Showing papers on "Laves phase published in 1973"

The constitution and structure of some rare earth-platinum alloys in the range 20–35% rare earth

Abstract: The range of stability of the Laves phase based on GdPt2 has been determined by lattice parameter measurements and these results indicate that the GdPt2 composition lies within the two-phase region. In the arc-melted condition, the alloy corresponding to TbPt3 has the defect, C15-type structure but is converted to the L12-structure by annealing at 1173 K for two hours. TbPt3 with these two structures exhibits markedly different magnetic susceptibility behaviour, at low temperatures.

The Mobility of Grown‐in Dislocations in the Intermetallic Compound MgZn2. III. Dependence of Basal Slip on Chemical Composition within the Homogeneity Range and on Temperature

Abstract: The dislocation velocity, , in basal slip shows a maximum within the range of homogeneity of the Laves phase MgZn2. The temperature dependence of can be described by an thermally activated mechanism with an activation enthalpy of (1.7 ± 0.3) eV in agreement with macroscopic deformation experiments. Die Versetzungsgeschwindigkeit fur Basisgleitttng der Laves-Phase MgZn2, zeigt innerhalb des Homogenitiitsbereiches ein Maximum bei der stochiometrischen Zusammen-setzung. Die Temperaturabhiingigkcit von kann durch einen thermisch aktivierbaren Mechanismus mit einer Aktivierungsenthalpie von (1,7 ± 0,3) eV in Ubereinstimmung mit makroskopischen Verformungsexperimenten beschrieben wcrden.

The hyperfine fields in ferromagnetically ordered cubic Laves phase compounds of gadolinium with non-magnetic metals

Abstract: By means of current zero-field spin-echo NMR technique the hyperfine fields at the Gd and X sites in the ferromagnetic cubic Laves phase compounds of the type GdX2 (X = Al, Pt, Ir, Rh) are derived. The easy direction of magnetization in GdIr2 is STA100! in contrast to [111] in GdAl2.

Wear and corrosion resistant alloy

Abstract: An alloy consisting essentially of, by weight: A. AT LEAST 45 PERCENT COBALT OR NICKEL; B. 20-42 PERCENT MOLYBDENUM; C. 17-25 PERCENT CHROMIUM IF (A) IS COBALT AND 8-22 PERCENT CHROMIUM IF (A) IS NICKEL; AND D. sufficient silicon, not in excess of 12 percent so that 1. THE ALLOY MICROSTRUCTURE CONSISTS OF 10-100 VOLUME PERCENT OF A HARD PHASE WHICH IS PREDOMINANTLY Laves phase and 0-90 volume percent of a relatively soft matrix phase, and 2. THE ALLOY MICROSTRUCTURE CONSISTS OF AT LEAST 10 VOLUME PERCENT OF A Laves phase.

Intermediate phases in some rare earth-ruthenium systems

Abstract: The phase equilibria and crystal structures of intermediate phases were investigated in eight representative RE-Ru systems using powder X-ray diffraction and metallographic techniques. The Fe3C, Mn5C2 and Er5Ru3 structures occur in all but the Ce-Ru systems. Phases analogous to Er5Ru3 possess an unknown crystal structure similar to Er5Rh3(I). MgCu2 and MgZn2 type Laves phases are encountered in the light rare earth and heavy rare earth systems, respectively, and RERu2 phases, where RE = Nd and Sm, possess both the Laves phase structures. An intermediate phase, NdRu, with an unknown structure, occurs only in the Nd-Ru system. A bcc structure with 40 atoms per unit cell is encountered in the phases Er3Ru2 and Y3Ru2. The behavior of cerium in Ce-Ru alloys is unique in that four unidentified structures, not encountered in other RE-Ru systems, have been encountered. Also a phase designated as Ce3Ru is found with the Th7Fe3 type structure.

Magnetoelastic Interactions in the Rare Earth – Iron Cubic Laves Phase Compounds RFe2

Abstract: Finite strain theory is used to obtain expressions for the change in various measured elastic constants as a function of applied magnetic field for cubic ferromagnets Using available data on magnetic anisotropy and magnetostriction, estimates are given for the size of effects that may be expected to be observed in the rare earth – iron cubic Laves phase compounds RFe2 (R = Tb, Dy, Ho, Er, and Tm) The fractional changes in the measured elastic constants for transverse waves are expected to be as large as 10−2 at room temperature

Phase equilibrium and crystal structure of the intermediate phase in the Ta- -Cr system

Abstract: The Laves phases were investigated and the phase equilibrium in the Ta-- Cr system was established by x-ray structural, differential thermal, local x-ray spectral, and microstructure analysis methods and by measurement of the microhardness. Identification was made of the Laves phase by means of the calculation of the intensity of the lines and comparison of these lines with those observed in the x-ray diagrams. New data on the metallides in the Ta--Cr system were shown on the phase diagram. (tr-auth)

Structure and elevated temperature properties of ferritic alloys strengthened by intermetallic compounds

Abstract: Thesis. An investigation was conducted to develop high-temperature 1Ta-- 6Cr, 1Ta--7Cr, and 1Ta-7Cr--0.5 Mo alloys using a dispersion of the Laves phase in a noncarbon-containing, body-centeredcubic iron matrix. An understanding and application of basic principles of materials science and the use of large amounts of information available in the literature were instrumental in the development of Fe-- Ta-- Cr alloys of the investigation. The phase transformations that occurred in the alloys, and the resulting microstructures were studied. The relations between mechanical properties and structure were also examined. Short- time tensile mechanical properties and long-time creep and stress-rupture tests were conducted on the alloys in which microstructural features were varied by changes in the heat-treating procedure. The mechanical properties were compared with those of several commercially available steels. An examination of substructure and precipitate distribution of the alloys before and after creep tests, the determination of apparent activation energy for creep, and an estimation of the stress sensitivity of steady-state creep rates were carried out in order to investigate the mechanism of creep in dispersion-hardened ferritic alloys. Fracture surface morphology was examined after specimens were tested in short-time tension and in creep. (JRD)