Showing papers on "Alloy published in 1968"
TL;DR: In other alloying variations some of the nickel is replaced with cobalt, in the formula TiNixCo1−x, is an effective substitution element for lowering the transition temperature as discussed by the authors.
368 citations
TL;DR: In this article, a glass-liquid transition in the Au0.77Ge0.136Si0.094 alloy was reported and the transition was manifested thermally by an abrupt rise of 5.5 cal/g•atom·°K in specific heat, Cp, as the alloy was heated from 285° to 297°K. The apparent glass transition temperature was increased by 1°−3° by increasing the heating rate by a factor of 16.
Abstract: Gold‐rich (73–81 at.% Au) alloys of gold–germanium–silicon were “splat” cooled to an amorphous solid form. Thermal and rheological evidence of a glass‐liquid transition in the Au0.77Ge0.136Si0.094 alloy is reported. The transition was manifested thermally by an abrupt rise of 5.5 cal/g‐atom·°K in specific heat, Cp, as the alloy was heated from 285° to 297°K. Just above 297°K, Cp starts to fall with increasing T on a reasonable extrapolation of the high‐temperature Cp–T relation of the liquid alloy. This thermal behavior could be repeated on the same sample after it had been carried through the transition and chilled again. The apparent glass‐transition temperature was increased by 1°–3° by increasing the heating rate by a factor of 16. The viscosity η of the amorphous alloy increases rapidly with falling temperature from 0.9 × 109 P at 305°K to 1.4 × 1013 P at 285°K and is described by the equation: η = 0.52 exp [136 / (T − 241.3)] P. The steady isothermal viscosity is independent of stress over the range...
336 citations
TL;DR: In this article, the precipitation process and age hardening mechanism in a Mg-9 wt.% Al alloy were studied principally by transmission electron microscopy, and no evidence for the formation of either G.P. zones or a transition lattice of the Mg17Al12 precipitate was obtained.
309 citations
TL;DR: In this article, it was found that at room temperature the critical resolved shear stress (CRSS) is a linear function of the concentration of nitrogen plus residual carbon, and the alloy hardening is 460,000 kgf/cm2 per unit atomic fraction of interstitials.
119 citations
Patent•
05 Jul 1968TL;DR: An interference fit can be provided between metal components where at least one of the components is formed of a precipitation-hardenable metal alloy which undergoes a substantially permanent dimensional change in addition to a reversible dimensional change upon heat treatment at elevated temperatures as mentioned in this paper.
Abstract: An interference fit can be provided between metal components where at least one of the components is formed of a precipitation-hardenable metal alloy which undergoes a substantially permanent dimensional change in addition to a reversible dimensional change upon heat treatment at elevated temperatures. The interference fit itself will be irreversible if both components are formed of the preciptitation-hardenable alloy and reversible if only one of the components is formed of the alloy.
89 citations
Patent•
29 Oct 1968
TL;DR: Aluminum and aluminum alloys of varying binary, ternary and multicomponent types having from 0.01 to about 5.0 percent by weight of scandium characterized by improved physical properties and methods of thermally treating the same as discussed by the authors.
Abstract: Aluminum and aluminum alloys of varying binary, ternary and multicomponent types having from 0.01 to about 5.0 percent by weight of scandium characterized by improved physical properties and methods of thermally treating the same.
80 citations
TL;DR: In this paper, it was shown under which conditions this type of internal oxidation may occur, based on a theoretical analysis of concurrent diffusion processes, under the conditions that the internal diffusion may occur.
68 citations
TL;DR: The radial distribution function for an electrodeposited amorphous nickel-phosphorus (149 wt% P) alloy has been determined in this article, and the atomic distribution was found to be similar to that in a liquid metal.
Abstract: The radial distribution function for an electrodeposited amorphous nickel‐phosphorus (149 wt% P) alloy has been determined The atomic distribution was found to be similar to that in a liquid metal, and more disordered than that observed in an amorphous nickel‐phosphorus alloy produced by chemical deposition Two transformations (both exothermic) were observed in this alloy; the first of which occurred at 280°±2°C with an energy of 185 cal/g (960 cal/g atom) and the second at 410°±5°C with an energy of 60 cal/g (310 cal/g atom) As deposited, the alloy exhibits only a very weak small‐angle x‐ray scattering, apparently not due to the presence of the phosphorus
68 citations
TL;DR: In this paper, the role of ferrite in nucleating sigma was investigated, and it was concluded that sigma is precipitated directly from austenites of low (Ni + Cr) content, whereas in alloys of high (Ni+Cr) content sigma forms via the b.c. metastable ferrite phase.
