Orientation relationship between the T structure and the icosahedral quasicrystal in the Zn-Mg-Al alloy system

2016 ◽  
Author(s):  
Kei Nakayama ◽  
Junya Watanabe ◽  
Yasumasa Koyama
Keyword(s):  
Orientation Relationship ◽  
Alloy System ◽  
Icosahedral Quasicrystal ◽  
Al Alloy

scholarly journals Effect of Structural Modification on Corrosion Behavior of Hypo Eutectic Al-Si Alloy

2018 ◽  
Vol 778 ◽  
pp. 16-21
Author(s):  
Muhammad Mansoor ◽  
Muhammad Kamran Yaseen ◽  
Shaheed Khan
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Earth Metal ◽  
Alloy System ◽  
Eutectic Phase ◽  
Al Alloy ◽  
General Corrosion ◽  
Corrosion Properties ◽  
Unmodified Alloy ◽  
Cast Alloys

Al-Si eutectic cast alloys are widely used in aeronautical and automobile industries where significantly high strength, toughness and wear resistance are required. This class of cast alloys exhibit relatively low corrosion resistance in brine environments. The mechanical properties of the alloy system mainly depend upon the shape of Si rich eutectic phase, which mainly has acicular geometry. In present research, the effect of modified microstructure of 12 wt. % Si-Al alloy on corrosion behavior was studied. The needle like Si rich eutectic phase was modified to disperse spherical structure using rare earth metal halides. The corrosion rate and pitting behavior of modified and unmodified alloy were evaluated in 3.5% NaCl solution by general corrosion for calculated time. It was observed that the corrosion rate and pitting tendency of modified alloy had been appreciably reduced as compare to unmodified alloy. The improvement of corrosion properties were the attributes of changed morphology and distribution of Si rich eutectic phase.

The Effect of the Microstructure of Semisolid Al Alloy on its Rheology

2014 ◽  
Vol 490-491 ◽  
pp. 109-112
Author(s):  
De Wen Cao ◽  
Jia Huan Wang ◽  
Yu Qing Sun ◽  
Ke Hua Chen ◽  
Cheng Ming Yu ◽  
...  
Keyword(s):  
Particle Size ◽  
Rheological Behavior ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Alloy System ◽  
The State ◽  
Solid Particles ◽  
Al Alloy ◽  
Agglomerate Size ◽  
The One

In the present work, the effect of the microstructure of AlSi6Mg2 alloy on its macro-rheological behavior of the steady AlSi6Mg2 alloy is investigated. Specifically, the effect of particle size, packing mode and degree of the agglomeration of particles are analyzed. It can be seen that the apparent viscosity decreases with increasing the particle size (d) ifdis between a few μm and 200 μm, while the solid particle size does not affect viscosity except this region. This theoretical prediction is in qualitatively agreement with the experimental data. The trend of the variation of the average agglomerate size with the particle size is the same as the one of viscosity. The packing mode of solid particles in agglomerate is closely related to the solid volume fraction and the characteristics of the alloy system. Subsequently, the state of agglomeration of solid particles which determines the rheology of semisolid AlSi6Mg2 alloy, while the external flow conditions (such as shear rate) influence the viscosity by changing the state of agglomeration. Consequently, the particle size, the packing mode and the average agglomerate size have different effect on the rheological behavior of SSMS.

Formation of icosahedral quasicrystal by crystallization of Zr70(Ni, Cu, Pd)30 amorphous alloys

2001 ◽  
Vol 16 (1) ◽  
pp. 20-23 ◽  
Author(s):  
T. Zhang ◽  
A. Inoue ◽  
M. Matsushita ◽  
J. Saida
Keyword(s):  
Amorphous Alloys ◽  
Volume Fraction ◽  
Alloy System ◽  
Icosahedral Phase ◽  
Icosahedral Quasicrystal ◽  
Maximum Volume Fraction ◽  
Higher Temperature ◽  
Binary Alloy System ◽  
Primary Precipitation ◽  
Precipitation Phase

