Dislocation Structure of Nickel Powder and its Role in the Sintering Process

1987 ◽  
pp. 59-65 ◽  
Author(s):  
I. P. Arsentyeva ◽  
M. M. Ristić
Keyword(s):  
Dislocation Structure ◽  
Nickel Powder ◽  
Sintering Process

Activated basket anodes from nickel powder Part II: Fabrication of anodes by a liquid phase sintering process

1992 ◽  
Vol 22 (1) ◽  
pp. 8-15 ◽  
Author(s):  
I. J. Bear ◽  
R. C. Flann ◽  
K. J. McDonald ◽  
L. J. Rogers ◽  
R. Woods
Keyword(s):  
Liquid Phase ◽  
Nickel Powder ◽  
Liquid Phase Sintering ◽  
Sintering Process ◽  
Powder Part

A Study of Different Sintering Routes on Properties of Ni-Al2O3 Hydrogen Separation Membrane

2010 ◽  
Vol 434-435 ◽  
pp. 514-517
Author(s):  
Supawan Vichaphund ◽  
Duangduen Atong
Keyword(s):  
Mechanical Properties ◽  
Ball Milling ◽  
Nickel Powder ◽  
Physical And Mechanical Properties ◽  
Hydrogen Separation ◽  
Alumina Powder ◽  
Sintering Process ◽  
Separation Membrane ◽  
Sintering Conditions ◽  
Hydrogen Separation Membrane

This work aimed to investigate the effect of different sintering routes on properties of Ni-Al2O3 membrane. Alumina powder was mixed with 10 wt% nickel powder by dried ball-milling. Then, the mixture powder was uniaxially pressed to a bar shape and sintered via different sintering conditions. First route, the Ni-Al2O3 specimen was sintered at 1300°C for 2 h under air and then reduced at 900°C for 2 h under H2 atmosphere. Second route, the specimen was sintered at 1300°C for 2 h under argon. After sintering process, the physical and mechanical properties of membrane obtained from two routes were compared and discussed.

The dislocation structure of a 10° [110] tilt boundary in silicon

1983 ◽  
Vol 41 ◽  
pp. 114-115
Author(s):  
B. Cunningham ◽  
D.G. Ast
Keyword(s):  
Dislocation Structure ◽  
Tilt Angle ◽  
Imaging Technique ◽  
Diamond Lattice ◽  
Tilt Boundary ◽  
Formation Mechanisms ◽  
Diffraction Contrast ◽  
Lattice Fringe ◽  
Tilt Boundaries ◽  
Chemically Vapor Deposited

There have Been a number of studies of low-angle, θ < 4°, [10] tilt boundaries in the diamond lattice. Dislocations with Burgers vectors a/2<110>, a/2<112>, a<111> and a<001> have been reported in melt-grown bicrystals of germanium, and dislocations with Burgers vectors a<001> and a/2<112> have been reported in hot-pressed bicrystals of silicon. Most of the dislocations were found to be dissociated, the dissociation widths being dependent on the tilt angle. Possible dissociation schemes and formation mechanisms for the a<001> and a<111> dislocations from the interaction of lattice dislocations have recently been given.The present study reports on the dislocation structure of a 10° [10] tilt boundary in chemically vapor deposited silicon. The dislocations in the boundary were spaced about 1-3nm apart, making them difficult to resolve by conventional diffraction contrast techniques. The dislocation structure was therefore studied by the lattice-fringe imaging technique.

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.

Observations of dislocation interactions with recrystallized grain boundaries

1988 ◽  
Vol 46 ◽  
pp. 628-629
Author(s):  
C. W. Price
Keyword(s):  
Dislocation Density ◽  
Grain Boundary ◽  
Strain Rate ◽  
Grain Boundaries ◽  
Dislocation Structure ◽  
Hot Deformation ◽  
Static Recrystallization ◽  
High Dislocation Density ◽  
High Angle ◽  
Dislocation Interactions

Little evidence exists on the interaction of individual dislocations with recrystallized grain boundaries, primarily because of the severely overlapping contrast of the high dislocation density usually present during recrystallization. Interesting evidence of such interaction, Fig. 1, was discovered during examination of some old work on the hot deformation of Al-4.64 Cu. The specimen was deformed in a programmable thermomechanical instrument at 527 C and a strain rate of 25 cm/cm/s to a strain of 0.7. Static recrystallization occurred during a post anneal of 23 s also at 527 C. The figure shows evidence of dissociation of a subboundary at an intersection with a recrystallized high-angle grain boundary. At least one set of dislocations appears to be out of contrast in Fig. 1, and a grainboundary precipitate also is visible. Unfortunately, only subgrain sizes were of interest at the time the micrograph was recorded, and no attempt was made to analyze the dislocation structure.

