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Here, an iron-based amorphous metal with good corrosion resistance and a high absorption cross section for thermal neutrons has been developed and is reported here. This amorphous alloy has the approximate formula Fe_49.7Cr_17.7Mn_1.9Mo_7.4W_1.6B_15.2C_3.8Si_2.4 and is known as SAM2X5. Chromium, molybdenum, and tungsten were added to provide corrosion resistance, while boron was added to promote glass formation and the absorption of thermal neutrons. Since this amorphous metal has a higher boron content than conventional borated stainless steels, it provides the nuclear engineer with design advantages for criticality control structures with enhanced safety. While melt-spun ribbons with limited practical applications were initiallymore » produced, large quantities (several tons) of gas-atomized powder have now been produced on an industrial scale, and applied as thermal-spray coatings on prototypical half-scale spent-nuclear-fuel containers and neutron-absorbing baskets. These prototypes and other SAM2X5 samples have undergone a variety of corrosion testing, including both salt-fog and long-term immersion testing. Modes and rates of corrosion have been determined in various relevant environments and are reported here. While these coatings have less corrosion resistance than melt-spun ribbons and optimized coatings produced in the laboratory, substantial corrosion resistance has been achieved.« less

Oxy-fuel combustion is based on burning fossil fuels in a mixture of recirculated flue gas and oxygen, rather than in air. An optimized oxy-combustion power plant will have ultra-low emissions since the flue gas that results from oxy-fuel combustion consists almost entirely of CO2 and water vapor. Once the water vapor is condensed, it is relatively easy to sequester the CO2 so that it does not escape into the atmosphere. A variety of laboratory tests comparing air-firing to oxy-firing conditions, and tests examining specific simpler combinations of oxidants, were conducted at 650-700 C. Alloys studied included model Fe-Cr and Ni-Crmore » alloys, commercial ferritic steels, austenitic steels, and nickel base superalloys. Furthermore, the observed corrosion behavior shows accelerated corrosion even with sulfate additions that remain solid at the tested temperatures, encapsulation of ash components in outer iron oxide scales, and a differentiation between oxy-fuel combustion flue gas recirculation choices.« less

The magnetocaloric properties of the (Er{sub 1-x}Tb{sub x})Al{sub 2} alloys have been evaluated by magnetization and heat capacity measurements. It is shown that by partial substitution of Er by Tb the ferromagnetic ordering temperature of (Er{sub 1-x}Tb{sub x})Al{sub 2} can be tuned over a wide range of temperatures, that is from 13 K (ErAl{sub 2}) to 110 K (TbAl{sub 2}). Over the entire temperature range the alloy system exhibits large magnetocaloric effect. For a field change of 5 T, the observed magnetic entropy changes peaks from -18 J/kg K (x = 0.20) to -12 J/kg K (x = 0.90). Themore » adiabatic temperature changes measured for selected alloys in the series show a maximum value of 6 K when the magnetic field is changed from 0 to 5 T.« less

In this study, an overview of the High-Performance Corrosion-Resistant Materials (HPCRM) Program, which was cosponsored by the Defense Advanced Research Projects Agency (DARPA) Defense Sciences Office (DSO) and the U.S. Department of Energy (DOE) Office of Civilian and Radioactive Waste Management (OCRWM), is discussed. Programmatic investigations have included a broad range of topics: alloy design and composition, materials synthesis, thermal stability, corrosion resistance, environmental cracking, mechanical properties, damage tolerance, radiation effects, and important potential applications. Amorphous alloys identified as SAM2X5 (Fe_49.7Cr_17.7Mn_1.9Mo_7.4W_1.6B_15.2C_3.8Si_2.4) and SAM1651 (Fe₄₈Mo₁₄Cr₁₅Y₂C₁₅B₆) have been produced as meltspun ribbons (MSRs), dropcast ingots, and thermal-spray coatings. Chromium (Cr), molybdenum (Mo),more » and tungsten (W) additions provided corrosion resistance, while boron (B) enabled glass formation. Earlier electrochemical studies of MSRs and ingots of these amorphous alloys demonstrated outstanding passive film stability. More recently, thermal-spray coatings of these amorphous alloys have been made and subjected to long-term salt-fog and immersion tests; good corrosion resistance has been observed during salt-fog testing. Corrosion rates were measured in situ with linear polarization, while the open-circuit corrosion potentials (OCPs) were simultaneously monitored; reasonably good performance was observed. The sensitivity of these measurements to electrolyte composition and temperature was determined. The high boron content of this particular amorphous metal makes this amorphous alloy an effective neutron absorber and suitable for criticality-control applications. In general, the corrosion resistance of such iron-based amorphous metals is maintained at operating temperatures up to the glass transition temperature. These materials are much harder than conventional stainless steel and Ni-based materials, and are proving to have excellent wear properties, sufficient to warrant their use in earth excavation, drilling, and tunnel-boring applications. Large areas have been successfully coated with these materials, with thicknesses of approximately 1 cm. The observed corrosion resistance may enable applications of importance in industries such as oil and gas production, refining, nuclear power generation, shipping, etc.« less

