scholarly journals Solidification of Al Alloys Under Electromagnetic Pulses and Characterization of the 3D Microstructures Using Synchrotron X-ray Tomography

2015 ◽  
Vol 46 (7) ◽  
pp. 2908-2915 ◽  
Author(s):  
Theerapatt Manuwong ◽  
Wei Zhang ◽  
Peter Lobo Kazinczi ◽  
Andrew J. Bodey ◽  
Christoph Rau ◽  
...  
Keyword(s):  
Al Alloys ◽  
Electromagnetic Pulses ◽  
X Ray

3D X-ray microtomography and mechanical characterization of corrosion-induced damage in 7075 aluminium (Al) alloys

2018 ◽  
Vol 139 ◽  
pp. 97-113 ◽  
Author(s):  
Renuka Vallabhaneni ◽  
Tyler J. Stannard ◽  
C. Shashank Kaira ◽  
Nikhilesh Chawla
Keyword(s):  
Mechanical Characterization ◽  
Al Alloys ◽  
X Ray

scholarly journals Characterization of Al and Mg Alloys from Their X-Ray Emission Bands

2009 ◽  
Vol 15 (1) ◽  
pp. 36-45 ◽  
Author(s):  
Philippe Jonnard ◽  
Karine Le Guen ◽  
Raynald Gauvin ◽  
Jean-François Le Berre
Keyword(s):  
Linear Combination ◽  
Reference Materials ◽  
Emission Spectroscopy ◽  
Single Phase ◽  
Composition Range ◽  
Al Alloys ◽  
X Ray ◽  
Al Content ◽  
Valence States

AbstractThe valence states of Mg-Al alloys are compared to those of reference materials (pure Mg and Al metals, and intermetallics). Two methods based on X-ray emission spectroscopy are proposed to determine the phases and their proportion: first, by analyzing the Al valence spectra of the Mg-rich alloys and the Mg valence spectra of the Al-rich alloys; second, by fitting with a linear combination of the reference spectra the Al spectra of the Al-rich alloys and the Mg spectra of the Mg-rich alloys. This enables us to determine that Al and Al3Mg2 are present in the 0–43.9 wt% Al composition range and Mg and Al12Mg17 are present in the 62.5–100 wt% Al composition range. In the 43.9–62.5% Al range, the alloy is single phase and an underestimation of the Al content of the alloy can be estimated from the comparison of the bandwidth of the alloy spectrum to the bandwidths of the reference spectra.

Fabrication B-Ni-Al Shielding Materials by Vacuum Metal Infiltration

2013 ◽  
Vol 641-642 ◽  
pp. 410-413
Author(s):  
Chao Wang ◽  
Jian Zhang ◽  
Xiang Xin Xue ◽  
Xiao Zhou Cao
Keyword(s):  
Electron Microscopy ◽  
Bending Strength ◽  
Microstructural Characterization ◽  
Al Alloys ◽  
X Ray Diffraction ◽  
X Ray ◽  
Al Composite ◽  
Metal Infiltration ◽  
Scanning Electron

In this paper, B-Ni-Al shield materials were fabricated by vacuum metal infiltration. The B-Ni-Al Composite were fabricated by preheating BN+Ni at 1550°C for one hour before infiltrating Al alloys into the preforms in a vacuum at 1100°C for two hours. Microstructural characterization of the materials obtained was performed using X-ray diffraction, scanning electron microscopy(SEM). Mechanical properties were evaluated by fracture toughness and bending strength. AlN was produced with interfacial reactions between Al and BN.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Digital x-ray mapping of nanometer-size supported bimetallic catalysts

1988 ◽  
Vol 46 ◽  
pp. 530-531
Author(s):  
L. T. Germinario
Keyword(s):  
Background Radiation ◽  
Metal Cluster ◽  
Single Element ◽  
Beam Diameter ◽  
X Rays ◽  
X Ray ◽  
Major Interest ◽  
Induced Changes

Understanding the role of metal cluster composition in determining catalytic selectivity and activity is of major interest in heterogeneous catalysis. The electron microscope is well established as a powerful tool for ultrastructural and compositional characterization of support and catalyst. Because the spatial resolution of x-ray microanalysis is defined by the smallest beam diameter into which the required number of electrons can be focused, the dedicated STEM with FEG is the instrument of choice. The main sources of errors in energy dispersive x-ray analysis (EDS) are: (1) beam-induced changes in specimen composition, (2) specimen drift, (3) instrumental factors which produce background radiation, and (4) basic statistical limitations which result in the detection of a finite number of x-ray photons. Digital beam techniques have been described for supported single-element metal clusters with spatial resolutions of about 10 nm. However, the detection of spurious characteristic x-rays away from catalyst particles produced images requiring several image processing steps.

Plant Pathology Diagnosed by X-Ray Microanalysis

1987 ◽  
Vol 45 ◽  
pp. 974-975
Author(s):  
J. H. Resau ◽  
N. Howell ◽  
S. H. Chang
Keyword(s):  
Electron Microscopy ◽  
Plant Pathology ◽  
Biochemical Characterization ◽  
Nutrient Deficiency ◽  
Green Leaf ◽  
Parasitic Infestation ◽  
X Ray

Spinach grown in Texas developed “yellow spotting” on the peripheral portions of the leaves. The exact cause of the discoloration could not be determined as there was no evidence of viral or parasitic infestation of the plants and biochemical characterization of the plants did not indicate any significant differences between the yellow and green leaf portions of the spinach. The present study was undertaken using electron microscopy (EM) to determine if a micro-nutrient deficiency was the cause for the discoloration.Green leaf spinach was collected from the field and sent by express mail to the EM laboratory. The yellow and equivalent green portions of the leaves were isolated and dried in a Denton evaporator at 10-5 Torr for 24 hrs. The leaf specimens were then examined using a JEOL 100 CX analytical microscope. TEM specimens were prepared according to the methods of Trump et al.

EXELFS Studies of Carbon Fibers

1990 ◽  
Vol 48 (2) ◽  
pp. 72-73
Author(s):  
V. Serin ◽  
K. Hssein ◽  
G. Zanchi ◽  
J. Sévely
Keyword(s):  
Carbon Fibers ◽  
Energy Analysis ◽  
Electron Excitation ◽  
Complex Structures ◽  
High Modulus ◽  
Promising Technique ◽  
X Ray ◽  
Fine Structures ◽  
X Ray Absorption

The present developments of electron energy analysis in the microscopes by E.E.L.S. allow an accurate recording of the spectra and of their different complex structures associated with the inner shell electron excitation by the incident electrons (1). Among these structures, the Extended Energy Loss Fine Structures (EXELFS) are of particular interest. They are equivalent to the well known EXAFS oscillations in X-ray absorption spectroscopy. Due to the EELS characteristic, the Fourier analysis of EXELFS oscillations appears as a promising technique for the characterization of composite materials, the major constituents of which are low Z elements. Using EXELFS, we have developed a microstructural study of carbon fibers. This analysis concerns the carbon K edge, which appears in the spectra at 285 eV. The purpose of the paper is to compare the local short range order, determined by this way in the case of Courtauld HTS and P100 ex-polyacrylonitrile carbon fibers, which are high tensile strength (HTS) and high modulus (HM) fibers respectively.

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