			Home About us Contact

Al Alloy (al + alloy)

Distribution by Scientific Domains

Polymers and Materials Science	85%

Selected Abstracts

Numerical Determination of Heat Distribution and Castability Simulations of as Cast Mg,Al Alloys (Adv. Eng.

ADVANCED ENGINEERING MATERIALS, Issue 3 2009
Mater.
The cover shows the simulated grains for Mg-10%Al, the dendritic, microstructure can be seen. More details can be found in the article of S.S. Khan on page 162. [source]

Numerical Determination of Heat Distribution and Castability Simulations of as Cast Mg,Al Alloys,

ADVANCED ENGINEERING MATERIALS, Issue 3 2009
Shehzad Saleem Khan
Magnesium alloys offer a large potential as lightweight structures especially in the automotive industry. Research and development of magnesium alloys depend largely on the metallurgist's understanding and ability to control the microstructure of the as cast part. This research work comprises the determination of experimental parameters to simulate fluidity and microstructure of magnesium/aluminum binary alloys. [source]

Negative Strain-rate Sensitivity in a Nanostructured Aluminum Alloy,

ADVANCED ENGINEERING MATERIALS, Issue 10 2006
Q. Han
The influence of strain rate in the range of 10,1 to 10,5 s,1 on the compression behavior of a cryomilled 5083 Al alloy is studied. The compression flow stress remains constant after an initial short strain hardening and a small stress dip, which indicates a dynamic saturation of dislocations. It is found that the compression flow stress increases with decreasing strain rate, which is believed to be attributed to dynamic strain aging. [source]

Effects of spectrum modification on fatigue crack growth

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 3 2010
D. KUJAWSKI
ABSTRACT The purpose of this study was to investigate experimentally the effects associated with modification of a loading spectrum recorded from P-3 a maritime aircraft on fatigue crack growth behaviour. The material is 2324-T39 Al alloy widely used in the aircraft industry. Experiments were conducted using the full spectrum and modified versions of it such as only ,positive' (no negative loads) or with reduced (clipped) high peaks. The results show that the compressive loads decrease fatigue life of the specimen by ,300%. Furthermore, by running tests with clipped peaks it was found that the fatigue life was shorten significantly due to reduction of crack growth retardation caused by highest tensile peaks. Multiple tests were conducted in order to establish a scatter in the experimental data under spectrum loads. [source]

Laser shock peening on fatigue crack growth behaviour of aluminium alloy

FATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 8 2004
Y. TAN
ABSTRACT The effect of laser shock peening (LPS) in the fatigue crack growth behaviour of a 2024-T3 aluminium alloy with various notch geometries was investigated. LPS was performed under a ,confined ablation mode' using an Nd: glass laser at a laser power density of 5 GW cm,2. A black paint coating layer and water layer was used as a sacrificial and plasma confinement layer, respectively. The shock wave propagates into the material, causing the surface layer to deform plastically, and thereby, develop a residual compressive stress at the surface. The residual compressive stress as a function of depth was measured by X-ray diffraction technique. The fatigue crack initiation life and fatigue crack growth rates of an Al alloy with different preexisting notch configurations were characterized and compared with those of the unpeened material. The results clearly show that LSP is an effective surface treatment technique for suppressing the fatigue crack growth of Al alloys with various preexisting notch configurations. [source]

Exfoliation corrosion of 7150 Al alloy with various tempers and its electrochemical impedance spectroscopy in EXCO solution

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 6 2009
J. F. Li
Abstract The exfoliation corrosion susceptibility and electrochemical impedance spectroscopy (EIS) of 7150 Al alloys with T6, T73, and RRA (retrogression at 175,°C for 3 h) tempers in EXCO solution were investigated. The anodic equilibrium precipitate ,(MgZn2) is continuous or closely spaced at the grain boundaries in the 7150-T6 Al alloy, resulting in its greatest susceptibility to exfoliation corrosion. The grain boundary , precipitates in the RRA and T73 treated 7150 Al alloys are coarsened and show a clear discontinuous nature; they possess similar exfoliation corrosion sensitivity and their exfoliation corrosion resistance is greatly increased. At the beginning of immersion in EXCO solution, the EIS plot of the 7150 Al alloys is composed of a capacitive arc in the high to medium frequency range and an inductive component in the medium to low frequency range. As immersion time is increased, exfoliation corrosion with different corrosion ratings occurs on the surface of the 7150 Al alloy with various tempers, two capacitive arcs appear in the high to medium and medium to low frequency ranges, respectively. The fitted medium to low frequency capacitance C2 of 7150-T6 Al alloy, corresponding to the new surface caused by the exfoliation corrosion, is much greater than that of the T73 and RRA treated 7150 Al alloy, which is consistent with the greatest exfoliation corrosion susceptibility of the 7150-T6 Al alloy. [source]

