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Showing 1 to 20 of 61 for “"Al-Si"”.
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Decagonal quasicrystals in the Al(Si)-Cu-Co alloy system
We have found four different decagonal quasicrystals in the Al65Cu20Co 15 alloy system. They have different periodicities along the tenfold axis, namely, 0.4, 0.8, 1.2 and 1.6nm. This suggests that the decagonal quasicrystal might have a fundamental structure with periodicity of 0.4nm, the other …
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Control of morphology Al-Fe-Si phase in Al-Si-Cu hypoeutectic alloy
<p>Aluminum-Silicon (Al-Si) alloys are one of the most versatile aluminum alloys. Iron is considered one of the most harmful elements in Al-Si diecasting alloy because its presence leads to the precipitation of many AlFeSi intermetallic phases and unacceptable mechanical properties, such as …
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Prehnite at the Atomic Scale: Al/Si Ordering, Hydrogen Environment, and High-Pressure Behavior
The mineral prehnite, Ca2(Al,Fe,Mn)(AlSi3O10)(OH)2, is a layered structure consisting of double-sheets of (Al,Si)O4 and SiO4 tetrahedra alternating with single sheets of AlO4(OH)2 octahedra. To understand the ordering in the structure and differences between various samples of prehnite, …
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An ultrasonic study of impurity-interstitial complexes in electron irradiated Al-Si and Al-Ag
… were performed to probe the structure and annealing behavior of solute self interstitial complexes in electron irradiated (T < 70 K) dilute Al-Ag and Al-Si alloys. In both alloy systems, a similar attenuation peak structure is observed. This peak structure strongly suggests that in both alloys, …
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New approaches to casting hypereutectic Al-Si alloys to achieve simultaneous refinement of primary silicon and modification of eutectic silicon
Hypereutectic Al-Si alloys are of increasing interest for applications that require a combination of light weight and high wear resistance, such as pistons, liner-less engine blocks and pumps. The wear resistance of this class of alloys is due to the presence of hard primary Si particles formed …
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Effects of oxide film, Fe-rich phase, porosity and their interactions on tensile properties of cast Al-Si-Mg alloys
Since mechanical properties of cast Al-Si-Mg alloys are directly influenced by microstructural defects, understanding the characteristics of these defects and any interactions between them is important for improving the properties of castings. This research studied the effect of the most common …
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Characterization and Mechanical Properties of Nanoscale Precipitates in Modified Al-Si-Cu Alloys Using Transmission Electron Microscopy and 3D Atom Probe Tomography.
Among the commercial aluminum alloys, aluminum 319 (Al-7wt%Si-4wt%Cu) type alloys are popularly used in automobile engine parts. These alloys have good casting characteristics and excellent mechanical properties resulting from a suitable heat treatment. To get a high strength in the 319 type …
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Assessment of the effect of grain refinement on the solidification characteristics of Al-Si-Cu eutectic cast alloy using thermal analysis technical (CA-CCTA)
Aluminium (Al-Si-Cu) alloys are widely used in automotive, aerospace, and general engineering industries due to their excellent combination of properties, such as good castability, low coefficient of thermal expansion, and high strength-to-weight ratio. Recently, sustainability and recycling of …
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Development of Niobium Boron grain retainer for aluminium silicon alloys
Aluminium castings with a large grain structure have poor mechanical properties which are primarily due to casting defects as opposed to fine grain structure. The grain refinement practice using chemical addition is well established for wrought alloys, however in the case of casting alloys, the …
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Clustering kinetics in Al-Mg-Si alloys investigated by positron annihilation techniques
… Clusterbildungsprozesse in abgeschrecktem reinem Al, Al-Mg und Al-Si, sowie in reinen oder Cu/Ge-haltigen Al-Mg-Si-Legierungen wurden während der Kaltauslagerung mittels Positronen-Lebensdauer-Spektroskopie, Dopplerverbreiterungs-Spektroskopie sowie Thermoanalyse (DSC) untersucht. In reinem Al, …
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Micromechanistic analysis of fatigue in aluminium silicon casting alloys
Due to increasingly stringent environmental legislation, there is a requirement for lower emissions and greater overall efficiency of light vehicle diesel (LVD) engines. This continues to be achieved through the optimisation of design and careful selection of the materials used in key LVD engine …
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Fluid flow behavior of semi-solid aluminum at high shear rates
The rheological behavior and microstructure of semi-solid aluminum alloys were studied using a novel apparatus, the Drop Forge Viscometer (DFV). The viscometer determines force from the curvature of displacement data allowing calculations of viscosities at shear rates in excess of 1000 s-1. …
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Quenching and tempering effects on Rheo-cast F357 aluminium alloy during Nd: YAG laser welding
Al-Si-Mg casting alloys are being used in automotive applications, aerospace applications and other applications requiring heat-treatable permanent mould castings that combine good weldability with high strength and toughness (ASM). These casting alloys are also known for their excellent …
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Microstructural development, phase stability, and toughening in mullite matrix composites
Mullite matrix composites with partially stabilized zirconia and/or SiC whiskers were fabricated by hot pressing of powders which had been prepared from Al, Si, Zr, and Mg (or Y) alkoxide precursors by a sol-gel process. A series of studies were conducted on microstructural evolution, oxidation …
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Measurement of the Fluorine, Sodium, and Aluminum Fluxes in Cosmic Rays with the AMS Experiment on the International Space Station
Primary nuclei (He, C, O, Ne, Mg, Si, ...) are thought to be mainly produced and accelerated in astrophysical sources such as the supernova. Secondary nuclei (Li, Be, B, ...) are mostly produced by interactions of primary nuclei with the interstellar medium. Precise knowledge of the …
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Structural variations of feldspars at high pressure and high temperature
Feldspar minerals are framework aluminosilicates that comprise approximately 60 percent of the Earth's crust. The elastic and thermodynamic properties of this important mineral group are needed for the interpretation of seismic wave velocities, for understanding cation partioning patterns and for …
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Synthesis and crystal chemistry of lanthanide allanites
… chemistry are major obstacles to the crystal chemical characterization of natural allanites. To overcome these problems, allanites, Ca(REE)Fe²+Al₂Si₃O₁₂(OH), where REE = La, La-Ce, Ce, Nd, Sm, Eu, Gd, Er, Dy, Yb and Y have been synthesized hydrothermally from unbuffered and buffered oxide …
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Ferric/ferrous determinations in synthetic biotite
… of formation were examined for two biotite compositions: annite (K₂Fe₅Al₄Si₅O₂₀(OH)₄) and siderophyllite (K₂Fe₆Al₂Si₆O₂₀(OH)₄). The synthesized phases were annealed at fixed hydrogen fugacities using both the solid oxygen buffering technique of Eugster (1957) and the H₂ buffering technique of …
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Electronic structure and optical properties of layered ternary transition-metal carbides and nitrides
The electronic structure and optical properties of Ti3AC2 (A=Al, Si, Ge), Ti2AC (A=Al, Ga, In; Si, Ge, Sn; P, As; S), Ti2AlN, M2AlC (M=V, Nb, Cr) and Tan+1AlCn (n=1~4) have been studied using first-principles orthogonalized linear combination of atomic orbitals (OLCAO) method. These layered ternary …
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