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Volume 33, Issue 2
Displaying 1-9 of 9 articles from this issue
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[in Japanese]1986 Volume 33 Issue 2 Pages 57-62
Published: February 25, 1986
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSDownload PDF (430K) -
Kohmei Halada, Hiroo Suga1986 Volume 33 Issue 2 Pages 63-68
Published: February 25, 1986
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSSome of the processing parameters for centrifugal atomization of molten metal were studied by means of a model-experiment using water.
The shape and revolution velocity of the high speed rotating stages affected the size and the scattering distribution of disintigrated droplets. In the atomization using a flat stage, liquid disintegrated into smaller particles but sticked considerably to the wall of the apparatus. Conical type stages lessened the sticking and increased the portion of the larger drops slightly. Higher velocity revolution made finer particles and narrowed the scattering range of drops at the bottom of the chamber closely to the center. The wettability of the liquid on the stage surface was found to be an important factor for the disintegration of the liquid. Enhanced wettability brought direct drop formation, while poor wettability brought ligament disintegration.View full abstractDownload PDF (5586K) -
Ryuzo Watanabe, Hideo Suzuki, Heihachi Shimada1986 Volume 33 Issue 2 Pages 69-72
Published: February 25, 1986
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSElastic deformation behavior in the porous copper compacts under static compression was studied by Speckle Photography. The advantages of using the Speckle Photography have been emphasized for the determination of small strain distribution in porous compacts.
The results of this study are summerized as follows:
(1) The small strain of the order of 10-4 with a gauge length of less than 1 mm was able to be detected by the present method.
(2) Young's Modulus distributions evaluated from the strain measurement along specimen axes of the porous compacts were confirmed to correspond well to the existing porosity distribution.View full abstractDownload PDF (1497K) -
Shigeaki Uehara, Hisaoki Sasano, Takayuki Yoshioka, Kazuhiro Honma, To ...1986 Volume 33 Issue 2 Pages 73-77
Published: February 25, 1986
Released on J-STAGE: December 04, 2009
JOURNAL FREE ACCESSRelation between oxygen content and martensitic transformation temperature of the TiNi compacts prepared by a blended elemental approach has been studied. In this experiment, it was found that the Ms temperature decreases linearly with increasing oxygen content in the composition range less than 5200 p.p.m. of oxygen and that the precipitates which have fee structure with 11 Å of lattice constant exist appearently in the alloys containing more than 2700 ppm of oxygen. All experimental results obtained seem to suggest that the composition of the precipitates is Ti4Ni2O. Consequently, the decrease in Ms temperature could be attributed to the enrichment of nickel in matrix induced by the precipitation.
In order to pull up the Ms temperature toward the same level of that obtained in ingot materials, the effect of aging on the Ms temperature and that of excess addition of titanium powders in preparing the TiNi compacts have also been investigated. Both attempts were confirmed successfully to be useful for raising the Ms temperature.View full abstractDownload PDF (3073K) -
Shigeya Sakaguchi, Hiroshi Ito, Ryozo Nakamura1986 Volume 33 Issue 2 Pages 78-83
Published: February 25, 1986
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSA high chromium cast iron (Fe-15Cr-3.66C) was applied as an infiltrant to WC-Ni skeletons because of its high hardness and high wear resistance, and some properties of iron-chromium-carbon alloy infiltrated WC-Ni skeletons were investigated.
The results of this work can be summarized as follows:
(1) The uniform and hard alloys were obtained easily by means of the double direction infiltration process.
(2) Wear resistance of this alloy was better than that of the nickel-phosphorus alloy infiltrated WC-Co skeleton, and almost the same as that of the sintered WC-18Co alloy.
(3) Corrosion resistance of this alloy against some acids was almost the same as that of the sintered WC-9Co alloy.
