A Comparison of in- and ex-situ Shear Bands in Metallic Glass by Transmission Electron Microsopy

2021 ◽  
Author(s):  
Harald Rösner ◽  
Christian Kübel ◽  
Stefan Ostendorp ◽  
Gerhard Wilde
Keyword(s):  
Metallic Glass ◽  
Shear Bands ◽  
Ex Situ ◽  
Transmission Electron

Structure of shear bands in Pd40Ni40P20 bulk metallic glass

2009 ◽  
Vol 24 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Y.M. Chen ◽  
T. Ohkubo ◽  
T. Mukai ◽  
K. Hono
Keyword(s):  
Electron Microscopy ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Short Range ◽  
Short Range Order ◽  
Shear Bands ◽  
Distribution Functions ◽  
Uniform Thickness ◽  
Transmission Electron ◽  
Pair Distribution Functions

The atomic structure of shear bands in Pd40Ni40P20 bulk metallic glass has been compared to an undeformed matrix phase using pair distribution functions (PDFs) derived from energy filtered nanobeam electron diffraction. Shear bands do not show any characteristic contrast in transmission electron microscopy (TEM) images when specimens are prepared with uniform thickness. PDFs from a shear band exhibit a slight decrease in the first peak, indicating a slight difference in packing density and short range order compared to the undeformed matrix.

scholarly journals In situ transmission electron microscopy studies of shear bands in a bulk metallic glass based composite

2001 ◽  
Vol 16 (9) ◽  
pp. 2513-2518 ◽  
Author(s):  
E. Pekarskaya ◽  
C. P. Kim ◽  
W. L. Johnson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Crystalline Phase ◽  
Shear Bands ◽  
Quantitative Parameters ◽  
Transmission Electron ◽  
Narrow Bands

In situ straining transmission electron microscopy (TEM) experiments were performed to study the propagation of the shear bands in the Zr56.3Ti13.8Cu6.9Ni5.6Nb5.0Be12.5 bulk metallic glass based composite. Contrast in TEM images produced by shear bands in metallic glass and quantitative parameters of the shear bands were analyzed. It was determined that, at a large amount of shear in the glass, the localization of deformation occurs in the crystalline phase, where formation of dislocations within the narrow bands are observed.

Transmission Electron Microscopy of Epitaxial silicides grown by ultra high vacuum deposition

1989 ◽  
Vol 47 ◽  
pp. 462-463
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Energy Electron ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Transmission Electron

The silicides CoSi2 and NiSi2 are both metallic with the fee flourite structure and lattice constants which are close to silicon (1.2% and 0.6% smaller at room temperature respectively) Consequently epitaxial cobalt and nickel disilicide can be grown on silicon. If these layers are formed by ultra high vacuum (UHV) deposition (also known as molecular beam epitaxy or MBE) their thickness can be controlled to within a few monolayers. Such ultrathin metal/silicon systems have many potential applications: for example electronic devices based on ballistic transport. They also provide a model system to study the properties of heterointerfaces. In this work we will discuss results obtained using in situ and ex situ transmission electron microscopy (TEM).In situ TEM is suited to the study of MBE growth for several reasons. It offers high spatial resolution and the ability to penetrate many monolayers of material. This is in contrast to the techniques which are usually employed for in situ measurements in MBE, for example low energy electron diffraction (LEED) and reflection high energy electron diffraction (RHEED), which are both sensitive to only a few monolayers at the surface.

A New Method of Wafer Level Plan View TEM Sample Preparation by DualBeam

2008 ◽  
Author(s):  
Hyoung H. Kang ◽  
Michael A. Gribelyuk ◽  
Oliver D. Patterson ◽  
Steven B. Herschbein ◽  
Corey Senowitz
Keyword(s):  
Sample Preparation ◽  
Ex Situ ◽  
Wafer Level ◽  
Cross Sectional ◽  
Plan View ◽  
Manufacturing Line ◽  
Transmission Electron ◽  
Thin Lamella ◽  
Preparation Techniques

Abstract Cross-sectional style transmission electron microscopy (TEM) sample preparation techniques by DualBeam (SEM/FIB) systems are widely used in both laboratory and manufacturing lines with either in-situ or ex-situ lift out methods. By contrast, however, the plan view TEM sample has only been prepared in the laboratory environment, and only after breaking the wafer. This paper introduces a novel methodology for in-line, plan view TEM sample preparation at the 300mm wafer level that does not require breaking the wafer. It also presents the benefit of the technique on electrically short defects. The methodology of thin lamella TEM sample preparation for plan view work in two different tool configurations is also presented. The detailed procedure of thin lamella sample preparation is also described. In-line, full wafer plan view (S)TEM provides a quick turn around solution for defect analysis in the manufacturing line.

