scholarly journals The Influence of Alloy Composition and microstructure on the corrosion behaviour of Cu-Ni alloys in seawater

1983 ◽  
Vol 34 (4) ◽  
pp. 167-178 ◽  
Author(s):  
L. J. P. Drolenga ◽  
F. P. Ijsseling ◽  
B. H. Kolster
Author(s):  
Matthew R. Libera

The liquid droplets produced by atomization processes are believed to undergo substantial supercooling during solidification, because the catalytic heterogeneities, for statistical reasons, tend to be isolated in the larger droplets. This supercooling can lead to the nucleation of metastable phases. As part of a study on the effect of liquid supercooling on nonequilibrium solidification, three binary Fe-Ni alloys have been produced by conventional argon atomization (Fe-20Ni, Fe-30Ni, and Fe-40Ni). The primary variables in these experiments are: i) the alloy composition; and ii) the powder particle diameter (inversely proportional to supercooling). Of particular interest in this system is the competitive nucleation kinetics between the stable fee and metastable bec phases. Bcc is expected to nucleate preferentially with decreasing %Ni and decreasing particle diameter.


2001 ◽  
Vol 7 (S2) ◽  
pp. 264-265
Author(s):  
H. A. Calderon ◽  
M. Benyoucef ◽  
N. Clement

The excellent mechanical properties of Ni based superalloys depend upon the presence of γ’ particles (LI2 structure). Their volume fraction, spatial distribution and size determine the mechanical strength of these alloys. Ni alloys for technological applications make use of large volume fractions of precipitates where processes of coarsening and coalescence take place during service leading in some cases to deterioration of properties. Addition of different alloying elements prevents accelerated coalescence by retarding diffusion and thus improving the mechanical properties of such alloys. Coalescence can also take place under the influence of an applied stress leading to the formation of rafts of the y' phase. For example the microstructure changes during creep deformation, depending on the alloy composition, with the corresponding formation of dislocation networks and rafts of different morphologies [1]. The γ-γ’ interfaces are also different depending on the alloy composition and most likely to the local distribution of alloying elements and their strain fields.


1990 ◽  
Vol 6 (3) ◽  
pp. 194-198 ◽  
Author(s):  
C. Ringas ◽  
F. P. A. Robinson ◽  
S. B. Luyckx ◽  
J. P. F. Sellschop

2010 ◽  
Vol 649 ◽  
pp. 165-169 ◽  
Author(s):  
Tie Liu ◽  
Qiang Wang ◽  
Zhong Ying Wang ◽  
Dong Gang Li ◽  
Ji Cheng He

The microstructural changes of the primary Al3Ni phases in hypereutectic Al-Ni alloys solidified under various high magnetic field gradients were investigated. It was found that the application of a magnetic field gradient induced an aligned structure of the primary Al3Ni phases similar to those in a high uniform magnetic field. However, the high magnetic field gradient showed more obvious effect on the alignment of the primary Al3Ni phases than the uniform magnetic field, although this effect strongly depended on the alloy composition.


2000 ◽  
Vol 39 (2-4) ◽  
pp. 127-135 ◽  
Author(s):  
J.B. Bajat ◽  
Z. Kačarević-Popović ◽  
V.B. Mišković-Stanković ◽  
M.D. Maksimović

1997 ◽  
Vol 12 (2) ◽  
pp. 434-438 ◽  
Author(s):  
R. M. Stroud ◽  
K. F. Kelton ◽  
S. T. Misture

We present the first high temperature x-ray diffraction (HTXRD) studies of in situ quasicrystal-crystal and crystal-crystal transformations in Ti–Zr–Ni alloys. Together with differential scanning calorimetry studies, these x-ray measurements indicate three separate paths for the Ti–Zr–Ni quasicrystal-crystal transformation: single exothermic, single endothermic, or multiple endothermic. The mode of transformation depends on the alloy composition and the level of environmental oxygen. The crystalline products include the Ti2Ni, MgZn2 Laves, α−(Ti, Zr), and β−(Ti, Zr) phases. In the absence of oxygen, the endothermic transformation of the quasicrystal demonstrates that it is the lowest free energy (stable) phase at the Ti53Zr27Ni20 composition. Oxygen stabilizes the Ti2Ni phase, eliminating both the quasicrystal and the MgZn2 Laves phase, at partial pressures as low as a few hundred ppm.


Sign in / Sign up

Export Citation Format

Share Document