Solidifcation of undercooled melt of Mg-Cu alloy entrapped in its primary phase

1992 ◽  
Vol 11 (18) ◽  
pp. 1260-1262 ◽  
Author(s):  
O. P. Pandey ◽  
S. N. Ojha ◽  
T. R. Anantharaman
Keyword(s):  
Primary Phase ◽  
Cu Alloy ◽  
Undercooled Melt

Nonequilibrium solidification of undercooled melt of Ag-Cu alloy entrained in the primary phase

1994 ◽  
Vol 25 (11) ◽  
pp. 2518-2523 ◽  
Author(s):  
O. P. Pandey ◽  
N. S. Mishra ◽  
C. Ramachandra ◽  
S. Lele ◽  
S. N. Ojha
Keyword(s):  
Primary Phase ◽  
Cu Alloy ◽  
Undercooled Melt ◽  
Nonequilibrium Solidification

Redistribution behavior of constitutional elements at an initial crystallization stage in the Zr65Al7.5Ni10Cu17.5 glassy alloy

2001 ◽  
Vol 16 (1) ◽  
pp. 28-31 ◽  
Author(s):  
J. Saida ◽  
M. Matsushita ◽  
A. Inoue
Keyword(s):  
Glassy Alloy ◽  
Glassy State ◽  
Primary Phase ◽  
Face Centered Cubic ◽  
Low Oxygen ◽  
Transformation Behavior ◽  
Cu Alloy ◽  
Single Face ◽  
Face Centered ◽  
Crystallization Stage

We investigated the transformation behavior from glassy to Zr2Ni phase in the Zr65Al7.5Ni10Cu17.5 glassy alloy with a low oxygen content below 400 ppm mass%. The mostly single face centered cubic Zr2Ni phase precipitated as a primary phase at the initial crystallization stage. The Zr2Ni particles had a cubical morphology in the diameter range of 300 to 500 nm and were in an isolated state for the sample annealed at the temperature near crystallization temperature. A significant redistribution leading to the enrichment of Zr and Ni into the Zr2Ni phase is confirmed. Moreover, it is recognized that Cu and Al are rejected from the Zr2Ni phase. The compositional differences of Zr, Al, Ni, and Cu between the Zr2Ni and remaining glassy phases are in the range of 1.5 to 5 at.%. It is strongly suggested that such a significant redistribution of the constitutional elements restrains the nucleation and growth of crystalline phases. It is one of the important factors for the stabilization of the glassy state in Zr–Al–Ni–Cu alloy.

Phase-Field Micro-Solidification Simulation for Dendrite Growth in Ni-Cu Binary Alloy

2013 ◽  
Vol 830 ◽  
pp. 3-7
Author(s):  
Wei Zhou Hou ◽  
Hong Kui Mao
Keyword(s):  
Phase Field ◽  
Growth Parameters ◽  
Field Method ◽  
Isothermal Solidification ◽  
Dendrite Growth ◽  
Phase Field Method ◽  
Solidification Condition ◽  
Solidification Simulation ◽  
Cu Alloy ◽  
Undercooled Melt

By optimizing the relevant dendrite growth parameters of Ni-Cu alloy undercooling melt, it has studied the effect that the dendrite evolution process of undercooled melt and the degree of undercooling melt have on the dendrite growth of undercooling melt. In the isothermal and non-isothermal solidification condition, relatively accurate result is obtained by applying the phase field method to simulate Ni-Cu alloy. Simulation results show non-isothermal simulation with Neuman boundary condition suit to the actual physical process better.

scholarly journals Simulation of Dendritic Growth in Solidification of Al-Cu Alloy by Applying the Modified Cellular Automaton Model with the Growth Calculation of Nucleus within a Cell

2008 ◽  
Vol 594 ◽  
pp. 22-28 ◽  
Author(s):  
Hsiun Chang Peng ◽  
Long Sun Chao
Keyword(s):  
Cellular Automaton ◽  
Directional Solidification ◽  
Growth Velocity ◽  
Dendritic Growth ◽  
Nucleation Site ◽  
Cellular Automaton Model ◽  
Cu Alloy ◽  
A Cell ◽  
Undercooled Melt ◽  
Dendritic Microstructures

Rather than designated directly as solid if the micromesh (or cell) larger than a nucleus is chosen as the nucleation site, the growth of a nucleus in the cell is considered in the application of the modified cellular automaton model to simulate the evolution of dendritic microstructures in the solidification of Al-Cu alloy. The growth velocity of a nucleus or a dendrite tip is calculated according to the KGT (Kurz-Giovanola-Trivedi) model, which is the function of the undercooling. In this study, the dendritic microstructures, such as the free dendritic growth in an undercooled melt and the dendritic growth in the directional solidification, are simulated with the modified growth algorithm in the nucleation cell. The simulated results for the temporal and final morphologies are shown and are in agreement with the experimental ones.

