Transactions of the Japan Institute of Metals
Online ISSN : 2432-4701
Print ISSN : 0021-4434
ISSN-L : 0021-4434
Volume 15, Issue 6
Displaying 1-11 of 11 articles from this issue
  • Shigeyasu Koda
    1974 Volume 15 Issue 6 Pages 383-398
    Published: 1974
    Released on J-STAGE: June 01, 2007
    JOURNAL FREE ACCESS
    Download PDF (42228K)
  • Mitsunori Sato, Masayuki Hijikata, Ichiro Morimoto
    1974 Volume 15 Issue 6 Pages 399-407
    Published: 1974
    Released on J-STAGE: May 22, 2007
    JOURNAL FREE ACCESS
    Silver base contacts containing magnesium, aluminium, manganese, zirconium, lanthanum and cadmium oxides are prepared by internal oxidation. The material transfer or erosion characteristics of these contacts are investigated in the range of applied voltages from 40 to 212 V and currents from 6.4 to 80.1 A in direct current, alternating current and rectified full sinusoidal wave current circuits.
    The characteristics of the material transfer or erosion for switching contacts in direct current and alternating current can be clarified in many respects by a switching test of rectified full sinusoidal wave current. In the switching of rectified full sinusoidal wave current, the direction of the material transfer depends on the value of the testing current. In the range of lower current than the transition one the material transfer occurs in a direction from cathode to anode, and in the higher current range from anode to cathode. The direction of the material transfer and the amount of erosion are affected remarkably by the kind of containing oxides, and particularly by the materials of the electrode in which erosion occurs. In the range of material transfer from cathode to anode in direct current and rectified full sinusoidal wave current, the amount of cathode erosion is approximately proportional to the arc energy in contact breaking at a constant applied voltage. Moreover, the ratio of the amount of material transfer to the arc energy varies with the oxides contained.
    Download PDF (22308K)
  • Mitsunori Sato, Masayuki Hijikata, Ichiro Morimoto
    1974 Volume 15 Issue 6 Pages 408-412
    Published: 1974
    Released on J-STAGE: May 22, 2007
    JOURNAL FREE ACCESS
    Four silver base alloys containing two kinds of oxide, namely, manganese and zirconium oxides, magnesium and zirconium oxides, magnesium and lanthanum oxides, and lanthanum and zirconium oxides, are prepared by the internal oxidation in air at 650°C. The characteristics of the erosion resistance, the welding adhesion resistance and the contact resistance as the electrical contact have been investigated with them under an applied voltage of 100 V and amperage from 10 to 50 A in alternating current.
    The coexistence of zirconium oxide with the others is very effective for improving the welding adhesion resistance. Comparing with the characteristics of silver-12 wt% cadmium oxide contacts which are generally used, the contacts containing lanthanum and zirconium oxides (0.40 at% La and 0.49 at% Zr) have the higher welding adhesion resistance and a little lower erosion resistance, and those containing magnesium and zirconium oxides (0.49 at% Mg and 0.50 at% Zr) have almost the same erosion resistance and welding adhesion resistance. Furthermore, these contacts are comparable in contact resistance to each other. On the other hand, the erosion resistance of the silver base contacts containing manganese and zirconium oxides (2.0 at% Mn and 0.96 at% Zr), magnesium and zirconium oxides (0.49 at% Mg and 0.50 at% Zr) and magnesium and lanthanum oxides (0.49 at% Mg and 0.36 at% La) is improved in the high current region, because the dependence of the amount of erosion on the testing current is less than that of other contacts.
    Download PDF (15213K)
  • Kazutaka Kawamura
    1974 Volume 15 Issue 6 Pages 413-416
    Published: 1974
    Released on J-STAGE: May 22, 2007
    JOURNAL FREE ACCESS
    The diffusion coefficients of silver ion in molten lithium nitrate-cesium nitrate and potassium nitrate-cesium nitrate mixtures have been determined by chronopotentiometry in the temperature range from 260 to 380°C.
    The diffusion coefficient of silver ion in lithium nitrate-cesium nitrate mixture increases with the increase of concentration of cesium nitrate from 0 to 20 mol% and decreases with the increase of concentration of cesium nitrate from 20 to 100 mol%, indicating a maximum value at 20 mol% of cesium nitrate. The diffusion coefficient of silver ion in the potassium nitrate-cesium nitrate mixture decreases monotonously with the increase of the concentration of cesium nitrate.