scholarly journals Dual Electrochemical Treatments to Improve Properties of Ti6Al4V Alloy

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2479
Author(s):  
Stefano Rossi ◽  
Luciana Volgare ◽  
Carine Perrin-Pellegrino ◽  
Carine Chassigneux ◽  
Erick Dousset ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Combined Treatment ◽  
Amorphous Film ◽  
Amorphous Layer ◽  
Good Alternative ◽  
Surface Treatments ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Fluid Environment

Surface treatments are considered as a good alternative to increase biocompatibility and the lifetime of Ti-based alloys used for implants in the human body. The present research reports the comparison of bare and modified Ti6Al4V substrates on hydrophilicity and corrosion resistance properties in body fluid environment at 37 °C. Several surface treatments were conducted separately to obtain either a porous oxide layer using nanostructuration (N) in ethylene glycol containing fluoride solution, or bulk oxide thin films through heat treatment at 450 °C for 3 h (HT), or electrochemical oxidation at 1 V for 3 h (EO), as well as combined treatments (N-HT and N-EO). In-situ X-ray diffraction and ex-situ transmission electron microscopy have shown that heat treatment gave first rise to the formation of a 30 nm thick amorphous layer which crystallized in rutile around 620 °C. Electrochemical oxidations gave rise to a 10 nm thick amorphous film on the top of the surface (EO) or below the amorphous nanotube layer (N-EO). Dual treated samples presented similar results with a more stable behavior for N-EO. Finally, for both corrosion and hydrophilicity points of view, the new combined treatment to get a total amorphous N-EO sample seems to be the best and even better than the partially crystallized N-HT sample.

scholarly journals High density of shear bands in the Vitreloy bulk metallic glass subjected to high-pressure torsion

2021 ◽  
Vol 1008 ◽  
pp. 012031
Author(s):  
Vasily Astanin ◽  
Dmitry Gunderov ◽  
Zhi Qiang Ren ◽  
Ruslan Valiev ◽  
Jing Tao Wang
Keyword(s):  
High Pressure ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
High Pressure Torsion ◽  
Shear Bands ◽  
High Density

Interaction between parallel shear bands in a metallic glass

2021 ◽  
Vol 566 ◽  
pp. 120882
Author(s):  
Karina E. Avila ◽  
Stefan Küchemann ◽  
Herbert M. Urbassek
Keyword(s):  
Metallic Glass ◽  
Shear Bands

scholarly journals Fracture in Bulk Amorphous Alloys

1998 ◽  
Vol 554 ◽  
Author(s):  
J. A. Horton ◽  
J. L. Wright ◽  
J. H. Schneibel
Keyword(s):  
Crack Propagation ◽  
Crack Growth ◽  
Shear Bands ◽  
Bulk Amorphous Alloy ◽  
In Situ Tem ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Crack Tips ◽  
Temperature Fracture

AbstractThe fracture behavior of a Zr-based bulk amorphous alloy, Zr-10 Al-5 Ti-17.9 Cu-14.6Ni (at.%), was examined by transmission electron microscopy (TEM) and x-ray diffraction forany evidence of crystallization preceding crack propagation. No evidence for crystallizationwas found in shear bands in compression specimens or at the fracture surface in tensile specimens.In- situ TEM deformation experiments were performed to more closely examine actualcrack tip regions. During the in-situ deformation experiment, controlled crack growth occurredto the point where the specimen was approximately 20 μm thick at which point uncontrolledcrack growth occurred. No evidence of any crystallization was found at the crack tips or thecrack flanks. Subsequent scanning microscope examination showed that the uncontrolledcrack growth region exhibited ridges and veins that appeared to have resulted from melting. Performing the deformations, both bulk and in-situ TEM, at liquid nitrogen temperatures (LN2) resulted in an increase in the amount of controlled crack growth. The surface roughness of the bulk regions fractured at LN2 temperatures corresponded with the roughness of the crack propagation observed during the in-situ TEM experiment, suggesting that the smooth-appearing room temperature fracture surfaces may also be a result of localized melting.

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