61 citations
TL;DR: In this paper, the adiabatic elastic constants of molybdenum and rhenium alloyed in solid solution with 7.0, 16.6, and 26.9 at.
Abstract: The adiabatic elastic constants of molybdenum and molybdenum alloyed in solid solution with 7.0, 16.6, and 26.9 at.% rhenium were measured in the temperature range −190°C to +100°C. Rhenium additions decrease (c11−c12)/2 and the twinning shear (c11−c12+c44)/3, and increase the bulk modulus and c44. The 26.9 at.% alloy is elastically isotropic. Alloy additions strengthen nearest‐neighbor interactions and weaken second‐nearest‐neighbor interactions. Debye temperatures calculated from the measured elastic constants agree well with those determined by calorimetry. Thermal expansion of the alloys was found to be essentially the same as for molybdenum in this temperature range.
59 citations
TL;DR: In this article, the structure and composition of thin oxide films formed during high temperature oxidation of an Fe-15%Cr-4%Al-1%Y alloy in CO 2 are reported.
TL;DR: In this paper, a study of the oxidation of Cr and an Fe-50%Cr alloy has been carried out using micro-gravimetry, microscopy and electron probe microanalysis.
TL;DR: In this paper, the dependence of the yield stress of binary solid solution crystals on temperature and alloy concentration is explained in terms of a simple model in which the breakaway of dislocations from short rows of pinning points is rate determining.
Abstract: The dependence of the yield stress of binary solid solution crystals on temperature and alloy concentration is explained in terms of a simple model in which the breakaway of dislocations from short rows of pinning points is rate determining. With an assumed binding energy of about 001 ev between dislocations and zinc atoms the calculated yield stress of α-brass single crystals agrees quantitatively with measured values in the range 0-400°K. The yield stress of dilute solid solutions, particularly iron alloys, and a possible bearing of the present theory on the problem of the temperature dependence of the Peierls stress, are discussed briefly.
TL;DR: The sulfide cracking behavior of a number of carbon and low alloy steels is described in this paper, where it is shown that the susceptibility of a steels to sulfide crackability depends primarily on the microstructure of the steels.
Abstract: The sulfide cracking behavior of a number of carbon and low alloy steels is described Susceptibility to sulfide cracking is shown to depend primarily on microstructure Steels with uniform, spheroidized carbides in a ferrite matrix have the greatest cracking resistance at any given strength level The presence of untempered martensite in the microstructure drastically reduces cracking resistance Lamellar carbides resulting from either normalizing and tempering or isothermal transformation give rise to cracking resistance intermediate between steels fully quenched and tempered and steels containing untempered martensite
TL;DR: In this article, a precipitated phase was identified as Al 11 V by electron diffraction and was shown to have a hardness three times that of annealed aluminum and retained this hardness after high-temperature heat treatments.
TL;DR: A micrographic study of some alloys of the Cu-Mn-Sb system in both the as-cast and heat-treated conditions, revealed the presence of a single phase alloy (lattice parameter, a = 6·088 ± 0·003 A ) at the composition CuMnSb as mentioned in this paper.
TL;DR: In this paper, the behavior of pure Fe, a rimming steel and three low-alloy steels has been fully characterized in CO2 containing small amounts of CO and H2O at 500 °C.
TL;DR: Transgranular stress corrosion cracks are formed in Ti-5Al-2.5Sn alloy immersed in a 3 percent NaCl aqueous solution when tensile specimens are dynamically strained over a narrow range of...
Abstract: Transgranular stress corrosion cracks are formed in Ti-5Al-2.5Sn alloy immersed in a 3 percent NaCl aqueous solution when tensile specimens are dynamically strained over a narrow range of ...
TL;DR: In this article, an alloy of composition 24% Ni, 17% Cr, 2% Ti (bal. Fe) was heat-treated to produce precipitation of the γ′ (ordered Ni 3 Ti)-phase in austenite, and proof stressageing time curves were obtained for specimens aged at 725 and 750°C.
TL;DR: In this paper, the low temperature thermal expansion of several aluminium, nickel, copper, and iron base alloys was measured from liquid hydrogen temperature to room temperature, and the thermal expansion coefficient, (1/L293)/(dL/dT) was tabulated as a function of temperature.
TL;DR: In this article, uniform single-layered scales, consisting of containing a low concentration of dissolved iron, are produced and the deviations from a parabolic law are discussed in light of general oxidation theory and the self-diffusion coefficients of ions in the scales are derived.
