Evolution of textures in zirconium alloys deformed uniaxially at elevated temperatures

1992 ◽  
Vol 23 (1) ◽  
pp. 271-293 ◽  
Author(s):  
A. Salinas Rodríguez ◽  
J. J. Jonas
Keyword(s):  
Elevated Temperatures ◽  
Zirconium Alloys

Preparation of Zirconium Alloys for Ion Bombardment and Transmission Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 88-89
Author(s):  
E. F. Koch ◽  
D. Lee
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Acetic Acid ◽  
Ethylene Glycol ◽  
Glacial Acetic Acid ◽  
Elevated Temperatures ◽  
Zirconium Alloys ◽  
Ion Bombardment ◽  
Sample Holder ◽  
Transmission Electron

A procedure has been developed to reveal ion induced damage in Zircaloy by transmission electron microscopy. The technique consists of using a modified twin-jet electropolishing method to prepare samples for Ni ion bombardment at elevated temperatures followed by further polishing to provide foils suitable for transmission electron microscopy. The electrolyte used to polish Zircaloy-2 consisted of 50 ml perchloric acid (70%), 175 ml glacial acetic acid, and 100 ml ethylene glycol,. A 0.005” thick and 1/8” diameter sample was first polished from one side only, using a E.A. Fischione twin jet electropolisher equipped with a sample holder designed by W.G. Johnston and J.H.Rosolowski, (Fig.1).

scholarly journals Studies on magnetron-sputtered zirconium-silicide coatings deposited on zirconium alloy for the enhancement of their high-temperature oxidation resistance

Nukleonika ◽  
2018 ◽  
Vol 63 (3) ◽  
pp. 73-79 ◽  
Author(s):  
Wojciech Starosta ◽  
Viera K. Semina ◽  
Jerzy Smolik ◽  
Lech Waliś ◽  
Michał Rydzewski ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Zirconium Alloys ◽  
Nuclear Industry ◽  
Air Oxidation ◽  
Temperature Oxidation ◽  
Water Steam ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant ◽  
Oxidation Properties ◽  
Zirconium Silicide

Abstract Zirconium alloys used widely in nuclear industry as fuel claddings are prone to violent oxidation in water steam atmosphere in the case of loss of coolant accident (LOCA). Accompanying generation of large quantities of heat and explosive gaseous hydrogen may lead to destruction of nuclear core. As the safety of nuclear installations is of primary importance, intensive research works are conducted on the development of so-called accident tolerant fuels much less prone to oxidation. In this paper, the application of external zirconium-silicide coatings deposited by magnetron sputtering is proposed. The preliminary results of their synthesis and studies of air oxidation properties at elevated temperatures are presented.

Characterization of Rare-Earth Fluoride Anti-Stokes Phosphors by Scanning arid Transmission Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 142-143
Author(s):  
N. M. P. Low ◽  
L. E. Brosselard
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Elevated Temperatures ◽  
Stoichiometric Composition ◽  
Rare Earth Ions ◽  
Crystalline Solid ◽  
Precipitation Process ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Rare Earth Fluorides

There has been considerable interest over the past several years in materials capable of converting infrared radiation to visible light by means of sequential excitation in two or more steps. Several rare-earth trifluorides (LaF3, YF3, GdF3, and LuF3) containing a small amount of other trivalent rare-earth ions (Yb3+ and Er3+, or Ho3+, or Tm3+) have been found to exhibit such phenomenon. The methods of preparation of these rare-earth fluorides in the crystalline solid form generally involve a co-precipitation process and a subsequent solid state reaction at elevated temperatures. This investigation was undertaken to examine the morphological features of both the precipitated and the thermally treated fluoride powders by both transmission and scanning electron microscopy.Rare-earth oxides of stoichiometric composition were dissolved in nitric acid and the mixed rare-earth fluoride was then coprecipitated out as fine granules by the addition of excess hydrofluoric acid. The precipitated rare-earth fluorides were washed with water, separated from the aqueous solution, and oven-dried.

Observations oh Nucleation and Growth of Voids in Nickel

1970 ◽  
Vol 28 ◽  
pp. 414-415
Author(s):  
J. L. Brimhall ◽  
H. E. Kissinger ◽  
B. Mastel
Keyword(s):  
High Purity ◽  
Growth Stage ◽  
Elevated Temperatures ◽  
Early Growth ◽  
Nucleation And Growth ◽  
Pure Nickel ◽  
Different Temperatures ◽  
Total Fluence ◽  
Neutron Exposure ◽  
Growth Of Voids

Some information on the size and density of voids that develop in several high purity metals and alloys during irradiation with neutrons at elevated temperatures has been reported as a function of irradiation parameters. An area of particular interest is the nucleation and early growth stage of voids. It is the purpose of this paper to describe the microstructure in high purity nickel after irradiation to a very low but constant neutron exposure at three different temperatures.Annealed specimens of 99-997% pure nickel in the form of foils 75μ thick were irradiated in a capsule to a total fluence of 2.2 × 1019 n/cm2 (E > 1.0 MeV). The capsule consisted of three temperature zones maintained by heaters and monitored by thermocouples at 350, 400, and 450°C, respectively. The temperature was automatically dropped to 60°C while the reactor was down.

Voids in Irradiated Tungsten and Molybdenum

1969 ◽  
Vol 27 ◽  
pp. 190-191
Author(s):  
Robert C. Rau ◽  
Robert L. Ladd
Keyword(s):  
Melting Point ◽  
Fast Neutron ◽  
Neutron Irradiation ◽  
Elevated Temperatures ◽  
Irradiation Temperature ◽  
The Body ◽  
Face Centered Cubic ◽  
Body Centered Cubic ◽  
Cubic Metals ◽  
Face Centered

Recent studies have shown the presence of voids in several face-centered cubic metals after neutron irradiation at elevated temperatures. These voids were found when the irradiation temperature was above 0.3 Tm where Tm is the absolute melting point, and were ascribed to the agglomeration of lattice vacancies resulting from fast neutron generated displacement cascades. The present paper reports the existence of similar voids in the body-centered cubic metals tungsten and molybdenum.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

Electron microscopy of crystalline structure in thermotropic random copolymers

1991 ◽  
Vol 49 ◽  
pp. 1054-1055
Author(s):  
Afzana Anwer ◽  
S. Eilidh Bedford ◽  
Richard J. Spontak ◽  
Alan H. Windle
Keyword(s):  
Electron Microscopy ◽  
Crystalline Structure ◽  
Liquid Crystalline ◽  
Elevated Temperatures ◽  
Random Copolymers ◽  
Molecular Characteristics ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Identical Monomer ◽  
Periodic Layer

Random copolyesters composed of wholly aromatic monomers such as p-oxybenzoate (B) and 2,6-oxynaphthoate (N) are known to exhibit liquid crystalline characteristics at elevated temperatures and over a broad composition range. Previous studies employing techniques such as X-ray diffractometry (XRD) and differential scanning calorimetry (DSC) have conclusively proven that these thermotropic copolymers can possess a significant crystalline fraction, depending on molecular characteristics and processing history, despite the fact that the copolymer chains possess random intramolecular sequencing. Consequently, the nature of the crystalline structure that develops when these materials are processed in their mesophases and subsequently annealed has recently received considerable attention. A model that has been consistent with all experimental observations involves the Non-Periodic Layer (NPL) crystallite, which occurs when identical monomer sequences enter into register between adjacent chains. The objective of this work is to employ electron microscopy to identify and characterize these crystallites.

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