Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

A model for the composite nanostructure of bone suggested by high-resolution transmission electron microscopy

2003 ◽  
Vol 67 (6) ◽  
pp. 1171-1182 ◽  
Author(s):  
B. A. Cressey ◽  
G. Cressey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Preparation Method ◽  
Ion Beam ◽  
Human Bone ◽  
Specimen Preparation ◽  
Transmission Electron ◽  
Ancient Bone ◽  
Close Analogue

AbstractWe have imaged the spatially-preserved microtexture of biogenic apatite, retained together with its collagen template, in non-demineralized human bone using high-resolution transmission electron microscopy. Using ion-beam thinning, a specimen preparation method generally employed for inorganic minerals rather than for biological materials, we have imaged a composite nanostructure of bone not previously reported, and we propose a model for this nano-architecture that involves a boxconstruction of apatite plates and apatite sheets. This observation provides a new understanding of bone strength at the nanometre scale and suggests how post mortem enhancement of this texture by recrystallization probably accounts for the durability of ancient bone. Modern sheep bone (a close analogue for recently dead human bone) imaged in the same way also shows evidence of this composite architecture.

TEM Characterization of the Microstructure of Hot-Hydrostatically Extruded 93W-4.9Ni-2.1Fe Alloy

2014 ◽  
Vol 490-491 ◽  
pp. 198-202
Author(s):  
Yu Chen ◽  
Yang Yu ◽  
Wen Cong Zhan ◽  
Er De Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Plastic Deformation ◽  
Preparation Method ◽  
Microscopic Analysis ◽  
Tungsten Heavy Alloy ◽  
Specimen Preparation ◽  
Tem Characterization ◽  
Transmission Electron

The microscopic analysis of 93W-4.9Ni-2.1Fe (wt. %) tungsten heavy alloy by hot-hydrostatic extrusion with severe plastic deformation strengthening were experimentally investigated mainly by transmission electron microscopy. Due to the profound differences in hardness of the tungsten particles and the NiFeW matrix a special TEM specimen preparation method had to be employed.It was shown that the microstructure of the as-extruded alloy was characterized by elongated tungsten particles with refinement cellular sub-structures consisting of high-density dislocations embedded in a binding Ni-Fe-W matrix phase with fine dynamically re-crystallized grains.

Specimen Preparation of Thin Crystalline Fibers for Transmission Electron Microscopy

1990 ◽  
Vol 199 ◽  
Author(s):  
Rosemarie Koch ◽  
Ann F. Marshall
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Epoxy Resin ◽  
Cross Sections ◽  
Specimen Preparation ◽  
Thin Glass ◽  
Alternative Method ◽  
Transmission Electron ◽  
Short Piece ◽  
Transmission Electron Microscopy Cross

ABSTRACTA technique was developed to prepare crystalline fibers of less than 1 mm diameter for transmission electron microscopy. Cross sections were made by casting a short piece of the fiber in an epoxy resin, sectioning the block, and laminating the slices against thin glass discs for stability before dimpling. Longitudinal sections were reinforced in a similar manner. TEM tungsten rings were sometimes used as an alternative method to add stability to the longitudinal sections. The technique was especially developed for Bi-Sr-Ca-Cu-O compounds but is also suitable for other materials.

Transmission Electron Microscopy Specimen Preparation Method for Multiphase Porous Functional Ceramics

2013 ◽  
Vol 19 (2) ◽  
pp. 501-505 ◽  
Author(s):  
W. Zhang ◽  
L. Theil Kuhn ◽  
P.S. Jørgensen ◽  
K. Thydén ◽  
J.J. Bentzen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Preparation Method ◽  
Ion Beam ◽  
Solid Oxide ◽  
Electrolysis Cell ◽  
Specimen Preparation ◽  
Alignment Procedure ◽  
Transmission Electron ◽  
Functional Ceramics

AbstractAn optimum method is proposed to prepare thin foil transmission electron microscopy (TEM) lamellae of multiphase porous functional ceramics: prefilling the pore space of these materials with an epoxy resin prior to focused ion beam milling. Several advantages of epoxy impregnation are demonstrated by successful preparation of TEM specimens that maintain the structural integrity of the entire lamella. Feasibility of the TEM alignment procedure is demonstrated, and ideal TEM analyses are illustrated on solid oxide fuel cell and solid oxide electrolysis cell materials. Some potential drawbacks of the TEM specimen preparation method are listed for other samples.

