Effects of Heat Treatment and Background Divalent Cation Impurity on the Growth ofFCenters in Highly Pure KCl Crystals

D. c. electrical conductivity of single crystals of NaClO 3 with varying concentrations of divalent cation impurity are studied. The low-temperature conductivity data are analysed to obtain the association energy between the divalent cation impurity and the cation vacancy. By a suitable analysis developed for the extrinsic and intrinsic overlapping region the formation energy per defect pair has been determined. Almost all the defect parameters are determined by graphical treatment of the conductivity data. Finally these parameters are refined by a least square fit of the conductivity data. The values of the various parameters obtained are: (1) impurity-vacancy association energy E a = 0.22 ± 0.01 eV. (2) jump activation energy of cation vacancy E 1j = 0.46 ± 0.01 eV. (3) pre exponential factor for vacancy mobility μ 01 = 0.004 cm 2 V ‒1 s -1 . (4) jump activation energy of interstitial cation E 2j = 0.85 ± 0.04 eV. (5) pre-exponential factor for interstitial mobility μ 02 = 14.7 cm 2 V ‒1 s ‒1 . (6) formation energy of a Frenkel defect pair E t = 1.98 ± 0.02 eV. (7) entropy of formation of a Frenkel defect pair S t = 3.0 x 10 ‒3 eV K ‒1 .

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SPECIFIC AGGLUTINATION OF TREPONEMA PALLIDUM BY SERA FROM RABBITS AND HUMAN BEINGS WITH TREPONEMAL INFECTIONS

Journal of Experimental Medicine ◽

10.1084/jem.101.4.367 ◽

1955 ◽

Vol 101 (4) ◽

pp. 367-382 ◽

Cited By ~ 21

Author(s):

Paul H. Hardy ◽

E. Ellen Nell

Keyword(s):

Heat Treatment ◽

Divalent Cation ◽

Treponema Pallidum ◽

Chelating Agent ◽

Agglutination Test ◽

Ethylene Diamine ◽

Human Beings ◽

Serological Tests ◽

Human Sera

A method has been described for the preparation of Treponema pallidum suspensions that are suitable for specific agglutination studies and can be stored at 4°C. for months without loss of agglutinability. Such suspensions have been shown to react with two distinct antibodies in the serum of syphilitic animals and man: Wassermann antibody and a specific treponeme agglutinin. It has been demonstrated that the agglutination of treponemes by specific treponeme agglutinin is enhanced by heat treatment or aging of the suspension, and inhibited by a divalent cation, probably Ca++, normally present in serum. This inhibition has been overcome by the use of a chelating agent, ethylene-diamine tetracetate. These findings have been utilized to devise a simple agglutination test for the diagnosis of treponeme infections that is very sensitive and highly specific. This test has been carried out with 430 human sera, and a comparison has been made of the results of the agglutination, treponemal immobilization, and standard serological tests on these sera. The agglutination test appears to have a specificity comparable to the treponemal immobilization test and considerably greater than the standard serological tests.

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The Precipitation of Si in AlCuSi Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070618 ◽

1973 ◽

Vol 31 ◽

pp. 34-35 ◽

Cited By ~ 1

Author(s):

R. M. Anderson

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Heat Treatment ◽

Solid Solution ◽

Integrated Circuit ◽

Copper Film ◽

Solution Concentration ◽

X Ray ◽

Silicon Thin Films ◽

Before And After

Aluminum-copper-silicon thin films have been considered as an interconnection metallurgy for integrated circuit applications. Various schemes have been proposed to incorporate small percent-ages of silicon into films that typically contain two to five percent copper. We undertook a study of the total effect of silicon on the aluminum copper film as revealed by transmission electron microscopy, scanning electron microscopy, x-ray diffraction and ion microprobe techniques as a function of the various deposition methods.X-ray investigations noted a change in solid solution concentration as a function of Si content before and after heat-treatment. The amount of solid solution in the Al increased with heat-treatment for films with ≥2% silicon and decreased for films <2% silicon.

