Deformation and annealing response of td-nickel chromium

Metallurgical and Materials Transactions A -     

Study of the sensitivity of different strians of the influenza A2 virus of rimantadine

The sensitivity of different influenza A2 (H3N2) virus strains to rimantadine in ovo was studied. The reference strains of influenza virus A/Hong Kong/1/68, A/England/42/72, A/Scotland/840/74 as well as new epidemic strains isolated in the USSR and Mongolia in 1974-1975 antigenically related to influenza A/Port Chalmers/1/73 virus were found to be sensitive to rimantadine.     

The Influence of Cobalt on the Microstructure of the Nickel-Base Superalloy MAR-M247

The influence of cobalt on the microstructure of MAR-M247, a cast nickel-base superalloy, was investigated. Nickel was substituted for Co to produce 0, 5, and the standard 10 pct Co versions of MAR-M247. The microstructures of the alloys were examined using optical and electron microscopy, X-ray diffraction, phase extraction, and differential thermal analysis. Samples were examined in as-cast, heat treated, long-time aged, and stress-rupture tested conditions. As Co was removed from MAR-M247, the γ′ volume fraction decreased, the mean γ′ particle size increased, the W and Ti concentrations in the γ′ increased, the Cr and Al concentrations in the γ phase decreased, and the amount of carbides increased. This increase in carbide precipitation caused a change from discrete grain boundary carbides to a grain boundary film as Co level decreased. M. V. NATHAL, formerly of Case Western Reserve University, R. D. MAIER, formerly of Case Western Reserve University,     

Zur Kinetik der Sauerstoffreduktion bei der Korrosion von Nickel in sauerstoffhaltiger Schwefelsäure

Kinetics of oxygen reduction during the corrosion of nickel in oxygen containing sulfuric acid The rate of oxygen reduction was determined for the corrosion of nickel in sulphuric acid containing oxygen. The rate depends upon the oxygen concentration and the acidity of the electrolyte. For a second order reaction with a preceding diffusion of oxygen and protons the values of the rate constant and the thickness of the diffusion layer were calculated. It could be shown that in In sulphuric acid the reduction rate is control led by the oxygen diffusion while in the weaker acids the rate controlling step is a proton transfer to the oxygen, adsorbed at the metal surface. Measurements of the dependance of the corrosion in In sulphuric and hydrochloride acid confirm these results.     

Time Horizon: Implications for Aggregate Scheduling Effectivness1

This performance of intuitive aggregate scheduling is compared with the scheduling performance of a mathematical model. A controlled experiment was designed to illustrate one scheduling problem characteristic which accounts for the superiority of model decisions over intuitive decisions. This relative superiority increases as the time-horizon complexity increases. The horizon complexity is a manifestation of the cost structure of the decision setting.     

The development of γ-γ′ lamellar structures in a nickel-base superalloy during elevated temperature mechanical testing

Changes in the morphology of the γ′ precipitate were examined during creep and tensile testing at temperatures between 927 and 1038 °C in [001]-oriented single crystals of a model Ni-Al-Mo-Ta superalloy. In this alloy, the γ′ particles link together to form lamellae, or rafts, which are aligned with their broad faces perpendicular to the applied tensile axis. The dimensions of the γ and γ′ phases were measured as the lamellar structure developed and were related to time and strain in an attempt to trace the changing γ-γ′ morphology. The results showed that directional coarsening of γ′ began during primary creep, and the attainment of a fully developed lamellar structure did not appear to be directly related to the onset of steady-state creep. The rate of directional coarsening during creep increased as the temperature was raised and also increased as the stress level was raised at a given testing temperature. The raft thickness remained equal to the initial γ′ size from the start of the creep test up through the onset of tertiary creep for all testing conditions. It was found that extensive rafts did not develop during the shorter testing times of the tensile tests, and that tensile testing of pre-rafted structures did not alter the morphology of the rafts. The overall behavior of the alloy was a clear indication of the stability of the finely-spaced γ-γ′ lamellar structure.