Abstract: The oxidation of Fe‐28% Cr in oxygen at 800°–1200°C has been studied in detail by thermogravimetric methods, metallography, and electron probe microanalysis. The oxidation rate is critically related to the surface finish and alloy purity but not significantly to variations in specimen size or geometry. Uniform single‐layered scales, consisting of containing a low concentration of dissolved iron, are produced. The oxidation rate shows minor negative deviations from a parabolic law, with an activation energy of 36 ± 6 kcal mole−1 for the over‐all diffusion‐controlled process. The deviations from a parabolic law are discussed in light of general oxidation theory and the self‐diffusion coefficients of ions in the scales are derived.
TL;DR: In this article, the dynamic compression of circular cylinders of different types of steel at elevated temperatures and at high strain-rates were investigated using an experimental drop hammer instrumented with an accelerometer and capacitive-type transducer.
TL;DR: In this article, the authors proposed that the equiaxed structure is produced by spinodal decomposition of an eutectoid Zn-Al alloy and showed tensile elongations of > 1000% at a deformation temperature of 250°C.
Abstract: The mode of decomposition of a eutectoid Zn–Al alloy has been related to the superplastic properties of the alloy. Decomposition during slow quenches or at high transformation temperatures produces a typical lamellar eutectoid structure with conventional mechanical properties. Decomposition at room temperature after a rapid quench produces a fine (∼ 1 μ) mixture of equiaxed zinc-rich and aluminium-rich grains and the alloy then shows tensile elongations of > 1000% at a deformation temperature of 250°C. It is proposed that the equiaxed structure is produced by spinodal decomposition.
TL;DR: In this article, the partial spalling that occurs upon cooling after high temperature oxidation has permitted the direct observation of the alloy-oxide interface, as well as the separated interfaces of the Alloy and the oxide.
TL;DR: Incoloy Alloy 825 can be stablized against intergranular attack by eliminating the chromium-depleted area adjacent to the grain boundary, which is caused by the cellular precipitation of chromiumrich M23C6 during sensitizing treatments as discussed by the authors.
Abstract: Incoloy(1) nickel-iron-chromium Alloy 825 can become sensitive to intergranular attack by exposure to temperatures in the 1200–1400 F (649–760 C) range. Sensitivity to intergranular attack (as measured by the Huey test) can be correlated to the presence of a chromium-depleted area adjacent to the grain boundary. This area is caused by the cellular precipitation of chromium-rich M23C6 during sensitizing treatments. The chromium-depleted region is between the M23C6 cells, but because the carbides grow by boundary migration the depletion is not in the plane of the grain boundary. Incoloy Alloy 825 can be stablized against intergranular attack by eliminating the chromium-depleted area. The degree of stabiization is related to the amount of carbon remaining in solution after the stablizing treatment. The titanium content of the alloy helps to effect stabtization. Because it has a greater affinity for carbon than does chromium, the titanium reacts to form stable carbides and thus reduces chromium deple...
TL;DR: In this article, the authors measured the variation of the neck cross section and the belly/neck ratio with alloy concentration in a number of rather dilute (0.1%) alloys of zinc, cadmium, aluminum, nickel, and palladium in copper.
Abstract: The variation of $〈111〉$ neck cross section and of $〈111〉$ belly/neck ratio with alloy concentration have been measured in a number of rather dilute (0.1%) alloys of zinc, cadmium, aluminum, nickel, and palladium in copper. The scattering (Dingle) temperatures for neck and belly oscillations in these alloys have also been measured. The results for the nontransitional additives show good agreement with a rigid-band, simple heterovalent scatterer model. The results for a single palladium alloy were inconclusive, but those for the nickel alloys are best interpreted on the basis of Friedel's "virtual bound level" model, with about 0.4 electrons per nickel atom left in the conduction band. The "effective scattering temperature" of nickel for neck electrons in copper is found to be appreciably lower than that for belly electrons, in contrast with the approximate 1.5:1 ratio found for the nontransitional impurities.
Patent•
04 Mar 1968TL;DR: An optical filter, particularly for use in sunglasses, comprises a gold or copper foil 12 sandwiched between two transparent layers 14, 16, and a metal, semi-metal or alloy layer 18, having a complex refractive index whose real part is within a factor of 10 of its imaginary part, to reduce reflection from the other side of the filter as mentioned in this paper.
