Microstructural Development in Neutron Irradiated Zircaloy-4

2009 ◽  
pp. 442-442-15
Author(s):  
WJS Yang
Keyword(s):  
Microstructural Development

Microstructural Development in Nb-Ti Multifilamentary Superconductors During Processing

1985 ◽  
Vol 43 ◽  
pp. 190-191
Author(s):  
A. W. West
Keyword(s):  
Heat Treatment ◽  
Critical Current Density ◽  
Copper Matrix ◽  
Wire Drawing ◽  
Heat Treatments ◽  
Microstructural Development ◽  
Final Size ◽  
Density Values ◽  
The Wire ◽  
Multifilamentary Superconductors

The influence of the filament microstructure on the critical current density values, Jc, of Nb-Ti multifilamentary superconducting composites has been well documented. However the development of these microstructures during composite processing is still under investigation.During manufacture, the multifilamentary composite is given several heat treatments interspersed in the wire-drawing schedule. Typically, these heat treatments are for 5 to 80 hours at temperatures between 523 and 573K. A short heat treatment of approximately 3 hours at 573K is usually given to the wire at final size. Originally this heat treatment was given to soften the copper matrix, but recent work has shown that it can markedly change both the Jc value and microstructure of the composite.

Processing and characterization of YBa2Cu3O7−x/Ag composites

1990 ◽  
Vol 48 (4) ◽  
pp. 46-47
Author(s):  
Jafar Javadpour ◽  
Bradley L. Thiel ◽  
Sarikaya Mehmet ◽  
Ilhan A. Aksay
Keyword(s):  
Composite System ◽  
Precursor Solution ◽  
Microstructural Development ◽  
Superconducting Properties ◽  
Practical Applications ◽  
Nitrate Precursor ◽  
Cold Pressed ◽  
Tape Cast ◽  
Composite Samples

Practical applications of bulk YBa2Cu3O7−x materials have been limited because of their inadequate critical current density (jc) and poor mechanical properties. Several recent reports have indicated that the addition of Ag to the YBa2Cu3O7−x system is beneficial in improving both mechanical and superconducting properties. However, detailed studies concerning the effect of Ag on the microstructural development of the cermet system have been lacking. Here, we present some observations on the microstructural evolution in the YBa2Cu3O7−x/Ag composite system.The composite samples were prepared by mixing various amounts (2.5 - 50 wt%) AgNO3 in the YBa2Cu3O7−x nitrate precursor solution. These solutions were then spray dried and the resulting powders were either cold pressed or tape cast. The microstructures of the sintered samples were analyzed using SEM (Philips 515) and an analytical TEM (Philips 430T).The SEM micrographs of the compacts with 2.5 and 50 wt% Ag addition sintered at 915°C (below the melting point of Ag) for 1 h in air are displayed in Figs. 1 and 2, respectively.

Microstructural control of pitch matrix carbon-carbon composite by iodine treatment

1998 ◽  
Vol 13 (2) ◽  
pp. 302-307 ◽  
Author(s):  
H. Kajiura ◽  
Y. Tanabe ◽  
E. Yasuda ◽  
A. Kaiho ◽  
I. Shiota ◽  
...  
Keyword(s):  
Coal Tar ◽  
Carbon Composite ◽  
Coal Tar Pitch ◽  
Microstructural Development ◽  
Carbon Yield ◽  
Graphitic Structure ◽  
Matrix Microstructure ◽  
Iodine Treatment ◽  
Matrix Precursor ◽  
Microstructural Control

Matrix microstructure of a pitch-based carbon-carbon composite was controlled by an iodine treatment. Coal-tar pitch having the softening point of 101 °C was used as a matrix precursor. The iodine treatment was carried out on a pitch-impregnated specimen at 90 °C for 3–20 h. The specimen was carbonized at 800 °C and graphitized at 2000–3000 °C. The carbon yield increased from 73% to 93% by the iodine treatment. Microstructures of carbonized specimens changed from a flow type texture to a mosaic type one by the iodine treatment. The microstructural development to graphitic structure was suppressed by the iodine treatment.

Review of Phonon Behavior and Microstructural Development Leading to Martensitic Transformations in NixAl(100-x) Alloys

1991 ◽  
Vol 246 ◽  
Author(s):  
L. E. Tanner ◽  
S. M. Shapiro ◽  
D. Schryvers ◽  
Y. Noda
Keyword(s):  
Phonon Mode ◽  
Inelastic Neutron Scattering ◽  
Dynamical Behavior ◽  
Martensitic Transformations ◽  
High Resolution Electron Microscopy ◽  
Inelastic Neutron ◽  
Microstructural Development ◽  
Martensitic Transformation Temperature ◽  
Resolution Electron ◽  
Structural Configurations

AbstractElastic and inelastic neutron-scattering and high-resolution electron-microscopy examinations of the β2 (B2) phase of NixAl(100-x) alloys show a direct relationship between the anomalous changes in lattice dynamical behavior and the evolution of static premartensitic structural configurations as the β2 cools toward its martensitic transformation temperature, Ms. The resulting microstructure is a fine-scale mosaic assembly of nonuniformly distorted and modulated domains, in which {110}<110> shear-plus-shuffle displacements give rise to the {110}B2 micromodulations of ∼1.3 nm wavelength. These displacements are derived from the unusually low energy of the Σ4<ζζ0>–TA2 phonon mode and its anomalous temperaturedependent incomplete softening at ζ = 0 (viz., the elastic constant C) and at ζ ≈ 0.16. These inhomogeneously strained domains (ISDs) are believed to be centered on low strain-amplitude defects. They are viewed as strain embryos of the product 7M(5, 2) martensite but are generally too weak to act as potent nucleation centers. Similar ISD configurations develop at defects with higher strain amplitudes (e.g., dislocations, grain boundaries) and these are the most likely sites for heterogeneous nucleation to occur.

Pathways for microstructural development in TiAl

1988 ◽  
Vol 98 ◽  
pp. 265-268 ◽  
Author(s):  
J.A. Graves ◽  
L.A. Bendersky ◽  
F.S. Biancaniello ◽  
J.H. Perepezko ◽  
W.J. Boettinger
Keyword(s):  
Microstructural Development
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