Synchrotron x-ray Study of Elastic Phase Strains in the Bulk of an Externally Loaded Cu/Mo Composite

1999 ◽  
Vol 590 ◽  
Author(s):  
A. Wanner ◽  
D.C. Dunand
Keyword(s):  
Plastic Deformation ◽  
Load Transfer ◽  
Tensile Deformation ◽  
Copper Matrix ◽  
High Energy ◽  
Uniaxial Tensile ◽  
X Rays ◽  
Synchrotron Source ◽  
Peak Broadening ◽  
The Matrix

ABSTRACTHigh-energy, high-flux x-rays from a third-generation synchrotron source were used to measure average elastic strains in the bulk of 1.5 mm thick composites consisting of a copper matrix reinforced with 7.5 vol.% molybdenum particles. From the evolution of lattice strains in both phases during uniaxial tensile deformation, the internal load transfer between phases and reinforcement damage were characterized during elastic and plastic deformation of the composite. The graininess of the diffraction rings, which is related to the Bragg peak broadening, was quantified as a function of applied stress and related to plastic deformation in the matrix.

Synchrotron X-ray Diffraction Measurement of Reinforcement Strains in Uniaxially Stressed Bulk Metallic Glass Composites

2001 ◽  
Vol 678 ◽  
Author(s):  
Dorian K. Balch ◽  
Ersan Üstündag ◽  
David C. Dunand
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Load Transfer ◽  
High Energy ◽  
Uniaxial Tensile ◽  
Diffraction Measurement ◽  
X Rays ◽  
Glass Composites ◽  
Bulk Metallic Glass Composites ◽  
The Matrix

AbstractHigh-energy synchrotron x-rays were used to measure internal reinforcement strains in bulk metallic glass composites containing tungsten or tantalum particles during in-situ uniaxial tensile loading. Load transfer from the matrix to the stiffer but weaker particles was characterized in both their elastic and plastic regimes and compared to theoretical predictions.

scholarly journals Residual Stress Evolution during Decomposition of Ti(1-x)Al(x)N Coatings Using High-Energy X-Rays

2006 ◽  
Vol 524-525 ◽  
pp. 619-624 ◽  
Author(s):  
Mark R. Terner ◽  
Peter Hedström ◽  
Jonathan Almer ◽  
J. Ilavsky ◽  
Magnus Odén
Keyword(s):  
Residual Stress ◽  
Phase Separation ◽  
Elevated Temperatures ◽  
High Energy ◽  
Film Plane ◽  
X Rays ◽  
X Ray Diffraction ◽  
Synchrotron Source ◽  
Simultaneous Acquisition ◽  
Initial Stage

Residual stresses and microstructural changes during phase separation in Ti33Al67N coatings were examined using microfocused high energy x-rays from a synchrotron source. The transmission geometry allowed simultaneous acquisition of x-ray diffraction data over 360° and revealed that the decomposition at elevated temperatures occurred anisotropically, initiating preferentially along the film plane. The as-deposited compressive residual stress in the film plane first relaxed with annealing, before dramatically increasing concurrently with the initial stage of phase separation where metastable, nm-scale c-AlN platelets precipitated along the film direction. These findings were further supported from SAXS analyses.

scholarly journals Design and Performance of the X-ray Polarimeter X-Calibur

2014 ◽  
Vol 03 (02) ◽  
pp. 1440008 ◽  
Author(s):  
M. Beilicke ◽  
F. Kislat ◽  
A. Zajczyk ◽  
Q. Guo ◽  
R. Endsley ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Detection Efficiency ◽  
Grazing Incidence ◽  
High Energy ◽  
X Rays ◽  
Field Orientation ◽  
Synchrotron Source ◽  
X Ray ◽  
And Performance ◽  
Detector Assembly

X-ray polarimetry promises to give qualitatively new information about high-energy astrophysical sources, such as binary black hole systems, micro-quasars, active galactic nuclei, neutron stars, and gamma-ray bursts. We designed, built and tested a X-ray polarimeter, X-Calibur, to be used in the focal plane of the balloon-borne InFOCμS grazing incidence X-ray telescope. X-Calibur combines a low-Z scatterer with a Cadmium Zinc Telluride (CZT) detector assembly to measure the polarization of 20–80 keV X-rays making use of the fact that polarized photons scatter preferentially perpendicular to the electric field orientation. X-Calibur achieves a high detection efficiency of ≃80%. The X-Calibur detector assembly is completed, tested, and fully calibrated. The response to a polarized X-ray beam was measured successfully at the Cornell High Energy Synchrotron Source. This paper describes the design, calibration and performance of the X-Calibur polarimeter. In principle, a similar space-borne scattering polarimeter could operate over the broader 2–100 keV energy band.

