Chargeability of nickel electrodes studied by optical microscopy
Some of the operational characteristics of some nickel hydrogen cells are explained. Some strange capacity excursions with cycling were seen.
Dyer, C. K.↗
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Nickel-hydrogen flight relay and cell shorting test
A relay used on a standard flight configuration of nickel-hydrogen cells is discussed.
Stadnick, S. J.↗
Nickel system manufacturing update
The electrochemical positive electrode was used in nickel hydrogen for six or seven years with very good results, primarily because of the dimensional stability and the high electrical utilization of the active material.
Miller, L.↗
Coupling between the nickel-carbon and carbon-oxygen stretch motion in NiCO
Linear-combination-of-Gaussian-type-orbital (LCGTO) X-alpha calculations are performed on NiCO for various linear Ni-CO and NiC-O bond distances. The basis sets used are moderately large, approximately double zeta, and thus are fairly accurate within the X-alpha approximation. The electronic structure and equilibrium bond distances are consistent with recent CI calculations, indicating a much stronger Ni-CO bond than occurs in Ni(CO)4. The calculations agree to within 100/cm with the experimentally observed NiC-O stretch frequency. The Ni-CO stretch is predicted to occur at 656/cm, although at an intensity that is 640 times less. Compared with experimental results for CO adsorbed on single crystal Ni(100), the computed vibrational frequencies and intensities are less appropriate than the relevant experimental values for Ni(CO)4. This is interpreted to mean that an accurate description of the electronic structure of the nickel atom participating directly in the surface bond requires proper accounting of the bonds to its other nearest neighbors.
Dunlap, B. I.↗
Screenable all-metal solar cell electrodes of nickel and copper
Screenable thick film solar cell electrodes are made using the all-metal electrode system, which eliminates the commonly used glass frit and substitutes an oxide scavenger such as silver fluoride. The low temperature firing copper metal systems give good results on solar cells obtaining cell efficiencies of 13% AM1, and adhering sintered structures are demonstrated with nickel systems. The potential effect of copper upon cell performance at elevated temperatures over long periods of time is determined, and it is found that the formation of a copper-silicon eutectic at 550 C produces needle-like structures with broad bases on the silicon, extending into and occasionally through the metallization layer.
Ross, B.↗
Isotopes of cosmic ray elements from neon to nickel
Results obtained from a balloon exposure of a cosmic ray detector flown in 1977 are reported. The charge resolution ranged from 0.19 to 0.21 charge units between neon and nickel and the mass resolution for nuclei stopped in the emulsions ranged from 0.40 to 0.70 amu for A between 20 and 60 amu. This was enough to correctly identify almost all nuclei, but not to uniquely resolve neighboring mass peaks. Both Ne and Mg show evidence for neutron enrichment relative to the solar system abundance. Si and S are consistent with solar abundances, while Ar has no significant source abundances. P, Cl and K have essentially no primary component and the isotopic distribution observed is quite consistent with that expected from propagation. An excess of Ca-44 at the source is shown, indicating high metallicity in the source. The abundance of Fe-58 is nine percent or less, and Ni shows a one-to-one ratio for Ni-58 to 60, implying intermediate metallicity.
Waddington, C. J.↗
Fatigue and creep-fatigue deformation of several nickel-base superalloys at 650 C
Transmission electron microscopy has been used to study the bulk deformation characteristics of seven nickel-base superalloys tested in fatigue and creep-fatigue at 650 C. The alloys were Waspalloy, HIP Astroloy, H plus F Astroloy, H plus F Rene 95, IN 100, MERL 76, and NASA IIB-7. The amount of bulk deformation observed in all the alloys was low. In tests with inelastic strain amplitudes less than about 0.003, only some grains exhibited yielding and the majority of those had the 110 line near the tensile axis. Deformation occurred on octahedral systems for all of the alloys except MERL 76 which also showed abundant primary cube slip. Creep-fatigue cycling occasionally produced extended faults between partial dislocations, but otherwise deformation was much the same as for fatigue cycling.
Miner, R. V.↗
Hot Microfissuring in Nickel Alloy
Experiments in intergranular cracking of nickel alloy near solidus temperature discussed in contractor report. Purpose of investigation development of schedule for welding, casting, forging, or other processing of alloy without causing microfissuring.
Thompson, R. G.↗
Role of cobalt in nickel base superalloys
The effect of cobalt or substituting for cobalt on the mechanical properties of nickel-based superalloys is discussed. Waspaloy, UDIMET 700, and NIMONIC 115, which are representative of Ni-Cr-Co-Al-Ti-Mo superalloys having different gamma prime contents which are strengthened by a heavily alloyed matrix, coherent gamma prime precipitates, and carbides at the grain boundaries. Microstructure and in situ and extracted phase STEM micro-analysis were used to evaluate the three alloys.
Jarrett, R.↗
Pore size engineering applied to the design of separators for nickel-hydrogen cells and batteries
Pore size engineering in starved alkaline multiplate cells involves adopting techniques to widen the volume tolerance of individual cells. Separators with appropriate pore size distributions and wettability characteristics (capillary pressure considerations) to have wider volume tolerances and an ability to resist dimensional changes in the electrodes were designed. The separators studied for potential use in nickel-hydrogen cells consist of polymeric membranes as well as inorganic microporous mats. In addition to standard measurements, the resistance and distribution of electrolyte as a function of total cell electrolyte content were determined. New composite separators consisting of fibers, particles and/or binders deposited on Zircar cloth were developed in order to engineer the proper capillary pressure characteristics in the separator. These asymmetric separators were prepared from a variety of fibers, particles and binders.