Bright field and weak-beam images of dislocations gliding on (001) planes in F.C.C. metals

1978 ◽  
Vol 36 (1) ◽  
pp. 352-353
Author(s):  
H. P. Karnthaler ◽  
A. Korner
Keyword(s):  
Single Crystals ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Stage Ii ◽  
Bright Field ◽  
Weak Beam ◽  
Standard Orientation

In f.c.c. metals slip is observed to occur generally on {111} planes. Glide dislocations on intersecting {111} planes can react with each other and form Lomer-Cottrell locks which lie along a <110> direction and are sessile since they are split on two {111} planes. Cottrell already pointed out that these dislocations could glide on {001} planes if they were not split. The first study of this phenomenon has been published recently. It is the purpose of this paper to report some interesting new details of the dislocations gliding on {001} planes in pure Ni, Cu, and Ag deformed at room temperature.Single crystals are grown with standard orientation and strained into stage II. The crystals are sliced parallel to the (001) planes. The dislocation structure is studied by TEM and the Burgers vectors ḇ and glide planes of the dislocations are determined unambiguously.In Fig.l primary P and secondary S dislocations react and form composite dislocations K.

Microstructural Study of Diamond Deformed Under High Pressure and Temperature

1985 ◽  
Vol 43 ◽  
pp. 230-231
Author(s):  
E. F. Koch
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Lattice Structure ◽  
Diamond Particle ◽  
Polycrystalline Diamond ◽  
Sintering Process ◽  
Ion Milling ◽  
Sintered Compact ◽  
Transmission Electron ◽  
High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

The butterfly martensite nucleation in an iron and nickel alloy

1990 ◽  
Vol 48 (4) ◽  
pp. 906-907
Author(s):  
Q.Z. Chen ◽  
X.F. Wu ◽  
T. Ko
Keyword(s):  
Nickel Alloy ◽  
Ethyl Alcohol ◽  
Dislocation Structure ◽  
Martensite Transformation ◽  
Room Temperature ◽  
The Matrix

Some butterfly martensite nuclei were observed in an Fe-27.6Ni-0.89V-0.05C alloy. The alloy was austenitized at 1200°C for 1 hour. Some samples were aged at 850° C for 40 minutes and quenched in 10% brine at room temperature. All the samples were cooled in ethyl alcohol for martensite transformation.A nucleus in an unaged specimen is shown in Fig.1. The nucleus has certain contrast different from the matrix and is shaped like one wing of a butter fly martensite. The SADP of the circled region is measured to be: da=dh, and approximate to dγ(111) and dm(110) with ∠AOB = 55° . It is similar to [011]f.c.c and b patterns in the anglez ∠AOB and the ratio ra/rb, respectively. The SADP shows that the structure of the nucleus is between f.c.c and b.c.c. The dislocation structure within the nucleus is shown in Fig.2. Their Burgers vectors and line directions are also given in it. There are many long dislocations near it without dislocations piled up as shown in Fig.3.Long dislocations are closed at one end as an envelope.

Fabrication and Mechanical Properties of ultra fine WC-6wt.%Co by Spark Plasma Sintering Process

2011 ◽  
Vol 49 (01) ◽  
pp. 40-45 ◽  
Author(s):  
Hyun-Kuk Park ◽  
Seung-Min Lee ◽  
Hee-Jun Youn ◽  
Ki-Sang Bang ◽  
Ik-Hyun Oh
Keyword(s):  
Mechanical Properties ◽  
Spark Plasma Sintering ◽  
Sintering Process ◽  
Plasma Sintering ◽  
Spark Plasma
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