High-resolution X-ray diffraction investigation on the evolution of the substructure of individual austenite grains in TRIP steels during tensile deformation

2014 ◽  
Vol 47 (3) ◽  
pp. 965-973 ◽  
Author(s):  
Romain Blondé ◽  
Enrique Jimenez-Melero ◽  
Richard Huizenga ◽  
Lie Zhao ◽  
Jonathan Wright ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
High Resolution ◽  
Tensile Deformation ◽  
Subgrain Size ◽  
High Energy ◽  
Uniaxial Tensile ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trip Steels ◽  
Austenite Grains

The martensitic transformation behaviour of the metastable austenite phase in low-alloyed transformation-induced plasticity (TRIP) steels has been studiedin situusing high-energy X-ray diffraction during deformation. The austenite stability during tensile deformation has been evaluated at different length scales. A powder diffraction analysis has been performed to correlate the macroscopic behaviour of the material to the observed changes in the volume phase fraction. Moreover, the austenite deformation response has been studied at the length scale of individual grains, where an in-depth characterization of four selected grains has been performed, including grain volume, local carbon concentration and grain orientation. For the first time, a high-resolution far-field detector was used to study the initial and evolving structure of individual austenite grains during uniaxial tensile deformation. It was found that the austenite subgrain size does not change significantly during tensile deformation. Most austenite grains show a complete martensitic transformation in a single loading step.

Anisotropic Tensile Deformation of Lotus-Type Porous Copper

2011 ◽  
Vol 695 ◽  
pp. 545-548
Author(s):  
Masakazu Tane ◽  
Rika Okamoto ◽  
Hideo Nakajima
Keyword(s):  
Cross Section ◽  
Tensile Deformation ◽  
Tensile Specimen ◽  
Copper Matrix ◽  
Constant Volume ◽  
Incompressibility Condition ◽  
Orientation Direction ◽  
Porous Copper ◽  
Cylindrical Pores ◽  
The Matrix

The tensile deformation of lotus-type porous copper with cylindrical pores oriented in one direction was investigated. Deformation was occured homogeneously in the copper matrix for loadings parallel to the orientation direction of pores (pore direction), while deformation was localized in the matrix around pores for loadings perpendicular to the pore direction. In the case of parallel loading the decrease in cross section of tensile specimen was smaller than that of nonporous copper, because of the constant-volume law (i.e. incompressibility condition) for deformation was not applicable to the deformation of pores. In the case of perpendicular loading, the deformed regions were disconnected and constant-volume law holds only in the matrix around the pores, and thus, the cross section hardly decreases during the tensile deformation.

Accurate charge densities from powder X-ray diffraction – a new version of the Aarhus vacuum imaging-plate diffractometer

2017 ◽  
Vol 73 (4) ◽  
pp. 521-530 ◽  
Author(s):  
Kasper Tolborg ◽  
Mads R. V. Jørgensen ◽  
Sebastian Christensen ◽  
Hidetaka Kasai ◽  
Jacob Becker ◽  
...  
Keyword(s):  
Electron Density ◽  
High Energy ◽  
Imaging Plate ◽  
High Symmetry ◽  
X Rays ◽  
X Ray Diffraction ◽  
Core Electron ◽  
X Ray ◽  
Peak Broadening ◽  
Structure Factors

In recent years powder X-ray diffraction has proven to be a valuable alternative to single-crystal X-ray diffraction for determining electron-density distributions in high-symmetry inorganic materials, including subtle deformation in the core electron density. This was made possible by performing diffraction measurements in vacuum using high-energy X-rays at a synchrotron-radiation facility. Here we present a new version of our custom-built in-vacuum powder diffractometer with the sample-to-detector distance increased by a factor of four. In practice this is found to give a reduction in instrumental peak broadening by approximately a factor of three and a large improvement in signal-to-background ratio compared to the previous instrument. Structure factors of silicon at room temperature are extracted using a combined multipole–Rietveld procedure and compared withab initiocalculations and the results from the previous diffractometer. Despite some remaining issues regarding peak asymmetry, the new diffractometer yields structure factors of comparable accuracy to the previous diffractometer at low angles and improved accuracy at high angles. The high quality of the structure factors is further assessed by modelling of core electron deformation with results in good agreement with previous investigations.

scholarly journals Wear Dry Behavior of the Al-6061-Al2O3 Composite Synthesized by Mechanical Alloying

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1652
Author(s):  
Víctor Hugo Mercado-Lemus ◽  
Cynthia Daisy Gomez-Esparza ◽  
Juan Carlos Díaz-Guillén ◽  
Jan Mayén-Chaires ◽  
Adriana Gallegos-Melgar ◽  
...  
Keyword(s):  
Mechanical Alloying ◽  
Load Transfer ◽  
Wear Behavior ◽  
Aluminum Matrix ◽  
High Energy ◽  
Aluminum Matrix Composite ◽  
Al2o3 Nanoparticles ◽  
Protective Behavior ◽  
Al 6061 ◽  
The Matrix

The present research deals with the comparative wear behavior of a mechanically milled Al-6061 alloy and the same alloy reinforced with 5 wt.% of Al2O3 nanoparticles (Al-6061-Al2O3) under different dry sliding conditions. For this purpose, an aluminum-silicon-based material was synthesized by high-energy mechanical alloying, cold consolidated, and sintered under pressureless and vacuum conditions. The mechanical behavior was evaluated by sliding wear and microhardness tests. The structural characterization was carried out by X-ray diffraction and scanning electron microscopy. Results showed a clear wear resistance improvement in the aluminum matrix composite (Al-6061-Al2O3) in comparison with the Al-6061 alloy since nanoparticles act as a third hard body against wear. This behavior is attributed to the significant increment in hardness on the reinforced material, whose strengthening mechanisms mainly lie in a nanometric size and homogeneous dispersion of particles offering an effective load transfer from the matrix to the reinforcement. Discussion of the wear performance was in terms of a protective thin film oxide formation, where protective behavior decreases as a function of the sliding speed.

Sign in / Sign up

Export Citation Format

Share Document