The solubilities of the transition metals from scandium to nickel, inclusive, in liquid cadmium were determined by sampling saturated solutions. At 400° C these solubilities (in ppm) are: Sc, 8200; Ti, 150; V, <0.2; Cr, 2; Mn, 2500; Fe, 1; Co, 22; Ni, 12000. Relative partial molal enthalpies and excess partial molal entropies at inflnite dilution for the solutes Cr, Mn, Fe, and Co are compared with similar data for the post-transition metals. Three new intermetallic phases, ScCd₃, TiCd, and Ti₂Cd, encountered in the course of this work, are reported. (auth)

Thermodynamic stepwise equilibrium formation constants are given for the reaction in aqueous solution of the acetylacetonate ion with Cu²⁺, Be²⁺, UO₂²⁺, Ni²⁺, Co²⁺, Zn²⁺, Mn²⁺, Cd²⁺, Mg²⁺ and Ce³⁺ at 10, 20 and 40°. Constants at 30° have been given in previous publications. Values of the thermodynamic quantities, ΔH, ΔS and ΔF are given over the temperature range 10 to 40° for the formation of the first complex, MCh^(n-1)+, in each case (except UO₂²⁺), of MCh₂^(n-2)+ in each case (except Zn²⁺ and Cd²⁺), and of MCh₃- in the case of Ni²⁺. Values for these thermodynamic quantities are also given formore » the dissociation of acetylacetone over the above temperature range. The significance of the values obtained is discussed in the light of the reactions involved. Comparisons are made with other thermodynamic values in the literature involving several of these same ions with other ligand types.« less

Cylinders of iron, zinc, and cadmium were rotated in a highly corrosive solution of acid containing nitrate ion as a depolarizer, as described previously. Three kinds of inhibitors were added to the solution : (a) dichromate ion plus complexing or chelating agents for metal ions; (b) a wetting or emulsifying agent which is strongly adsorbed; and (c) a reagent which forms a very insoluble precipitate with ferrous and ferric ions. Measurements of the effectiveness of these inhibitors are given.

A coprecipitation study required a rapid and accurate method for the determination of small quantities of tin. The reaction between tin (IV) and hematoxylin at pH 0.8 produces a red color with an absorption maximum at approximately 515 mu for 0.1 to 14 milligrams of tin per liter. Beer's Law is not completely followed but the curve obtained is reproducible and easily prepared. The effects due to the presence of other ions have been noted. Analyses of some standard alloy samples indicate an error of the order of ±1. The method presents possibilities for the analysis of tin in non-ferrousmore » materials. It should also be useful for the determination of tin in trace quantities as in water analysis.« less

In dilute hydrochloric acid with excess potassium nitrate as a depolarizer, iron, zinc, and cadmium dissolve at, or nearly at, a maximum rate controlled by the rate of convection and the speed of diffusion of the hydrogen ion. The dissolution rates of these metals may be reduced to comparatively small values by addition of dichromate, molybdate, or tungstate. With very pure iron and zinc the dissolution rate in the presence of dichromate can be reduced still more by the addition of a soluble fluoride. While none of the solutions used are highly protective, the experiments described arc of aid inmore » interpreting the mechanism of inhibition.« less

Here the reaction of fluorine with cadmium, cadmium oxide, cadmium chloride and cadmium sulfide has been investigated. Cadmium fluoride is the only non-volatile product formed. The crystal structure of cadmium fluoride has been checked and a more precise lattice constant determined; a₀ = 5.3880 ± 0.0005 Å. The reported experimental density values have been corrected; d = 6.33 ± 0.06 g./cc. The melting point of cadmium fluoride is 1049 ± 2°.