An icosahedral phase was found to be formed as a primary precipitation phase in the crystallization process of binary Zr70Pd30, ternary Zr70Ni30−xPdx, and Zr70Cu30−xPdx (x = 10 and 20 at.%) and quaternary Zr70Ni10Cu10Pd10 amorphous alloys. The maximum volume fraction of the icosahedral phase was nearly 100% for the 20% Pd alloys and the grain size tended to decrease in the range from 40 to 70 nm with increasing Pd content. No icosahedral phase was formed in the Zr–Ni–Cu alloys without Pd, and hence, the addition of Pd was concluded to be essential for the formation of the icosahedral phase in the Zr-based amorphous alloys. It also was noticed that the icosahedral phase was formed even in the binary Zr70Pd30 amorphous alloy. The icosahedral phase was in a metastable state and changes to equilibrium crystalline phases by annealing in the higher temperature range. The finding of the formation of the icosahedral phase in the binary alloy system allowed us to predict the future appearance of a number of icosahedral base alloys in other alloy systems.

Crystallographic effect of a high magnetic field on a solidified hypoeutectic Zn–Al alloy

2014 ◽  
Vol 47 (2) ◽  
pp. 606-612 ◽  
Author(s):  
Lei Li ◽  
Zongbin Li ◽  
Yudong Zhang ◽  
Claude Esling ◽  
Haitao Liu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Orientation Relationship ◽  
High Magnetic Field ◽  
Resistance Force ◽  
Al Alloy ◽  
Magnetic Field Direction ◽  
Continuous Growth ◽  
Β Phase ◽  
Crystallographic Orientation Relationship ◽  
Orientation Modification

Hypoeutectic Zn–4.45 wt% Al solidified under a high magnetic field was investigated crystallographically. With the field, the primary zinc-rich β phase is distributed homogeneously and orients with thecaxis perpendicular to the magnetic field direction. These results are attributed to the magnetic viscosity resistance force and the magnetocrystalline anisotropy of zinc, respectively. The orientation modification also leads to a preferential alignment of the flat-shaped primary β dendrites. Furthermore, with the field, the eutectic β phase shows an orientation character similar to that of the primary β phase. This arises from its continuous growth with the primary β phase. In addition, a specific crystallographic orientation relationship ({0001}β||{111}α, 〈1\overline 210〉β||〈110〉α) exists in some of the eutectics (between the eutectic zinc-rich β and aluminium-rich α phases). However, this orientation relationship is related to the distribution of primary β dendrites, which originates from the independent nucleation of the pseudo-primary α phase attached to the primary β dendrites.

Processing and microstructure correlations of aluminum alloys for thin-film metallizations

1990 ◽  
Vol 48 (4) ◽  
pp. 972-973
Author(s):  
M. Park ◽  
S. J. Krause ◽  
S. R. Wilson
Keyword(s):  
Thin Film ◽  
Grain Size ◽  
Aluminum Alloys ◽  
Integrated Circuit ◽  
Volume Ratio ◽  
Alloy System ◽  
Metal Corrosion ◽  
Al Alloy ◽  
Alloy Thin Film ◽  
Si Content

Aluminum alloys, such as Al-Cu and Al-Cu-Si are the most extensively used metals for interconnects in integrated circuit. The beneficial effect of the Cu addition is to increase the resistance to electromigration and hillock growth. Si is also often added to minimize the erosion in contact windows and enhance the metal corrosion resistance in the wet photoresist development process. Due to the importance of grain boundary transport in electromigration failure, factors such as grain size and grain size distribution, have an important influence on the failure threshold in conjunction with the level of Cu. In addition, the level of Cu and Si has many detrimental effects, such as microcorrosion caused by the galvanic action of Al2Cu precipitates and the occurrence of Si precipitates, which result in points of high resistance. It is not clear what deposition conditions and what quantities of Cu and Si would lead to the optimum properties, in relation to the grain size and the size and distribution of Al2Cu and Si precipitates. Reductions of Cu and Si content can help to decrease the formation of Al2Cu and Si precipitates, but it is believed that these precipitates are readily formed due to the large surface to volume ratio. In the present study, the specific correlations between processing conditions, the amount of Cu and Si additions, and the microstructure of the Al alloy thin film are evaluated for the development of an improved alloy system.

Precipitation of Stable Icosahedral Quasicrystal Phase in A Mg-Zn-Al Alloy

2021 ◽  
Author(s):  
Alok Singh ◽  
Takanobu Hiroto ◽  
Machiko Ode ◽  
Hiroyuki Takakura ◽  
Karel Tesar ◽  
...  
Keyword(s):  
Icosahedral Quasicrystal ◽  
Al Alloy
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