Transmission Electron Microscopy of an Aluminum-Silver-Stainless Steel Solid State Bond

1985 ◽  
Vol 43 ◽  
pp. 172-173
Author(s):  
M. J. Carr ◽  
J. F. Shewbridge ◽  
T. O. Wilford
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Specimen Preparation ◽  
Dimensional Control ◽  
Tem Analysis ◽  
Metal Parts ◽  
Dissimilar Metal ◽  
Transmission Electron ◽  
Short Time

Strong solid state bonds are routinely produced between physical vapor deposited (PVD) silver coatings deposited on sputter cleaned surfaces of two dissimilar metal parts. The low temperature (200°C) and short time (10 min) used in the bonding cycle are advantageous from the standpoint of productivity and dimensional control. These conditions unfortunately produce no microstructural changes at or near the interface that are detectable by optical, SEM, or microprobe examination. Microstructural problems arising at these interfaces could therefore easily go undetected by these techniques. TEM analysis has not been previously applied to this problem because of the difficulty in specimen preparation. The purpose of this paper is to describe our technique for preparing specimens from solid state bonds and to present our initial observations of the microstructural details of such bonds.

Transmission Electron Microscopy (TEM) Specimen Preparation Technique using Focused Ion Beam (FIB): Application to Material Characterization of Chemical Vapor Deposition of Tungsten (W) and Tungsten Silicides (WSix)

1997 ◽  
Author(s):  
K. Doong ◽  
J.-M. Fu ◽  
Y.-C. Huang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Chemical Vapor ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Transmission Electron

Abstract The specimen preparation technique using focused ion beam (FIB) to generate cross-sectional transmission electron microscopy (XTEM) samples of chemical vapor deposition (CVD) of Tungsten-plug (W-plug) and Tungsten Silicides (WSix) was studied. Using the combination method including two axes tilting[l], gas enhanced focused ion beam milling[2] and sacrificial metal coating on both sides of electron transmission membrane[3], it was possible to prepare a sample with minimal thickness (less than 1000 A) to get high spatial resolution in TEM observation. Based on this novel thinning technique, some applications such as XTEM observation of W-plug with different aspect ratio (I - 6), and the grain structure of CVD W-plug and CVD WSix were done. Also the problems and artifacts of XTEM sample preparation of high Z-factor material such as CVD W-plug and CVD WSix were given and the ways to avoid or minimize them were suggested.

A Methodology to Reduce Ion Beam Induced Damage in TEM Specimens Prepared by FIB

2002 ◽  
Author(s):  
Chin Kai Liu ◽  
Chi Jen. Chen ◽  
Jeh Yan.Chiou ◽  
David Su
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Integrated Circuit ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Specimen Preparation ◽  
Tem Analysis ◽  
Sensitive Issue ◽  
Transmission Electron

Abstract Focused ion beam (FIB) has become a useful tool in the Integrated Circuit (IC) industry, It is playing an important role in Failure Analysis (FA), circuit repair and Transmission Electron Microscopy (TEM) specimen preparation. In particular, preparation of TEM samples using FIB has become popular within the last ten years [1]; the progress in this field is well documented. Given the usefulness of FIB, “Artifact” however is a very sensitive issue in TEM inspections. The ability to identify those artifacts in TEM analysis is an important as to understanding the significance of pictures In this paper, we will describe how to measure the damages introduced by FIB sample preparation and introduce a better way to prevent such kind of artifacts.

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