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The influence of heat treatment on the fiber/matrix interface in a SiC-reinforced glassceramic

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100105771 ◽

1988 ◽

Vol 46 ◽

pp. 742-743

Author(s):

E. Bischoff ◽

O. Sbaizero

Keyword(s):

Heat Treatment ◽

Aluminum Silicate ◽

Lithium Aluminum ◽

Interfacial Region ◽

Specimen Preparation ◽

Crack Wake ◽

Pull Out ◽

Annealed Material ◽

Ultrasonic Drilling ◽

Fiber Matrix Interface

Fiber or whisker reinforced ceramics show improved toughness and strength. Bridging by intact fibers in the crack wake and fiber pull-out after failure contribute to the additional toughness. These processes are strongly influenced by the sliding and debonding resistance of the interfacial region. The present study examines the interface in a laminated 0/90 composite consisting of SiC (Nicalon) fibers in a lithium-aluminum-silicate (LAS) glass-ceramic matrix. The material shows systematic changes in sliding resistance upon heat treatment.As-processed samples were annealed in air at 800 °C for 2, 4, 8, 16 and 100 h, and for comparison, in helium at 800 °C for 4 h. TEM specimen preparation of as processed and annealed material was performed with special care by cutting along directions having the fibers normal and parallel to the section plane, ultrasonic drilling, dimpling to 100 pm and final ionthinning. The specimen were lightly coated with Carbon and examined in an analytical TEM operated at 200 kV.

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Strain-induced martensite effects on transgranular carbide precipitation in type 304 stainless steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087331 ◽

1991 ◽

Vol 49 ◽

pp. 604-605

Author(s):

A.H. Advani ◽

L.E. Murr ◽

D. Matlock

Keyword(s):

Heat Treatment ◽

Grain Boundary ◽

Stress Corrosion Cracking ◽

Stainless Steels ◽

Deformation Twin ◽

Austenitic Stainless Steels ◽

Carbide Precipitation ◽

Strain Induced Martensite ◽

Type 304

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.

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Effect of a Complex Heat Treatment on the Structure of 300M Steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098071 ◽

1981 ◽

Vol 39 ◽

pp. 312-313

Author(s):

R. Padmanabhan ◽

W. E. Wood

Keyword(s):

Heat Treatment ◽

Metal Carbides ◽

Austenite Grain Size ◽

300M Steel ◽

Heat Treated ◽

Strain Fracture ◽

Prior Austenite Grain Size ◽

Short Time ◽

Final Tempering ◽

Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

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Crystallization of MgO • Al2 • SiO2 • ZrO2 glasses

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143778 ◽

1986 ◽

Vol 44 ◽

pp. 440-441

Author(s):

M. A. McCoy

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Powder Processing ◽

Glass Composition ◽

Ceramic Powder ◽

Transformation Toughening ◽

Ceramic Powder Processing ◽

Processing Techniques ◽

Ceramic Matrices

Transformation toughening by ZrO2 inclusions in various ceramic matrices has led to improved mechanical properties in these materials. Although the processing of these materials usually involves standard ceramic powder processing techniques, an alternate method of producing ZrO2 particles involves the devtrification of a ZrO2-containing glass. In this study the effects of glass composition (ZrO2 concentration) and heat treatment on the morphology of the crystallization products in a MgO•Al2•SiO2•ZrO2 glass was investigated.

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Microstructural Development in Nb-Ti Multifilamentary Superconductors During Processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117911 ◽

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.

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High-Temperature Instability of A Cr2Nb-Nb(Cr) Microlaminate Composite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164337 ◽

1996 ◽

Vol 54 ◽

pp. 374-375

Author(s):

M. Larsen ◽

R.G. Rowe ◽

D.W. Skelly

Keyword(s):

Heat Treatment ◽

Solid Solution ◽

High Temperature ◽

Elevated Temperatures ◽

Aircraft Engine ◽

Lattice Parameter ◽

Microstructural Stability ◽

Elevated Temperature Strength ◽

Cross Sectional ◽

Bcc Structure

Microlaminate composites consisting of alternating layers of a high temperature intermetallic compound for elevated temperature strength and a ductile refractory metal for toughening may have uses in aircraft engine turbines. Microstructural stability at elevated temperatures is a crucial requirement for these composites. A microlaminate composite consisting of alternating layers of Cr2Nb and Nb(Cr) was produced by vapor phase deposition. The stability of the layers at elevated temperatures was investigated by cross-sectional TEM.The as-deposited composite consists of layers of a Nb(Cr) solid solution with a composition in atomic percent of 91% Nb and 9% Cr. It has a bcc structure with highly elongated grains. Alternating with this Nb(Cr) layer is the Cr2Nb layer. However, this layer has deposited as a fine grain Cr(Nb) solid solution with a metastable bcc structure and a lattice parameter about half way between that of pure Nb and pure Cr. The atomic composition of this layer is 60% Cr and 40% Nb. The interface between the layers in the as-deposited condition appears very flat (figure 1). After a two hour, 1200 °C heat treatment, the metastable Cr(Nb) layer transforms to the Cr2Nb phase with the C15 cubic structure. Grain coarsening occurs in the Nb(Cr) layer and the interface between the layers roughen. The roughening of the interface is a prelude to an instability of the interface at higher heat treatment temperatures with perturbations of the Cr2Nb grains penetrating into the Nb(Cr) layer.

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