The effect of interstitial hydrogen on the electronic structure of the B2 FeAl alloy

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 10 2007
Estela A. González
Abstract The electronic structure and bonding in a B2 Fe,Al alloy with and without hydrogen as an interstitial atom were studied within the framework of the density functional theory and the findings compared with previous results in Fe an Al. The hydrogen absorption turns out to be a favorable process. The hydrogen was found near an Al octahedral site, the Al,H distance being shorter than that of Fe,H. The density of states (DOS) curves show several peaks below the d metal band which is made up mostly of hydrogen based states (>50% H1s) while the metal contribution includes mainly s- and p-orbitals. An electron transfer of nearby 0.14 e, comes from the metal to the H. The overlap population values reveal metal,metal bond breaking, the intermetallic bond being the most affected. The H bond mainly with the Al atoms and the reported Fe,H overlap population is much lower than that corresponding to FePd alloys and BCC Fe. The changes in the overlap population show the Fe,Al bond is weakening nearly 53% after H absorption, while the Fe,Fe bond is only weakened 23%. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Where Does the Lithium Go?

ADVANCED ENGINEERING MATERIALS, Issue 4 2010
A Study of the Precipitates in the Stir Zone of a Friction Stir Weld in a Li-containing 2xxx Series Al Alloy
The main strengthening precipitates of aluminum alloy 2198-T8, which are of the T1 phase, dissolve during friction stir welding, sending many Li atoms into solid solution. The stir zone precipitates are characterized using high-resolution transmission electron microscopy, energy dispersive spectroscopy, and selected area diffraction techniques to begin answering questions about the microstructural evolution and the relationship between microstructure and mechanical properties in friction stir welding of the next generation of lightweight Li-containing Al alloys. [source]

Synthesis and Properties of Al-Ni-La Bulk Metallic Glass,

ADVANCED ENGINEERING MATERIALS, Issue 7 2009
Juan Mu
Al85.5Ni9.5La5 bulk metallic glass (BMG) with a size of 1,mm is synthesized for the first time through a two-step melt treatment. The treatment effectively removes the local structural ordering and high-temperature phases, as well as allowing a high cooling rate. The sample displays good mechanical properties. The compressive fracture strength is about 1180,MPa, which is higher than that of most Mg-based BMGs and Al alloys. [source]

Laser shock peening on fatigue crack growth behaviour of aluminium alloy

Microstructure of ball milled and compacted Co,Ni,Al alloys from the , range

JOURNAL OF MICROSCOPY, Issue 2 2009
W. MAZIARZ
Summary Two powder alloys from the , phase region of compositions Co28.5Ni36.5Al35 and Co35Ni30Al35 were ball milled for 80 h in a high energy ball mill. The formation of amorphous structure was observed after 40 h of milling and further milling did not change their structure. The analytical and high-resolution transmission electron microscopy (TEM, HREM) examination of powder structure showed that nanoparticles of L10 phase of size of about 5 nm were present within the amorphous matrix. The vacuum hot pressing of the milled powders under pressure of 400 MPa at 700°C for 12 min resulted in the formation of compacts with density of about 70% of the theoretical one. The additional heat treatment at 1300°C for 6 h followed by water quenching, led to significant improvement of density and induced the martensitic transformation manifested by a broad heat effect. The characteristic temperatures of the transformation were determined using DSC measurements, which revealed only small differences within the examined alloys compositions. TEM structure studies of heat-treated alloys allowed to identify the structure of an ordered , (B2) phase and L10 martrensite. [source]