All issues
Volume 30, Issue 2
Displaying 1-6 of 6 articles from this issue
- |<
- <
- 1
- >
- >|
-
Application of Helium Ion Back ScatteringYoshiro Iwama1983 Volume 30 Issue 2 Pages 41-47
Published: February 25, 1983
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSIf a double layer thin film composed of different atomic spieces is annealed, an intermetallic phase may easily be formed. The formation process of the phase can be successively investigated using such a thin film diffusion couple; this approach is proposed to be called "thin film metallurgy". Helium ion back scattering experiment, which provides an important tool in the thin film metallurgy, is briefly introduced. As an instructive example, a formation process of MnBi thin film is described.View full abstractDownload PDF (3253K) -
Preparation by a Wet Method and Ionic Distribution of Transition Metal-substituted Hausmanite SpinelNaoichi Yamamoto, Shinji Kawano, Norio Achiwa, Shin-nosuke Higashi1983 Volume 30 Issue 2 Pages 48-54
Published: February 25, 1983
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSA wet method was applied to prepare a spinel type MMn2O4 (M=Mn, Mg, Zn, Cu, Fe, Co, Ni and Cd) in alkaline water solution below 100°C. When M is Mn, Zn or Co, a stoichiometric spinel is prepared. When M is Mg, Fe or Cd, a partially substituted spinel is obtainable, and chemical compositions of the spinels which have the maximum foreign atom contents are given by Mg0.2Mn2.8O4, Fe0.4Mn2.6O4 and Cd0.6Mn2.4O4, respectively. Cu and Ni-substituted spinels are not obtainable by the method. Neutron diffraction measurements show that ZnMn2O4 and CoMn2O4 have their ionic distributions of (Zn2+) [Mn2]O4 and (Co0.842+Mn0.162+)[Co0.16II+Mn1.843+]O4, respectively.View full abstractDownload PDF (1713K) -
Hiroshi Kuno, Kosuke Fukutani1983 Volume 30 Issue 2 Pages 55-61
Published: February 25, 1983
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSMnLiZn ferrite granules of different strength were prepared by changing either amount of binder or kneading time. Rates of compaction of these granules in a die were expressed by following two equations.
First step, ε=k'logt+k0(1)
and second step, log(1+k1logε)=k2t+k3(2).
Relations among the strength of granules and coefficients in equations were discussed. Not only the strength but also methods of preparation were effective for the change in values of coefficients. Effects of size of granule on these values of coefficients and sintering behavior of compacts were also studied.View full abstractDownload PDF (414K) -
Sintering of Cu-6.8%Al Alloy from (Cu)-(Cu-Al)-mixed-powder CompactsYasuhiko Hashimoto, Shinichiro Ohmaori, Koichiro Kohyama, Masato Kikuk ...1983 Volume 30 Issue 2 Pages 62-69
Published: February 25, 1983
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSGreen compacts containing 6.8 masso%Al prepared from the mixture of Cu and Cu-11mass% Alalloy powders were heated under various conditions. Sintering proceeded more readily than thatfor the use of previously reported prealloyed powder compacts, but the properties of sintered compacts were considerably influenced by raw powders and heating conditions such as the oxygen content of the Cu powder, the oxygen potential of the atmosphere, and heating rate.
Sintered compacts having high strength, high ductility and high specific density were obtained when the green compacts prepared from low oxygen powders and embedded in graphite powder were heated rapidly to about 1270K and held at this temperature for 4-7 ks in a reduced (CO) pressure less than 0.03 Pa.
The use of Cu-Al powders of high Al content as the raw powders was effective for acceleration of sintering reaction, but it did not improve the strengths and the specific densities of the sintered compacts.View full abstractDownload PDF (6977K) -
Hiroshi Nagai, Makoto Okabayashi, Takeshi Fujikawa, Kei-ichiro Shoji1983 Volume 30 Issue 2 Pages 70-74
Published: February 25, 1983
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThe isothermal oxidation behavior of sintered Ni-20Cr alloys with 0.7 mass% dispersion of various reactive metal oxides (Y2O3, La2O3, Gd2O3, Al2O3, ZrO2, TiO2, SiO2, MgO, Ta2O5 and Cr2O3) was investigated in air at 1373 and 1473 K.
It was found that the oxidation rate was significantly dependent on the type of the dispersed oxides. The dispersion of MgO, ZrO2, SiO2 and Cr2O3 increased the oxidation rate, while the dispersion of La2O3 and Gd2O3 excellently reduced the oxidation rate of the sintered Ni-20Cr alloy. The oxidation rate of the sintered Ni-20Cr alloy was not reduced by the dispersion of Y2O3, which excellently reduced the oxidation rate of the sintered Fe-2OCr alloy. The scale adhesion was also markedly dependent on the type of the dispersed oxides. The dispersions ofLa2O3 and Gd2O3 excellently improved the scale adhesion.
The results of EPMA observation and X-ray diffraction for the scale revealed that the scale generally consisted of inner Cr2O3 scale and outer NiO scale. There was a general tendency that the thickness of the outer NO scale was larger on the alloys which showed larger mass gain. A thin Cr2O3 scale without outer NiO scale was maintained stably on the alloys with La2O3 and Gd2O3. It may be concluded from these results that the additions of La2O3 and Gd2O3 suppress outward migration of Ni ions through the Cr2O3 scale.View full abstractDownload PDF (1678K) -
Osamu Iwatsu, Teruhisa Watanabe1983 Volume 30 Issue 2 Pages 75-79
Published: February 25, 1983
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSThe driving performance tests of sintered iron-(5-40) %lead-3%copper and iron-(10-30)% lead porous bearings produced by a low-temperature sintering at 900°C were carried out. The results were compared with conventional iron, iron-copper and bronze porous bearings.
The results obtained were as follows:
1) The coefficient of friction of the iron-lead-copper bearing having lead contents of over 10% did not rise even at a fairly high pressure, but only showed an abnormal wear at a critical pressure. The critical pressure of iron-20% lead-3% copper bearing was highest.
2) The critical pressures for the abnormal wear of iron-lead bearings were lower than those of the iron-lead-copper bearings. Therefore, the addition of copper is also necessary for increasing the driving performance as well as increasing the strength of the iron-lead-copper bearing.
3) On comparison of the driving performance among the conventional iron, iron-copper and bronze bearing, the level of coefficient of friction of iron-l0%-lead-3% copper bearing was lowest at medium pressures. So that, it is useful for the medium duty of about 1000-1500 kgf/cm2.m/min. The maximum permissible PV value of iron-20% lead-3%o copper bearing was highest, about 3000 kgf/cm2⋅m/min. Therefore, it can be also used at the heavy duty.View full abstractDownload PDF (1825K)
- |<
- <
- 1
- >
- >|