high-density dislocations are formed on the irradiated surface, which increase the hardness of the treated samples. The microhardness of 20-pulsed sample reaches 286Hv, which is 71% higher than the initial sample. Martensitic transformation, grain refinement and dislocation strengthening induced by HCPEB treatment are the dominating mechanism for the improvements of material strength. It is suggested that HCPEB technique is becoming an effective approach to surface modification for pure titanium and titanium alloy.

Organoclay-reinforced polyethersulfone-modified epoxy-based hybrid nanocomposites

2011 ◽  
Vol 23 (7) ◽  
pp. 526-534 ◽  
Author(s):  
Yang Wang ◽  
Boming Zhang ◽  
Jinrui Ye
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Hybrid Nanocomposites ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Modified Epoxy ◽  
Scanning Electron

Hybrid nanocomposites were successfully prepared by the incorporation of polyethersulfone (PES) and organoclay into epoxy resin. They had higher fracture toughness than the prepared PES/epoxy blend and organoclay/epoxy nanocomposites. The microstructures of the hybrid nanocomposites were studied. They were comprised of homogeneous PES/epoxy semi-interpenetrating network (semi-IPN) matrices and organoclay micro-agglomerates made up of tactoid-like regions composed of ordered exfoliated organoclay with various orientations. The former was confirmed with dynamic mechanical analysis, scanning electron microscopy and transmission electron microscopy, while the latter was successfully observed with X-ray diffraction measurements, optical microscope, scanning electron microscope and transmission electron microscope. The improvement of their fracture toughness was due to the synergistic toughening effect of the PES and the organoclay and related to their microstructures.

Surface treatment of DZ4 directionally solidified nickel-based superalloy by high current pulsed electron beam

2008 ◽  
Vol 62 (3) ◽  
pp. 414-417 ◽  
Author(s):  
Shengzhi Hao ◽  
Xiangdong Zhang ◽  
Xianxiu Mei ◽  
Thierry Grosdidier ◽  
Chuang Dong
Keyword(s):  
Electron Beam ◽  
Surface Treatment ◽  
High Current ◽  
Directionally Solidified ◽  
Pulsed Electron Beam ◽  
Nickel Based Superalloy

Energy Filtered Electron Backscattering Images of 10-nm NbC and AIN Precipitates in Steels Computed by Monte Carlo Simulations

1996 ◽  
Vol 54 ◽  
pp. 150-151
Author(s):  
Raynald Gauvin ◽  
Dominique Drouin ◽  
Pierre Hovington
Keyword(s):  
Monte Carlo ◽  
Electron Beam ◽  
Electron Microscope ◽  
Materials Science ◽  
Specimen Preparation ◽  
Backscattered Electrons ◽  
Electron Backscattering ◽  
Transmission Electron ◽  
Properties Of Materials ◽  
Scanning Electron

In modern materials science, it is important to improve the resolution of the Scanning Electron Microscope (SEM) because small phases play a crutial role in the properties of materials. The Transmission Electron Microscope (TEM) is the tool of choice for imaging small phases embedded in a given matrix. However, this technique is expensive and also is slow owing to specimen preparation. In this context, it is important to improve spatial resolution of the SEM.In electron backscattering images, it is well know that the backscattered electrons have an energetic distribution when they escape the specimen.The electrons having loss less energy are those which have travelled less in the specimen and thus escape closer to the electron beam. So, in filtering the energy of the backscattering electron and keeping those which have loss only a small amount of energy to create the image, a significant improvement of the resolution of such images is expected. New detectors are now under development to take advantage of this technique of imaging.

The effect of high-current pulsed electron beam modification on the surface wetting property of polyamide 6

e-Polymers ◽  
2017 ◽  
Vol 17 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Yuan Fang Chen ◽  
Tao Zhang ◽  
Meng Tang ◽  
Ding Xie ◽  
Qian Long ◽  
...  
Keyword(s):  
Electron Beam ◽  
Photoelectron Spectroscopy ◽  
Polyamide 6 ◽  
High Current ◽  
Surface Wetting ◽  
Water Contact ◽  
X Ray ◽  
Pulsed Electron Beam ◽  
Wetting Property ◽  
Scanning Electron

AbstractThis study demonstrates that different modification pulse voltages affect the wetting property of the surface of polyamide 6 (PA6) with a certain regularity. Broadly, the hydrophilic property of PA6’s surface increases with increasing pulsed voltage. Based on scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis, this paper discusses the mechanism by which high current pulsed electron beam (HCPEB) etching modification influences the surface wettability of PA6. Within a certain range below 28 kV, this effect is caused by an increase of in surface roughness due to HCPEB bombardment of the surface. Within a certain range above 28 kV, HCPEB changes the surface morphology, resulting in changes to the wetting property. Furthermore, by using various pulsed voltages to modify the PA6 surface, this study investigated the ability of the Wenzel model to explain changes in the water contact angle and wetting property of PA6’s surface.

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.

Electron Microscopy and X-Ray Microanalysis in Forensic Science

1973 ◽  
Vol 56 (4) ◽  
pp. 930-943
Author(s):  
John L Brown ◽  
James W Johnson
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Chemical Elements ◽  
Optical Microscope ◽  
Forensic Analysis ◽  
Depth Of Focus ◽  
Crystalline Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Abstract The optical microscope has long been an important tool in forensic analysis for the comparison of firearms markings and the examination and identification of other minute bits of evidence. The electron microscope permits the examination of even smaller details and offers analytical capabilities unique to the type of instrument used. The transmission electron microscope can be used to identify very small amounts of crystalline materials through the process of electron diffraction. The scanning electron microscope can frequently supersede the optical microscope because of its superior depth of focus and range of magnification. When it is equipped with an energy dispersive X-ray analyzer, most of the chemical elements in a sample can be determined. Applications of these instruments have provided some interesting and instructive results in forensic analysis.

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