Showing papers on "Zirconium alloy published in 1974"
TL;DR: In this article, the authors attributed delayed failures at welds in components of Zi-2.5 wt % Nb are attributed to zirconium hydride forming at the root of a notch adjacent to the welds.
80 citations
69 citations
TL;DR: In this article, the authors established the precipitation processes which occur on ageing metastable β phase specimens above the monotectoid temperature (T mono ) by using optical and electron microscopy together with electron and X-ray diffraction.
59 citations
Patent•
11 Nov 1974TL;DR: In this paper, an improved nuclear fuel element for use in the core of nuclear reactors has been described, which consists of an elongated composite cladding, a central core of a body of nuclear fuel material disposed in and partially filling the container and forming an internal cavity in the container, an enclosure integrally secured and sealed at each end of said container and a nuclear fuel retaining means positioned in the cavity.
Abstract: An improved nuclear fuel element is disclosed for use in the core of nuclear reactors. The improved nuclear fuel has a composite cladding container comprising an outer layer having two coatings on the inside surface with the first coating on the outer layer being a diffusion barrier and the second coating on the first coating being a metal layer. The diffusion barrier is comprised of chromium or a chromium alloy, and the metal layer is selected from the group consisting of copper, nickel, iron and alloys thereof. The nuclear fuel element comprises a container of the elongated composite cladding, a central core of a body of nuclear fuel material disposed in and partially filling the container and forming an internal cavity in the container, an enclosure integrally secured and sealed at each end of said container and a nuclear fuel material retaining means positioned in the cavity. The metal layer and the diffusion barrier of the composite cladding prevent perforations or failures in the outer layer of the cladding from stress corrosion cracking or from fuel pellet-cladding interaction or both. The outer layer of the composite cladding is selected from conventional cladding materials and preferably is a zirconium alloy.
45 citations
TL;DR: Tritium diffusion in niobium, Zircaloy-2 and stainless steel has been studied by measurement of both tritium concentration profiles and surface trittium release rates.
44 citations
TL;DR: In this article, the oxidation of an iron-16% chromium alloy containing a dispersion of yttria particles and of iron- 16 to 18%chromium alloys containing small additions of Yttrium or zirconium has been studied at 1100 and 1200°C in 100 Torr oxygen.
Abstract: The oxidation of an iron-16% chromium alloy containing a dispersion of yttria particles and of iron-16 to 18% chromium alloys containing small additions of yttrium or zirconium has been studied at 1100 and 1200°C in 100 Torr oxygen. The yttria-containing alloy exhibited the excellent oxidation resistance usually associated with oxide-dispersion-containing alloys, having a thin, adherent, virtually iron-free scale which resisted the breakaway rapid oxidation behavior commonly found in Fe-Cr alloys in this composition range. Of the alloying additions intended to form a fine oxide dispersion during oxidation, only zirconium affected the oxidation behavior in a beneficial way, the scale on the yttrium-containing alloy being possibly less protective than that on the equivalent binary alloy.
27 citations
TL;DR: The adiabatic elastic constants were determined for niobium and for its alloys containing 1.4, 3.6, and 6.0% zirconium as mentioned in this paper.
Abstract: The adiabatic elastic constants were determined for niobium and for its alloys containing 1.4, 3.6, and 6.0 at.% zirconium. The c11, c12, and c44 constants as well as the shear constant C′ = (1/2)(c11 − c12) and the bulk modulus were tabulated between 4.2 and 290 K. The unusual temperature dependence of the shear constant c44 found in niobium was also observed in the alloys. The Debye temperatures were computed from the constants at 4.2 K.
22 citations
22 citations
20 citations
TL;DR: In this paper, various zirconium alloys have been exposed to iodine vapor at 300°C under static tensile stress and marked differences in their cracking behaviors were observed.
Abstract: Various zirconium alloys have been exposed to iodine vapor at 300°C under static tensile stress and marked differences in their cracking behaviors were observed. Some alloys that resisted cracking ...
20 citations
01 Jan 1974
Patent•
25 Oct 1974
TL;DR: For example, in this paper, the melting point of a powder having an excess of boron, carbon or nitrogen is assumed to be at least equal to that of the material of the container.
Abstract: For hydrostatically hot pressing bodies of borides, carbides or nitrides of titanium, zirconium or chromium from a powder having an excess of boron, carbon or nitrogen, the power is enclosed in a sealed container of a material which forms compounds with boron, carbon or nitrogen which have a melting point at least equal to that of the material of the container. Container materials may be for example metals from Group IVb of the Periodic System, particularly titanium and zirconium or their alloys in the case of titanium or chromium compounds and zirconium or zirconium base alloys in the case of zirconium compounds. This allows pressing at temperatures of up to 1700°-1800° C, which is high enough to cause bonding between the powder grains.