    The activation energy for diffusion of silver ion has a minimum value at about 20 mol% of cesium nitrate in the lithium nitrate-cesium nitrate mixture and increases monotonously with the increase of concentration of cesium nitrate in the potassium nitrate-cesium nitrate mixture.
    By comparing the determined diffusion coefficients of silver ion in alkali nitrate mixtures with those in pure alkali nitrates, it is found that the circumstances around the silver ion diffused at the concentration of about 20 mol% of cesium nitrate in the lithium nitrate-cesium nitrate mixture approach that in pure sodium nitrate. Such a finding may explain the above concentration dependence of the activation energy for diffusion of silver ion in the lithium nitrate-cesium nitrate and potassium nitrate-cesium nitrate mixtures.
    Download PDF (10835K)
  • Akira Okada, Haruo Mitsuji, Hitoshi Nakaé
    1974 Volume 15 Issue 6 Pages 417-422
    Published: 1974
    Released on J-STAGE: June 01, 2007
    JOURNAL FREE ACCESS
    The variation of the energy release during the recrystallization process and the texture change were investigated by differential calorimetric analysis and X-ray texture measurements of Cu sheets cold rolled by various rolling procedures. Copper sheets of 2 mm thick were at first rolled in one direction (primary rolling), then rolled to a final thickness of 0.1 mm in the transverse direction (secondary rolling). The amount of deformation in the secondary rolling was 9 to 90% reductions in thickness. On slight secondary reductions less than 20%, the rolling texture changed little and the recrystallization texture showed a well-developed cube texture, whereas, the activation energy for the recrystallization decreased from 74 to 62 kcal/mol. For the specimens secondly rolled by 9% to 75%, the activation energy had an almost constant value of 62 kcal/mol. The condition for the “intrinsic” growth of the cube oriented grain would be easily collapsed, then only a slight reduction of secondary rolling affected the growth behavior of the cube grain. The predominance of the cube grain growth presumably originated from the configuration of the boundary regions between the cube component and the matrix in the deformed materials. However, no difference in the recrystallization behavior was found among the specimens by electron microscopy.
    Download PDF (16308K)
  • Hakaru Masumoto, Naoji Nakamura
    1974 Volume 15 Issue 6 Pages 423-426
    Published: 1974
    Released on J-STAGE: June 01, 2007
    JOURNAL FREE ACCESS
    The temperature coefficient of delay time, αD, at 0 to 40°C and the maximum gradient of magnetostriction in the applied magnetic field, (dλ⁄dH)m, at room temperature have been measured with the annealed alloys in the Co–Fe–Cr system, the Co–Fe–Cr-16.7% Ni system and the Co–Fe–Cr-28.6% Ni system. It has been found that in Co-31.0% Fe-9.0% Cr alloy the αD has such a small value as −0.42×10−5. The (dλ⁄dH)m is 0.36×10−6/Oe which is comparable with the absolute value of −0.39×10−6/Oe in nickel. The αD, for Co-37.8% Fe-4.3% Cr-16.7% Ni alloy also shows a very small value of −0.07×10−5, while its (dλ⁄dH)m shows a very large value of 0.80×10−6/Oe which is about two times greater than the absolute value of nickel and five times greater than that of Ni-Span C. And Co-50.0% Fe-2.4% Cr-28.6% Ni alloy has a small value of −0.21×10−5 for αD and 0.19×10−6/Oe for (dλ⁄dH)m which is about half of the absolute value for nickel. Among these alloys, a Co-37.8% Fe-4.3% Cr-16.7% Ni alloy not only exhibit excellent characteristics of the magnetostrictive delay line but also can easily be cold worked. Therefore, the alloy seems to be a material suitable for the delay line.
    Download PDF (8680K)
  • Hakaru Masumoto, Showhachi Sawaya, Michio Kikuchi
    1974 Volume 15 Issue 6 Pages 427-431
    Published: 1974
    Released on J-STAGE: May 22, 2007
    JOURNAL FREE ACCESS
    Measurements of Young’s modulus at −150∼400°C and of rigidity modulus, thermal expansion and hardness at room temperature have been carried out with Mn–Ni–Mo alloys subjected to cold working and heat treatment. The ternary alloys slowly cooled after annealing for 1 hr at 950°C show an anomalous temperature dependence to be associated with the antiferromagnetic\ ightleftarrowsparamagnetic transformation. Young’s modulus at room temperature do not show any significant variations in both the cold worked and annealed states, but this value tends to increase with increasing manganese or molybdenum concentration. The temperature coefficient of Young’s modulus show a wide variation from a negative to a positive value by annealing, water quenching, cold working, and reheating after water quenching or cold working, with a strong composition dependence. The variations in rigidity modulus and its temperature coefficient with heat treatment, cold reduction rate and composition are very similar to those in Young’s modulus and its temperature coefficient. The vickers hardness of the alloys varies in a complex manner between about 100 to 650 by the various treatments and compositions. The corrosion resistivity of Mn–Ni–Mo alloys is relatively good.