Abstract: 1,265,831. Optical filters. EASTMAN KODAK CO. Feb. 27, 1969 [March 4, 1968], No.10481/69. Heading G2J. [Also in Division C7] An optical filter, particularly for use in sunglasses, comprises a gold or copper foil 12 sandwiched between two transparent layers 14, 16, to filter I.R. and U.V. radiation from one side of the filter, and a metal, semi-metal or alloy layer 18, having a complex refractive index whose real part is within a factor of 10 of its imaginary part, to reduce reflection from the other side of the filter. The various layers 12, 14, 16 and 18 are successively deposited on a plastics or glass substrate 20 by vacuum distillation, or in the case of the gold or copper foil by cathodic sputtering, electrolysis or chemical methods. The order of deposition may be reversed, Fig. (not shown) and a protective plastics or glass layer may be provided at the side remote from the substrate, Figs.5 and 6 (not shown). The layers 14, 16 may consist of the oxides of titanium, lead or bismuth or zinc sulphide, and the layer 18 may be constituted by Ni, Fe, Cr, Ti, Al, La, In, Sn, Pb, Ta, W, Co, Mo, Os, Ir, Pt, Yt, Zr, Ni, Zn, Cd, V, Hf, Re, Tl, Si, Ge, As, Sb, or Te or an alloy or any two or more thereof.
TL;DR: In this article, an attempt has been made to clarify the causes of the complicated precipitation process in ordinary Al-Zn-Mg alloys, especially their thermal stability, and an AlMgZn2 pseudo-binary alloy system was selected in order to check the behavior of an intermediate M' phase and to compare the ageing sequence in this alloy with that in Al-A12Mg3Zn3 quasibinary alloy investigated by Hirano and Takagi(13).
Abstract: Age hardening characteristics in Al-Zn-Mg alloys of various Mg: Zn concentration ratios were studied by Polmear et al.(8)(10(11) and Morinaga et al.(12) and they showed that G.P. zones were responsible for the initial rise in hardness. The former authors correlated the hardening behavior with the stability of G.P. zones. They showed that the stability of the G.P. zones in Al-Zn-Mg alloys increased with increasing Mg content at a fixed concentration of Zn, and vice versa. Hirano and Takagi(13) discussed the stability of the G.P. zone in an Al-8 wt% Zn-4 wt% Mg alloy based on the calorimetric measurements and showed that the stability of the zone increased in proportion to the ageing temperature. In the present investigation, an attempt has been made to clarify the causes of the complicated precipitation process in ordinary Al-Zn-Mg alloys. An AlMgZn2 pseudo-binary alloy system was selected in order to check the behavior of an intermediate M' phase and to compare the ageing sequence in this alloy with that in Al-A12Mg3Zn3 quasi-binary alloy investigated by Hirano and Takagi(13). The additional purpose of this work is to examine the behavior of the G. P. zones, especially their thermal stability.
Patent•
11 Jul 1968TL;DR: In this article, a method of bonding frazile ALUMINUM PARTS, either to the metal of interest or to other METALS, is presented, which does not require pressure and can be accomplished in an inERT ATMOSPHERE.
Abstract: A METHOD OF BONDING FRAGILE ALUMINUM PARTS EITHER TO THEMSELVES OR TO OTHER METALS BY PLACING A CLAD SURFACE OF CONVENTIONAL ALLOY ON THE ALUMINUM PART, A BOND PROMOTING METAL OF IRON OR ARSENIC AND PLACING THE PARTS TO BE JOINED TOGETHER AT A SUFFICIENTLY HIGH TEMPERATURE TO CAUSE MELTING AND FLOWING OF THE CLAD SURFACE TO THEREBY BOND THE COMPONENTS TO EACH OTHER. THE METHOD DOES NOT REQUIRE PRESSURE AND THE JOINING OF THE PARTS IS ACCOMPLISHED IN AN INERT ATMOSPHERE.
TL;DR: In this article, the chromium concentration at the alloy/oxide interface, which is determined largely by the ratio of oxidation rate to alloy interdiffusion rate, governs the type of oxide formed if lifting and cracking of the stressed scale occurs.
Abstract: , containing small quantities of dissolved iron, is the only oxide formed in the oxidation of iron‐chromium alloys in the range 22–68% Cr in oxygen at 800°–1200°C; it is also formed, at least initially, on alloys containing 14 and 18% Cr. The oxide growth is diffusion‐controlled, with an apparent activation energy of 36 kcal mole−1. The increase in oxidation rate with alloy chromium content is slight up to 37% Cr, but becomes more marked with the chromium‐rich alloys. Iron only enters the scale during the very early stages of oxidation, so the weight fraction of iron in the oxide decreases with time. Alloy interdiffusion coefficients have been determined from chromium concentration profiles in the underlying alloy. The activation energies for inter‐ diffusion are 51 and 59 kcal mole−1 for Fe‐27% Cr and Fe‐59% Cr, respectively, but interdiffusion is much slower for the chromium‐rich alloy. The chromium concentration at the alloy/oxide interface, which is determined largely by the ratio of oxidation rate to alloy interdiffusion rate, governs the type of oxide formed if lifting and cracking of the stressed scale occurs. Factors affecting the tendency for scale failure in this way are discussed.