Results 221 to 230 of about 904,230 (261)

Sigma-phase in duplex-stainless steels

Zeitschrift für Metallkunde, 2004
Abstract The ferritic-austenitic duplex-steels have a very complex precipitation and transformation behaviour, which requires professional treatment. Especially the precipitation of the σ-phase causes considerable changes with regard to the mechanical as well as the corrosive properties, which are to be considered during the treatment of
Michael Pohl, Oliver Storz
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The sigma phase revisited: an alternative pathway to a trial structure

Acta Crystallographica Section B Structural Science, 1996
A new derivation of a trial structure of the sigma phase is described. It is based on the stochastic method in a form which is particularly useful in the derivation of trial structures of high symmetry, provided that the radii of the component metals are of the appropriate relative magnitudes.
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Sigma-Phase in Transitional Metal Alloys

Nature, 1951
THE existence of a phase isomorphous with the sigma-phase of the iron–chromium system has now been proved in a number of other alloys containing transitional elements. It has been observed in the following systems:
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Dense Delta-Sigma Phased Arrays

IEEE Transactions on Antennas and Propagation, 2013
The high cost of high-resolution phase shifters required to maintain precise control over the array beam pattern in traditional phased arrays preclude their use in a variety of emerging millimeter-wave applications. We develop a phased array architecture that obviates the need for such precise phase shifters, based on the use of sub-half-wavelength ...
James D. Krieger, Chen-Pang Yeang, Gregory W. Wornell   +2 more
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Sigma Phase in Vanadium–Nickel Alloys

Nature, 1952
AN X-ray examination has been made of a vanadium–nickel sigma phase single crystal containing 60 atomic per cent vanadium. The crystal was of irregular shape and plate-like form, the two larger dimensions being greater than ½ mm. Laue and rotation photographs using copper radiation showed that the unit cell was tetragonal with a = 8.95 kX. and c = 4.63
W. B. PEARSON, J. W. CHRISTIAN
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The magnetic properties of sigma phase alloys

IEEE Transactions on Magnetics, 1966
Measurements of intrinsic magnetization as a function of temperature and composition have been made on a number of first series sigma phase alloys. In conflict with earlier work, ferromagnetism has been observed in only two systems, Fe Cr and Fe V. The results on Fe Cr exhibit many interesting features, and appear to be consistent with a ferrimagnetic ...
D. Read, E. Thomas
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Formation of sigma-phase in alloy KhN65VMTYu

Metal Science and Heat Treatment, 1987
1. Formation of σ-phase in high-temperature alloy KhN65VMTYu is governed to a considerable degree by its chemical composition. 2. Calculation of the chemical composition by the Phacomp method makes it possible to predict quite accurately the probability of σ-phase formation from the number of electron vacancies (Nv). For alloy KhN65VMTYu
L. S. Bulavina, I. N. Mel'kumov
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Poly-phase sigma-delta modulation

IEEE Transactions on Circuits and Systems II: Analog and Digital Signal Processing, 1997
A new circuit is described for the implementation of analog sigma-delta modulation. It is based upon the use of a poly-phase sampler with the aim of obtaining high over-sampling ratios at low clock frequencies. A detailed analysis of second-order systems is made to predict its performance.
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A delta-sigma modulator with a phase-to-digital and digital-to-phase quantizer

2011 IEEE 9th International New Circuits and systems conference, 2011
A phase-based delta-sigma analog-to-digital converter (ADC) architecture with a combination voltage-controlled and digitally-controlled delay lines (VCDL-DCDL) is presented. The architecture uses this VCDL-DCDL combination as the phase-domain counterparts of an ADC-DAC in a traditional delta-sigma modulator.
Yiqiao Lin, Mohammed Ismail
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Phase Stability of the Sigma Phase in Fe-Cr Based Alloys

MRS Proceedings, 1995
AbstractThe FeCr sigma phase is a good example of a complex structure: it. has 30 atoms in the unit cell and 5 inequivalent lattice sites, and it belongs to the class of tetrahedrally close packed structures, also known as Frank-Kaspar structures. So far.
Marcel Il. F, Sluiter. Koivan Esfurjani, Yoshiyuki Kawazoe   +2 more
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