Effects of Low-Voltage Pulsed Magnetic Field and Pouring Temperature on Solidified Structure of Al-4.5%Cu Alloy

2011 ◽  
Vol 399-401 ◽  
pp. 2139-2143
Author(s):  
Quan Zhou ◽  
Le Ping Chen ◽  
Jian Yin
Keyword(s):  
Magnetic Field ◽  
Grain Size ◽  
Low Voltage ◽  
Structure Refinement ◽  
Primary Phase ◽  
Pulse Voltage ◽  
Pulsed Magnetic Field ◽  
Pouring Temperature ◽  
Cu Alloy ◽  
Spherical Crystals

The solidified structure refinement of Al-4.5%Cu under the action of low-voltage pulsed magnetic field (LVPMF) was investigated in the paper. The influences of different pulse voltage and pouring temperature on solidified structure of Al-4.5%Cu alloy were studied. The results show that solidified structure of Al-4.5%Cu alloy can be refined greatly by LVPMF processing. The dendrite growth is restrained and the microstructure is changed from larger dendrite grains to smaller nondendritic grains, and with certain parameters, the equiaxed, non-dendritic grains are gained in the alloy. With the increase of pulse voltage, grain size of the alloy decreases, and the primary phase degrades from developed dendrites into rose-like or spherical crystals. The decrease of pouring temperature enhances the refinement effect of LVPMF processing. With 150 V pulse magnetic field treatment, grain size of the alloy decreases, primary phase degrades and refines gradually with the decrease of pouring temperature.

Peritectic Reactions and Phase Transformations of Sn-30wt%Cu for High Temperature Pb-Free Soldering Applications

2016 ◽  
Vol 857 ◽  
pp. 58-62 ◽  
Author(s):  
Selena Smith ◽  
Guang Zeng ◽  
Jonathan Read ◽  
Stuart D. McDonald ◽  
Kazuhiro Nogita
Keyword(s):  
Phase Diagram ◽  
High Temperature ◽  
Binary Phase Diagram ◽  
Volume Fraction ◽  
Dendritic Structure ◽  
Primary Phase ◽  
Crack Plane ◽  
Negative Effects ◽  
Cu Content ◽  
Cu Alloy

Extending the use of the Sn-Cu system to high-temperature solders poses additional challenges as the necessary high Cu content is in a region of the binary phase diagram which is dominated by the peritectic reaction and has the intermetallic compound (IMC) Cu3Sn as the primary phase, which is known to have negative effects on soldering properties. Minor additions of nickel (Ni) have been reported to suppress the formation of Cu3Sn in low Cu content Sn-Cu solder alloys though higher Cu content alloys have not been investigated. As such, the objective of this paper was to investigate the effect of more significant concentrations of Ni on the microstructure of a Sn-30wt%Cu alloy. An initial addition of 2wt%Ni greatly reduced the volume fractions of Cu3Sn and the amount of eutectic present whilst significantly increasing the volume fraction of Cu6Sn5; however, further additions of Ni had a less pronounced affect. The Sn-30wt%Cu morphology was changed from a plate-like structure to a dendritic structure by adding Ni, which would improve solder performance by decreasing the possible crack plane length.

Plastic deformation of θ ' in Al-4%Cu alloy

1978 ◽  
Vol 36 (1) ◽  
pp. 576-577
Author(s):  
Shrikant P. Bhat
Keyword(s):  
Deformation Behavior ◽  
Room Temperature ◽  
Electron Microscopic Observation ◽  
Bulk Alloy ◽  
Electron Microscopic ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Orowan Mechanism ◽  
The Subject ◽  
Cyclic Straining

deformation behavior of Al-Cu alloys aged to contain θ ' has been the subject of many investigations (e.g., Ref. 1-5). Since θ ' is strong and hard, dislocations bypass θ ' plates (Orowan mechanism) at low strains. However, at high strains the partially coherent θ ' plates are probably sheared, although the mechanism is complex, depending on the form of deformation. Particularly, the cyclic straining of the bulk alloy is known to produce gross bends and twists of θ '. However, no detailed investigation of the deformation of θ ' has yet been reported; moreover, Calabrese and Laird interpreted the deformation of θ ' as largely being elastic.During an investigation of high temperature cyclic deformation, the detailed electron-microscopic observation revealed that, under reversed straining conditions, θ ' particles are severely distorted--bent and twisted depending on the local matrix constraint. A typical electronmicrograph, showing the twist is shown in Fig. 1. In order to establish whether the deformation is elastic or plastic, a sample from a specimen cycled at room temperature was heated inside the microscope and the results are presented in a series of micrographs (Fig. 2a-e).

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