Microstructure and strength of Al-sapphire interface by means of the surface activated bonding method

1997 ◽  
Vol 12 (3) ◽  
pp. 852-856 ◽  
Author(s):  
T. Akatsu ◽  
G. Sasaki ◽  
N. Hosoda ◽  
T. Suga
Keyword(s):  
Room Temperature ◽  
Dissimilar Materials ◽  
Tensile Tests ◽  
Beam Irradiation ◽  
Atom Beam ◽  
Sapphire Surface ◽  
Transmission Electron ◽  
Partially Observed ◽  
Fast Atom Beam ◽  
Bonding Method

Sapphire (α–Al2O3) and Al were joined by means of the surface activated bonding (SAB) method in an ultrahigh vacuum at room temperature. Tensile tests have shown that failure occurred not along the interface but inside the Al bulk near the interface. High resolution transmission electron microscopy has revealed the formation of a direct interface between Al and sapphire, indicating the possibility to artificially fabricate an atomically direct interface of dissimilar materials at room temperature. However, an intermediate layer was partially observed, which might be attributed to the effect of fast atom beam irradiation of the sapphire surface.

Coalescence between Au nanoparticles as induced by nanocurvature effect and electron beam athermal activation effect

Nanoscale ◽  
2018 ◽  
Vol 10 (17) ◽  
pp. 7978-7983 ◽  
Author(s):  
Liang Cheng ◽  
Xianfang Zhu ◽  
Jiangbin Su
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Room Temperature ◽  
Electron Beam Irradiation ◽  
Au Nanoparticles ◽  
Beam Irradiation ◽  
Activation Effect ◽  
Transmission Electron

The coalescence of two single-crystalline Au nanoparticles on surface of amorphous SiOxnanowire, as induced by electron beam irradiation, wasin situstudied at room temperature in a transmission electron microscope.

Mechanical Behavior of Contact Aluminum Alloy

2001 ◽  
Vol 695 ◽  
Author(s):  
David T. Read ◽  
Yi-Wen Cheng ◽  
J. David McColskey ◽  
Robert R. Keller
Keyword(s):  
Room Temperature ◽  
Tensile Tests ◽  
Polycrystalline Aluminum ◽  
Aluminum Films ◽  
High Temperature Heat Treatment ◽  
Transmission Electron ◽  
Silicon Transistors ◽  
Temperature Heat ◽  
Temperature Heat Treatment ◽  
Contact Metal

ABSTRACTWe report the results of tensile tests of thin films of Al-0.5 % Cu deposited on bare silicon. This material was subjected to the complete CMOS fabrication process, including a high-temperature heat treatment. Contact metal makes the electrical connection between the metal wiring and the silicon transistors in a chip. Room-temperature values of yield strength, ultimate tensile strength, and elongation were all lower than the corresponding values found previously for pure electron-beam-evaporated aluminum films. The strengths and elongation decreased slightly as the specimen temperature was raised from 25 to 150°C. The slopes of the stress-strain curves from unloading-reloading runs were lower than the accepted Young's modulus of bulk polycrystalline aluminum. The results are interpreted with the help of scanning and transmission electron microscopy.

Microstructure of ZnO shell on Zn nanoparticles

2004 ◽  
Vol 19 (10) ◽  
pp. 3062-3067 ◽  
Author(s):  
Haiping Sun ◽  
Xiaoqing Pan
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
High Resolution ◽  
Room Temperature ◽  
Electron Beam Irradiation ◽  
Beam Irradiation ◽  
Lattice Imaging ◽  
Transmission Electron ◽  
Small Rotation ◽  
Zn Nanoparticles

When exposed to air at room temperature, Zn nanoparticles oxidize gradually to form crystalline ZnO shells with a thickness of a few nanometers. Electron diffraction and high-resolution lattice imaging revealed that the ZnO layer on the Zn {0001} surface is composed of many epitaxial domains with small rotation angles relative to the lattice of the Zn core. The oxidized Zn particle bends when irradiated by the electron beam in a transmission electron microscope. This is due to the increase of internal stress in the ZnO layer as a result of the realignment of adjacent domains under electron beam irradiation. Corrosion of Zn nanoparticles was observed and the scaling and spalling start to occur on the {1010} prismatic faces.

TEM Investigations of Titanium Processed by ECAP Followed by Cold Rolling

2006 ◽  
Vol 503-504 ◽  
pp. 805-810 ◽  
Author(s):  
Bernhard Mingler ◽  
V.V. Stolyarov ◽  
Michael Zehetbauer ◽  
Wolfgang Lacom ◽  
Hans Peter Karnthaler
Keyword(s):  
Cold Rolling ◽  
Room Temperature ◽  
High Strength ◽  
Tensile Tests ◽  
Coarse Grained ◽  
Angular Pressing ◽  
Transmission Electron ◽  
Cp Ti ◽  
Annealing Experiments

Conventional coarse grained (CG) commercial pure (CP) Ti Grade 2 was studied after cold rolling (CR) at room temperature, and after equal channel angular pressing (ECAP) at 450° C followed by CR, by transmission electron microscopy (TEM) methods. CR of the CG material leads to a microstructure showing initially twins with (0112) type and later subgrains separated by lowangle grain boundaries. CR carried out after ECAP yields the fragmentation of fine grains (300 – 800 nm) mostly bounded by high-angle boundaries into elongated subgrains (~ 100 nm). It was shown with in-situ annealing experiments in the TEM that this microstructure is thermally stable up to a temperature of 450° C. Tensile tests showed that the combination of ECAP with CR has the potential to produce at the same time high strength (941 MPa) and high ductility (16.7%).

scholarly journals AA2219 Aluminum Alloy Processed via Multi-Axial Forging in Cryogenic and Ambient Environments