These improved properties will be caused by both a chromium-iron double carbide (K2 type) and chromium dissolved in the binder of this alloy.View full abstractDownload PDF (1767K) -
Koji Hayashi, Yoshihiro Onomura1986 Volume 33 Issue 2 Pages 84-87
Published: February 25, 1986
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThe effects of additions of C(≤9mol%) and/or SiO2 (≤3mol%) on microstructure and room-temperature strength were investigated for Si3N4-10 mol%MgO-5.5mol%Al2O3 ceramics which was sintered in N2 of 0.1 MPa at 1973 K for 3.6 ks by using Si3N4 powder with impurities of 1mol%C and 4 mol%SiO2.
The strength of ceramics monotonously decreased with increasing C and increased with increasing SiO2 up to a certain value. The deteriorative effect of C on strength became fairly moderated by the addition of SiO2. These results were discussed in terms of microstructure, size of fracture source, toughness of matrix, etc.View full abstractDownload PDF (1777K) -
Koji Hayashi, Yoshihiro Onomura1986 Volume 33 Issue 2 Pages 88-91
Published: February 25, 1986
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSIt has already been clarified in the authors' previous study on Si3N4-10 mol%MgO-5.5 mol%Al2O3 ceramics that the annealing at about 1370 K caused a sharp decrease in the strength of ceramics with the formation of MgSiO3. In this study, the effects of contents of MgO (7-20 mol%) and Al2O3 (3.5-9.5 mol%) and additional amount of SiO2 (1-3 moloo) on the formation of MgSiO3 and the change in the strength due to the annealing were investigated.
It was found that the increasing of MgO content and decreasings of Al2O3 and SiO2 contents depressed the formation of MgSiO3. In particular, the increasing of MgO content was most effective and the formation of MgSiO3 was completely inhibited at about 20 mol%MgO. In accordance with this, the strength of ceramics with 20 mol%MgO was hardly varied by the annealing. Some discussions were made on these results, using MgO-Al2O3-SiO2 psuedo-ternary phase diagram.View full abstractDownload PDF (287K) -
Hisashi Suzuki, Hideaki Matsubara, Akira Matsuo, Kunio Shibuki1986 Volume 33 Issue 2 Pages 92-97
Published: February 25, 1986
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSThe Ti(C, N) layer (C/N ≈ 4/6) was deposited by PVD process at 573-853K on the TiC0.7N0.3-Mo2C-Ni substrates having transverse-rupture strength as high as 2.5-2.8 GPa. The interface structure between layer and substrate, transverse-rupture strength, residual stresses in the layer, cutting performance, etc. were studied for the PVD coated specimens.
The η phase did not appear near the interface even after annealing the coated specimens. The strength of coated specimens was the same as that of substrate when the PVD temperatures became lower. The strength of specimens sharply decreased by annealing with increasing the annealing temperature. These results on the strength were almost similar to those in case of coated WC-Co alloys previously reported. The strength of coated alloys, i.e. coated cermets and cemented carbides, was well explained, considering the facts that residual compressive stresses were produced in the layer and they varied according to the PVD and annealing temperatures. It was proved that cutting performance of coated specimens was superior to that of uncoated specimens.View full abstractDownload PDF (3702K) -
Hideo Torii, Satoru Yuhaku, Hideyuki Okinaka1986 Volume 33 Issue 2 Pages 98-102
Published: February 25, 1986
Released on J-STAGE: May 22, 2009
JOURNAL FREE ACCESSWell-sintered zirconia ceramics are hardly obtained by conventional solid state reaction below 1500°C.
However, it was found that the sinterability of the zirconia ceramics can be enhanced by using the mixed powders composed of ZrO2 raw powder and a pulverized calcined ZrO2 powder containing high concentrations of Y2O3. For example, the well-sintered partially stabilized zirconia ceramics containing 5 mol% Y2O3 was able to be prepared by firing even at 1300°C using the ZrO2 powder containing 40 mol% Y2O3 and ZrO2 raw powders.View full abstractDownload PDF (3473K)
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