Coherent orientation relationship between an icosahedral phase and a cubicαphase in melt-spun Al-Si-Mn

1986 ◽  
Vol 33 (8) ◽  
pp. 5328-5332 ◽  
Author(s):  
D. C. Koskenmaki ◽  
H. S. Chen ◽  
K. V. Rao
Keyword(s):  
Orientation Relationship ◽  
Icosahedral Phase ◽  
Melt Spun ◽  
Coherent Orientation

scholarly journals Nanocrystalline Icosahedral Phase Formation in Melt Spun Ti-Zr-Ni Alloys

2001 ◽  
Vol 42 (2) ◽  
pp. 372-375 ◽  
Author(s):  
B. S. Murty ◽  
W. T. Kim ◽  
D. H. Kim ◽  
K. Hono
Keyword(s):  
Phase Formation ◽  
Icosahedral Phase ◽  
Ni Alloys ◽  
Melt Spun

The orientation relationship of α-Co precipitates in melt-spun Cu70Co30

1997 ◽  
Vol 32 (5) ◽  
pp. 485-490 ◽  
Author(s):  
X. Song ◽  
S.W. Mahon ◽  
R.F. Cochrane
Keyword(s):  
Orientation Relationship ◽  
Melt Spun ◽  
Relationship Of

A study of the icosahedral phase: Mg32 (Al, Zn)49

1986 ◽  
Vol 1 (2) ◽  
pp. 247-250 ◽  
Author(s):  
G.V.S. Sastry ◽  
P. Ramachandrarao
Keyword(s):  
Single Phase ◽  
Point Group ◽  
Equilibrium Structure ◽  
Icosahedral Phase ◽  
Group Symmetry ◽  
Point Group Symmetry ◽  
Nodular Structure ◽  
Melt Spun ◽  
Diffraction Patterns

Homogeneous single phase Mg32Al19Zn30 was melt spun to form flakes suitable for TEM examination. The nodular structure gave diffraction patterns with 5.3.2 icosahedral point group symmetry. The formation of the icosahedral phase is rationalized in terms of the Mg(AlZn)49 equilibrium structure. This structure is a Frank-Kasper phase. It has previously been established how such icosahedral order can be anticipated in the Frank-Kasper phases.

Stability and Phase Transformations of Icosahedral Phase in a 41.5Zr41.5Ti17Ni Alloy

2000 ◽  
Vol 15 (4) ◽  
pp. 892-897 ◽  
Author(s):  
S. Yi ◽  
D. H. Kim
Keyword(s):  
Phase I ◽  
Phase Transformations ◽  
Phase Stability ◽  
Melt Spinning ◽  
Annealing Treatment ◽  
Icosahedral Phase ◽  
Melt Spun ◽  
Intermediate States ◽  
Melt Spun Ribbons ◽  
Melt Spinning Technique

Phase stability and transformations of the icosahedral phase (I-phase) in a 41.5Zr41.5Ti17Ni alloy were investigated using melt-spun ribbons and arc-melted bulk samples. A perfect I-phase can be formed directly from liquid through the melt-spinning technique. The I-phase formed in the ribbon is thermodynamically stable and transforms to W-phase, a 1/1 rational approximant above 565 °C. Formation of the perfect I-phase during annealing treatment of the arc-melted sample is very sluggish. Various types of approximants exist as intermediate states for the transformation of crystalline phases to a perfect I-phase.

Decomposition of Quasicrystalline Phase in a Rapidly Solidified Ai-Fe-V-Si Alloy

1990 ◽  
Vol 186 ◽  
Author(s):  
W. J. Park ◽  
S. Ahn ◽  
N.J. Kim
Keyword(s):  
Icosahedral Phase ◽  
Quasicrystalline Phase ◽  
Silicide Phase ◽  
In Situ Tem ◽  
Matrix Interface ◽  
Melt Spun ◽  
Wheel Side ◽  
Rapidly Solidified ◽  
Cast Microstructure

AbstractDecomposition of quasicrystalline phase formed in a rapidly solidified Al-Fe-V-Si alloy has been studied by TEM. The as-cast microstructure varies through the thickness of melt-spun ribbon; microeutectic precipitation of the bcc silicide near the wheel side, formation of globular quasicrystalline icosahedral phase with the microeutectic silicide phase at the middle of the ribbon, and the decomposition of quasicrystalline phase near the air side of the ribbon. During heating, as observed by annealing studies and by in-situ TEM studies, quasicrystalline phase decomposes into various phases such as aluminum, silicide and other unidentified phases. It has been shown that the preferential sites for the transformation are either at the center of quasicrystalline particles or at the quasicrystal/matrix interface, depending on the location of quasicrystalline particles.

The coprecipitation of Cr3P and Cr in Cu

1988 ◽  
Vol 46 ◽  
pp. 764-765
Author(s):  
M.J. Witcomb ◽  
U. Dahmen ◽  
K.H. Westmacott
Keyword(s):  
Orientation Relationship ◽  
Interface Structure ◽  
Model System ◽  
Relative Orientation ◽  
Age Hardening ◽  
Precipitation Behavior ◽  
Solution Treated ◽  
Small Needle ◽  
Diffraction Patterns ◽  
Interface Structures

Cu-Cr age-hardening alloys are of interest as a model system for the investigation of fcc/bcc interface structures. Several past studies have investigated the morphology and interface structure of Cr precipitates in a Cu matrix (1-3) and good success has been achieved in understanding the crystallography and strain contrast of small needle-shaped precipitates. The present study investigates the effect of small amounts of phosphorous on the precipitation behavior of Cu-Cr alloys.The same Cu-0.3% Cr alloy as was used in earlier work was rolled to a thickness of 150 μm, solution treated in vacuum at 1050°C for 1h followed by quenching and annealing for various times at 820 and 863°C.Two laths and their corresponding diffraction patterns in an alloy aged 2h at 820°C are shown in correct relative orientation in Fig. 1. To within the limit of accuracy of the diffraction patterns the orientation relationship was that of Kurdjumov-Sachs (KS), i.e. parallel close-packed planes and directions.

Microstructural Variations in Melt-Spun Rapidly Solidified Ribbons

1985 ◽  
Vol 43 ◽  
pp. 54-55
Author(s):  
L. A. Bendersky ◽  
W. J. Boettinger
Keyword(s):  
Solid State ◽  
Processing Parameters ◽  
Heat Extraction ◽  
Solid State Reactions ◽  
Careful Examination ◽  
Ion Milling ◽  
Melt Spun ◽  
Wheel Side ◽  
Rapidly Solidified ◽  
Heat Extraction Rate

Rapid solidification produces a wide variety of sub-micron scale microstructure. Generally, the microstructure depends on the imposed melt undercooling and heat extraction rate. The microstructure can vary strongly not only due to processing parameters changes but also during the process itself, as a result of recalescence. Hence, careful examination of different locations in rapidly solidified products should be performed. Additionally, post-solidification solid-state reactions can alter the microstructure.The objective of the present work is to demonstrate the strong microstructural changes in different regions of melt-spun ribbon for three different alloys. The locations of the analyzed structures were near the wheel side (W) and near the center (C) of the ribbons. The TEM specimens were prepared by selective electropolishing or ion milling.

Sign in / Sign up

Export Citation Format

Share Document