    Download PDF (11463K)
  • R. V. Patil, G. P. Tiwari
    1974 Volume 15 Issue 6 Pages 432-434
    Published: 1974
    Released on J-STAGE: May 22, 2007
    JOURNAL FREE ACCESS
    The paper discusses the correlation of the diffusion data with cohesive energy. The free energy for self diffusion of metals at the melting point is shown to be a linear function of their cohesive energies. In the case of solute diffusion, it is shown that the excess free energy for impurity-diffusion at the melting point is similarly related to the partical molar free energy of the solute atom as determined on the basis of the Hildebrand’s regular solution model.
    Download PDF (5918K)
  • Kyôji Nakanishi, Hideji Suzuki
    1974 Volume 15 Issue 6 Pages 435-440
    Published: 1974
    Released on J-STAGE: May 22, 2007
    JOURNAL FREE ACCESS
    Grain size dependence of the yield stress in polycrystalline copper-aluminum and copper-nickel alloys is measured at 77, 194 and 293°K. It is found that the Hall-Petch relation is valid for these materials. The Petch slope ky is nearly independent of the temperature, but increases with increasing solute concentration. In copper-aluminum alloys the increase in ky is nearly proportional to the square root of the solute concentration, while in copper-nickel alloys it is proportional to the concentration itself. The concentration dependence of ky, in Cu–Al alloys is considerably larger than that in Cu–Ni alloys. None of previously proposed theories on the Petch slope can explain these results. The experimental results will be compared with the calculation in the following paper.
    Download PDF (14325K)
  • Yuji Ikeda, Kazuyoshi Nii, Gérard Béranger, Paul Lacombe
    1974 Volume 15 Issue 6 Pages 441-446
    Published: 1974
    Released on J-STAGE: June 01, 2007
    JOURNAL FREE ACCESS
    The cation tracer diffusion coefficient D and the electric conductivity σ in NiO were measured as a function of temperature and oxygen partial pressure PO2. Polycrystalline NiO sample was prepared by oxidation of zone refined nickel platelets in an oxygen stream. For conductivity measurement single crystal was also used. It was found that σ was proportional to PO21⁄4∼1⁄5, regardless of the method of sample preparation. This suggests strongly the superiority in concentration of the singly ionized vacancy V′. On the other hand, D depended very slightly on PO2, much less than the 1/4 power. This discrepancy of the PO2 dependence of σ and D can be successfully explained by the following assumption: The cation diffusion takes place in a dual manner, through singly ionized vacancies V′ and through doubly ionized vacancies V″. The contribution of V′ to the diffusion is predominant in the higher PO2 region because of its high concentration, whereas that of V″ is more important in the lower PO3 region because of its large mobility.
    Download PDF (13597K)
  • Iwao Katayama, Shigeo Igi, Zensaku Kozuka
    1974 Volume 15 Issue 6 Pages 447-453
    Published: 1974
    Released on J-STAGE: June 01, 2007
    JOURNAL FREE ACCESS
    E.M.F. of a galvanic cell with the solid electrolyte (ZrO2+CaO) was measured to determine the activities of gallium in the temperature range of 800∼1000°C and the composition range of 5∼58 at% Ga for solid Ni–Ga alloys, and thermodynamic functions were derived from the results. The cells used were as follows;
    Pt, Re, Ga, Ga2O3/ZrO2(+CaO)/Fe, FexO, Pt
    Pt, Re, (Ni–Ga), Ga2O3/ZrO2(+CaO)/Fe, FexO, Pt
    Activities of both components showed large negative deviations from Raoult’s law; Activity change with composition in a nickel-rich α-solid solution and in the α′(Ni3Ga)-phase were small, but very large in the β(NiGa)-phase. Relative integral molar free energies of formation showed minimum values at the stoichiometric composition NiGa. Integral enthalpies and entropies of formation showed relatively large negative values.
    Download PDF (15850K)
feedback
Top