Equilibrium Characteristic at Ordered−Disordered Phase Boundary in Centrifuged Nonequilibrium Colloidal−Crystal System

2004 ◽  
Vol 126 (41) ◽  
pp. 13210-13211 ◽  
Author(s):  
Toshimitsu Kanai ◽  
Tsutomu Sawada ◽  
Junpei Yamanaka ◽  
Kenji Kitamura
Keyword(s):  
Phase Boundary ◽  
Colloidal Crystal ◽  
Crystal System ◽  
Disordered Phase ◽  
Equilibrium Characteristic

scholarly journals Determination of γ′+γ / γ Phase Boundary in Ni-Al-Cr System Using DTA Thermal Analysis

2016 ◽  
Vol 61 (1) ◽  
pp. 237-240 ◽  
Author(s):  
T. Maciąg ◽  
K. Rzyman
Keyword(s):  
Thermal Analysis ◽  
Phase Boundary ◽  
Solution Method ◽  
Intermetallic Phase ◽  
Paper Analysis ◽  
Phase Boundaries ◽  
Disordered Phase ◽  
Dta Analysis ◽  
Cr System

Mechanical properties at elevated temperature, in modern alloys based on intermetallic phase Ni3Al are connected with phase composition, especially with proportion of ordered phase γ′ (L12) and disordered phase γ (A1). In this paper, analysis of one key systems for mentioned alloys - Ni-Al-Cr, is presented. A series of alloys with chemical composition originated from Ni-rich part of Ni-Al-Cr system was prepared. DTA thermal analysis was performed on all samples. Based on shape of obtained curves, characteristic for continuous order-disorder transition, places of course of phase boundaries γ′+γ / γ were determined. Moreover, temperature of melting and freezing of alloys were obtained. Results of DTA analysis concerning phase boundary γ′+γ / γ indicated agreement with results obtained by authors using calorimetric solution method.

Thermophysical Properties of C70 Up to 1 GPa

1994 ◽  
Vol 359 ◽  
Author(s):  
A. Lundin ◽  
A. Soldatov ◽  
B. Sundqvist
Keyword(s):  
Thermal Conductivity ◽  
Bulk Modulus ◽  
Phase Boundary ◽  
Thermophysical Properties ◽  
Molecular Rotation ◽  
Disordered Phase ◽  
Orientational Ordering ◽  
Thermal Conductivity Λ

ABSTRACTWe have measured the thermal conductivity λ and the compressibility of highly pure C70 in the range 90 to 450 K under pressures up to 1.2 GPa. Our results for the thermal conductivity indicate molecular rotation in C70 above 280 K at zero pressure. The phase boundary for the rotationally disordered phase has an approximate slope dT/dp = 75 K GPa−1. The bulk modulus B increases linearly with increasing p above 0.1 GPa, with an extrapolated zero pressure value at 296 K of B(0) = 8.3 GPa. Unexpected anomalies are found in both B and λ near 100 MPa, and we tentatively suggest that orientational ordering is responsible.

scholarly journals DSC Analysis Of Order–Disorder Transition In Ni3Al Based Alloys From Ni-Al-Cr System

2015 ◽  
Vol 60 (3) ◽  
pp. 1871-1876 ◽  
Author(s):  
T. Maciąg ◽  
K. Rzyman ◽  
R. Przeliorz
Keyword(s):  
Thermal Analysis ◽  
Chemical Composition ◽  
Crystal Lattice ◽  
Phase Boundary ◽  
Characteristic Temperature ◽  
Intermetallic Phase ◽  
Dsc Analysis ◽  
Heating And Cooling ◽  
Disordered Phase ◽  
Cr System

AbstractNi-Al-Cr system is significant for industrial alloys based on intermetallic phase Ni3Al, that crystallizes in crystal lattice L12. It is indicated as γ′, contrary to disordered phase γ which occurs with addition of chromium. DSC analysis was performed on alloys of chemical composition from Ni75Al25÷Ni75Cr25 range of Ni-rich part of Ni-Al-Cr system. In addition, few measurements were conducted using DTA method. Based on curves registered, it was possible to identify characteristic temperature during heating and cooling of the sample. It corresponds to existence of phase boundary γ′+γ / γ in examined alloys. Results of thermal analysis were compared with results obtained with other method performed by authors which is solution calorimetric method.

Antiphase Boundaries in Ordered Ni3FE Crystals

1969 ◽  
Vol 27 ◽  
pp. 62-63
Author(s):  
Y. H. Liu
Keyword(s):  
Domain Size ◽  
Antiphase Domain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardening Mechanism ◽  
Superlattice Structure ◽  
Disordered Phase ◽  
Domain Boundaries ◽  
Atomic Scattering ◽  
The Difference

Ordered Ni3Fe crystals possess a LI2 type superlattice similar to the Cu3Au structure. The difference in slip behavior of the superlattice as compared with that of a disordered phase has been well established. Cottrell first postulated that the increase in resistance for slip in the superlattice structure is attributed to the presence of antiphase domain boundaries. Following Cottrell's domain hardening mechanism, numerous workers have proposed other refined models also involving the presence of domain boundaries. Using the anomalous X-ray diffraction technique, Davies and Stoloff have shown that the hardness of the Ni3Fe superlattice varies with the domain size. So far, no direct observation of antiphase domain boundaries in Ni3Fe has been reported. Because the atomic scattering factors of the elements in NijFe are so close, the superlattice reflections are not easily detected. Furthermore, the domain configurations in NioFe are thought to be independent of the crystallographic orientations.

Ordering in Ni4Mo by TEM and APFIM

1987 ◽  
Vol 45 ◽  
pp. 214-215
Author(s):  
E.A. Kenik ◽  
T.A. Zagula ◽  
M.K. Miller ◽  
J. Bentley
Keyword(s):  
Electron Irradiation ◽  
Low Temperatures ◽  
Short Range ◽  
Atom Probe ◽  
Range Order ◽  
Considerable Time ◽  
Probe Field ◽  
Disordered Phase ◽  
Transmission Electron ◽  
Diffraction Patterns

The state of long-range order (LRO) and short-range order (SRO) in Ni4Mo has been a topic of interest for a considerable time (see Brooks et al.). The SRO is often referred to as 1½0 order from the apparent position of the diffuse maxima in diffraction patterns, which differs from the positions of the LRO (D1a) structure. Various studies have shown that a fully disordered state cannot be retained by quenching, as the atomic arrangements responsible for the 1½0 maxima are present at temperatures above the critical ordering temperature for LRO. Over 20 studies have attempted to identify the atomic arrangements associated with this state of order. A variety of models have been proposed, but no consensus has been reached. It has also been shown that 1 MeV electron irradiation at low temperatures (∼100 K) can produce the disordered phase in Ni4Mo. Transmission electron microscopy (TEM), atom probe field ion microscopy (APFIM), and electron irradiation disordering have been applied in the current study to further the understanding of the ordering processes in Ni4Mo.

DIELECTRIC EVIDENCE FOR EXISTENCE OF TWO-LEVEL-SYSTEMS IN CYCLOHEXANOL, A " GLASSY CRYSTAL " SYSTEM

1982 ◽  
Vol 43 (C9) ◽  
pp. C9-525-C9-527
Author(s):  
G. P. Singh ◽  
R. Vacher ◽  
R. Calemczuk
Keyword(s):  
Crystal System ◽  
Two Level Systems
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