TL;DR: In this paper, Wolfenden and Farrell have reviewed the evidence and suggest that α-Zr has so far resisted void formation during neutron irradiation because of: (a) the absence of a dislocation (loop or tangle) structure and/or a low insoluble gas (e.g. helium) content.
Abstract: There has been much research and speculation recently on the nature of radiation induced defects in zirconium and its alloys, and in particular on the absence of voids at high fluences and temperatures in the range 0.3 to 0.5 T m (T m is the absolute melting temperature). Wolfenden and Farrell1 have reviewed the evidence and suggest that α-Zr has so far resisted void formation during neutron irradiation because of: (a) the absence of a dislocation (loop or tangle) structure and/or (b) a low insoluble gas (e.g. helium) content.
TL;DR: In this paper, a spouted bed constituted by a funnel carrying a charge of alumina microspheres, which were blown upward and held in dynamic suspension by a jet of the vapor and gases spouting from the funnel, was used for simultaneous deposition of carbon and zirconium from vapor produced by the reaction between methyl iodide vapor and ZIRconium sponge.
Abstract: Simultaneous deposition of carbon and zirconium from vapor produced by the reaction between methyl iodide vapor and zirconium sponge was studied with the application of a spouted bed constituted by a funnel carrying a charge of alumina microspheres, which were blown upward and held in dynamic suspension by a jet of the vapor and gases spouting from the funnel. The purpose of the experiment was to determine the conditions favorable for obtaining a coat of zirconium carbide-carbon alloy on the microspheres. Deposition of the vapor on the microspheres, leading to the formation of the carbon alloy coating, was found to take place at temperatures exceeding 1,100°C. The C/Zr ratio of the deposited coat was found to increase with deposition temperature. The hydrogen concentration in the spouting gas affected both the deposition yield and the chemical composition of the deposit. Repeated use of the sponge was found to impair its performance due to deactivation by premature deposition of carbon.
Patent•
11 Nov 1974TL;DR: In this article, a novel aqueous electrolytic activating solution and a method for electroplating zirconium alloys were disclosed, which is comprised of from about 10 to about 20 grams per liter of ammonium bifluoride (NH4 FHF) and from about 075 to 2 grams perliter of sulfuric acid (H2 SO4).
Abstract: A novel aqueous electrolytic activating solution and a method for electroplating zirconium and zirconium alloys are disclosed The novel aqueous electrolytic activating solution is comprised of from about 10 to about 20 grams per liter of ammonium bifluoride (NH4 FHF) and from about 075 to 2 grams per liter of sulfuric acid (H2 SO4)
TL;DR: In this article, Nb and Nb-1Zr alloy were irradiated to a fast neutron fluence of 25 × 1022 n/cm2 at 425°, 585°, and 790°C.
Abstract: Transmission electron microscnpe studies of Nb and Nb-1Zr alloy irradiated to a fast neutron fluence of 25 × 1022 n/cm2 at 425°, 585°, and 790°C revealed the presence of voids in Nb at all three irradiation temperatures and unusually large voids in the Nb-1Zr irradiated at 790°C No voids were observed in the Nb-1Zr irradiated at 425°C and 585°C The voids in Nb irradiated a t 425°C and 585°C were completely annealed after one hour at 1230°C (∼055 Tm,) whereas complete annealing of the voids in Nb irradiated at 790°C occurred after one hour at 1380°C (∼ 060 Tm) The anneals at 1230°C and 1380°C for the Nb-1Zr alloy irradiated at 790°C served to increase tlie void size and decrease the void concentration All evidence of the high concentration of small dislocation loops present in the Nb-lZr alloy irradiated at 425°C and 585°C was absent after annealing at 1230°C Microhiardness measurements of both materials indicated that the significant radiation induced strengthening of Nb and Nb-1Zr at 425
TL;DR: In this paper, a molten nitrate/nitrite eutectic has been used for studying the electrical characteristics of oxides on heat-treated Zr-25 wt % Nb in two conditions: quenched from 850°C or quench, cold-worked and aged at 500°C Oxides were grown in either water or steam, with or without oxygen, out-of-or in-reactor (fast flux 15 × 1013n · cm−2 · s−1) Tafel analysis of currentvoltage curves yielded oxide
TL;DR: In this paper, the distribution of residual stress in quadrants of Zr−2.5% Nb tube after flattening has been determined by measurement of the change in curvature during chemical thinning.
01 Jan 1974
01 Jan 1974
TL;DR: In this article, a molten nitrate/nitrite eutectic has been used for studying the electrical characteristics of irradiated oxides on crystal-bar zirconium and Zr-1.2 wt % Cr-0.08 wt% Fe grown under conditions producing accelerated oxidation at 295°C.
01 Jan 1974
01 Jan 1974
01 Jan 1974
TL;DR: In this article, the validity of a proposed transition theory was investigated by exposing a variety of Zr-alloys to 500°C superheated steam, and the experiment showed that the theory was valid for those alloys possessing intermetallic particles in the oxide.
01 Jan 1974