Abbey, K. M.↗
Cycle life test and failure model of nickel-hydrogen cells
Six ampere hour individual pressure vessel nickel hydrogen cells were charge/discharge cycled to failure. Failure as used here is defined to occur when the end of discharge voltage degraded to 0.9 volts. They were cycled under a low earth orbit cycle regime to a deep depth of discharge (80 percent of rated ampere hour capacity). Both cell designs were fabricated by the same manufacturer and represent current state of the art. A failure model was advanced which suggests both cell designs have inadequate volume tolerance characteristics. The limited existing data base at a deep depth of discharge (DOD) was expanded. Two cells of each design were cycled. One COMSAT cell failed at cycle 1712 and the other failed at cycle 1875. For the Air Force/Hughes cells, one cell failed at cycle 2250 and the other failed at cycle 2638. All cells, of both designs, failed due to low end of discharge voltage (0.9 volts). No cell failed due to electrical shorts. After cell failure, three different reconditioning tests (deep discharge, physical reorientation, and open circuit voltage stand) were conducted on all cells of each design. A fourth reconditioning test (electrolyte addition) was conducted on one cell of each design. In addition post cycle cell teardown and failure analysis were performed on the one cell of each design which did not have electrolyte added after failure.
Smithrick, J. J.↗
Test results of a ten cell bipolar nickel-hydrogen battery
A ten cell bipolar nickel hydrogen 6.5 ampere-hour battery demonstrated over 2000 low Earth orbit cycles at an 80 percent depth-of-discharge. Charge/discharge cyclic ampere-hour and watt-hour efficiencies of 88 and 76 percent, respectively, observed. Peak power capability was determined at 1.1 kW. A 10C discharge rate yields 83 percent of the nominal stark capacity to the 1.0 volt cut off in just under 6 minutes.
Cataldo, R. L.↗
Understanding the roles of the strategic element cobalt in nickel base superalloys
The United States imports over 90% of its cobalt, chromium, columbium, and tantalum, all key elements in high temperature nickel base superalloys for aircraft gas turbine disks and airfoils. Research progress in understanding the roles of cobalt and some possible substitutes effects on microstructure, mechanical properties, and environmental resistance of turbine alloys is discussed.
Stephens, J. R.↗
Reconditioning and the nickel electrode
This effects of reconditioning on the performance of NiCd batteries are reviewed. These effects are correlated with cell experiments and individual electrode investigations. The effects of reconditioning on the positive electrode performance are found to be significant. A mechanism is proposed that rationalizes the operation of the nickel electrode and suggests that reconditioning minimizes depth of discharge stress during use and maintains uniformity of the active material.
Zimmerman, A. H.↗
Canadian experience with nickel cadmium systems
The Defense Research Establishment Ottawa (DREO) has been studying the nickel-cadmium system, both vented and sealed, since the early 1950's. Reasonable success has been achieved in a wide variety of applications covering: military vehicle use under Arctic conditions; high performance military aircraft; manpacked communications sets; remote standby power and small portable instrumentation. Early studies on the vented system for high rate vehicle and aircraft cranking applications proved useful in later studies on the sealed NiCd system. This was especially true in the areas of plate loading and electrolyte composition. To achieve high rate cranking currents of 20C to 30C, it was necessary to have light to moderate plate loadings, a large reactive surface area, and electrolyte of optimum conductivity. DREO undertook some fundamental studies to understand the system from the inside out rather than test cells from the outside and then analyze their components. The conclusions of these studies were incorporated into the Procurement Specification for Ni-Cd cells ISISA Spec S615-P-2. A brief comment will be made on the choice of cell design and how some of the factors of cell manufacture could affect cell performance.
Lackner, J. L.↗
Fine, nickel-poor Fe-Ni grains in the olivine of unequilibrated ordinary chondrites
Nickel-poor Fe-Ni grains smaller than 2.0 microns are common inclusions in ordinary, unequilibrated chondrites' porphyritic chondrule olivine, where the olivine grains seem to be relicts that survived chondrule formation without melting. This 'dusty' metal, whose most common occurrence is in the core of olivine grains having clear, Fe-poor rims, appears to be the product of the in situ reduction of FeO from the host olivine, with H2 or carbonaceous matter being the most likely reductants. H2 may have been implanted by solar wind or solar flare irradiation, but this requires the dissipation of nebular gas before the end of the chondrule formation process. Carbonaceous matter may have been implanted by shock. The large relict olivine grains may be nebular condensates or fragments broken from earlier chondrule generations.
Rambaldi, E. R.↗
Requirements of constitutive models for two nickel-base superalloys
The constitutive behavior of two nickel-base superalloys, Rene '80 and Inconel 718, utilized in gas turbine blade and disk components, respectively, is presented. In turbine blade applications, the high homologous temperatures result in strain-rate effects dominating behavior. In turbine disks, the temperatures are cooler so that mean stress effects become important. The impact of these two variables on the overall crack initiation lifetime and analysis methodology is discussed.
Laflen, J. H.↗
Metallurgical instabilities during the high temperature low cycle fatigue of nickel-base superalloys
An investigation is made of the microstructural instabilities that affect the high temperature low cycle fatigue (LCF) life of nickel-base superalloys. Crack initiation processes, provoked by the formation of carbides and the coarsening of the grains of the material at high temperatures are discussed. Experimental results are examined, and it is concluded that LCF behavior can be understood more fully only if details of the material and its dynamic behavior at high temperatures are considered. The effects of high stress, dislocation debris, and increasing environmental damage on the life of the alloy are discussed.
Antolovich, S. D.↗