2019 ◽  
Vol 8 (2) ◽  
pp. 1 ◽  
Author(s):  
Amin Azimi ◽  
Gbadebo Moses Owolabi ◽  
Hamid Fallahdoost ◽  
Nikhil Kumar ◽  
Horace Whitworth ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Room Temperature ◽  
Tensile Tests ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Transmission Electron Microscopy Micrographs ◽  
Transmission Electron ◽  
Second Phase Particles ◽  
Aa2219 Aluminum Alloy ◽  
Cryogenic Processing

This paper presents the microstructure and the mechanical behavior of nanocrystalline AA2219 processed by multi axial forging (MAF) at ambient and cryogenic temperatures. The X-ray diffraction pattern and transmission electron microscopy micrographs in the initial microstructure characterization indicate a more effective severe plastic deformation during the cryogenic MAF than the same process conducted at room temperature. MAF at cryogenic temperature results in crystallite size reduction to nanoscales as well as second phase particles breakage to finer particles which are the crucial factors to increasing the mechanical properties of the material. Fractography analysis and tensile tests results show that cryogenic forging does not only increase the mechanical strength and toughness of the alloys significantly, but also improves the ductility of the material in comparison with the conventional forging. In this comparative regard, cryogenic processing provides 44% increase in the tensile strength of the material only after 2 forging cycles when compared to the room temperature process. In addition, further forging process to the next cycles slightly enhances the tensile strength at the expense of ductility due to less ability of the dislocations to accumulate. However, the ductility of the ambient temperature forged samples decreases at a faster rate than that of cryoforged samples.

scholarly journals Microstructure and Mechanical Properties of Al-3 Vol% CNT Nanocomposites Processed by High-Pressure Torsion

2017 ◽  
Vol 62 (2) ◽  
pp. 1109-1112 ◽  
Author(s):  
H. Asgharzadeh ◽  
H.S. Kim
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
High Pressure ◽  
Room Temperature ◽  
High Pressure Torsion ◽  
Tensile Ductility ◽  
Tensile Tests ◽  
Tensile Fracture ◽  
Tensile Fracture Surface ◽  
Transmission Electron

Abstract Al-3 vol% CNT nanocomposites were processed by high-pressure torsion (HPT) at room temperature under the pressure in the range of 2.5-10 GPa for up to 10 turns. Optical microscopy, scanning electron microscopy, and transmission electron microscopy (TEM) were used to investigate the microstructural evolutions upon HPT. Mechanical properties of the HPT-processed disks were studied using tensile tests and microhardness measurements. The results show gradual evolutions in the density, microstructure, and hardness with increasing the number of turns and applied presure. Nanostructured and elongated Al grains with an average grain thickness of ~40 nm perpendicular to the compression axis of HPT and an aspect ratio of ~3 are formed after 10 turns under 6 GPa. Evaluating the mechanical properties of the 10-turn processed Al/CNT nanocomposites indicates a tensile strength of 321 MPa and a hardness of 122 Hv. The tensile fracture surface of the Al/CNT nanocomposite mostly demonstrates a smooth fracture manner with fine dimples resulting in a low tensile ductility of ~1.5%.

A Facile, Green Route - Electron Beam Irradiation to Nanocrystalline Cadmium Selenide at Room Temperature

2011 ◽  
Vol 284-286 ◽  
pp. 697-702
Author(s):  
Zhen Li ◽  
Li Wei Peng ◽  
Fei Gao ◽  
Deng Yu Pan ◽  
Ming Hong Wu
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Electron Beam Irradiation ◽  
Raw Materials ◽  
Cdse Nanoparticles ◽  
Complexing Agent ◽  
Beam Irradiation ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Effects Of Radiation

In this paper, a rapid, facile and green strategy — electron beam irradiation has been developed to prepare CdSe nanoparticles. 10 mA GJ-2-II electronic accelerator was applied as radiation resource. CdSe nanoparticles were synthesized using NH3 as complexing agent by electron beam method in a colloid system, which used Cd(Ac)2 and Na2SeO3 as raw materials. Nanocrystalline CdSe was prepared rapidly at room temperature under atmospheric pressure. The structure and morphology of prepared CdSe nanoparticles were analyzed by X-ray diffraction and transmission electron microscopy. UV–vis spectroscopy (U-3010, Japan Hitachi) and photoluminescence spectroscopy (PL, F-7000, Japan Hitachi) were used to investigate the optical properties of the CdSe nanoparticles. The effects of radiation dose on the formation of CdSe nanocrystallines were discussed. The possible mechanism of the CdSe grain growth by electron beam irradiation method was proposed.

Domain Formation in Synthetic Quartz

1971 ◽  
Vol 29 ◽  
pp. 156-157
Author(s):  
Joseph J. Comer
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Domain Formation ◽  
Synthetic Quartz ◽  
Transmission Electron ◽  
Black Spots ◽  
Diffraction Mode ◽  
Domain Boundaries ◽  
Kikuchi Lines ◽  
Straight Lines

Domains visible by transmission electron microscopy, believed to be Dauphiné inversion twins, were found in some specimens of synthetic quartz heated to 680°C and cooled to room temperature. With the electron beam close to parallel to the [0001] direction the domain boundaries appeared as straight lines normal to <100> and <410> or <510> directions. In the selected area diffraction mode, a shift of the Kikuchi lines was observed when the electron beam was made to traverse the specimen across a boundary. This shift indicates a change in orientation which accounts for the visibility of the domain by diffraction contrast when the specimen is tilted. Upon exposure to a 100 KV electron beam with a flux of 5x 1018 electrons/cm2sec the boundaries are rapidly decorated by radiation damage centers appearing as black spots. Similar crystallographio boundaries were sometimes found in unannealed (0001) quartz damaged by electrons.

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