Journal of the Japan Society of Powder and Powder Metallurgy
Online ISSN : 1880-9014
Print ISSN : 0532-8799
ISSN-L : 0532-8799
Search
Advanced search
OR
Browse
Search
Volume 61, Issue 6
June
Displaying 1-14 of 14 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
Paper
Paper
  • Effect of Oxygen Content in WC–FeAl Powders on Microstructure and Mechanical Properties of Sintered Composites Fabricated by Pulse Current Sintering Technique
    Ryoichi FURUSHIMA, Kiyotaka KATOU, Setsuo NAKAO, Zheng Ming SUN, Koji ...
    2014 Volume 61 Issue 6 Pages 281-289
    Published: June 15, 2014
    Released on J-STAGE: August 18, 2014
    DOIhttps://doi.org/10.2497/jjspm.61.281
    JOURNAL OPEN ACCESS
    Show abstractHide abstract
    The effect of oxygen content in WC–FeAl powder is examined on mechanical properties of the sintered composites. The oxygen content is varied by controlling the milling and/or drying processes of the WC–FeAl mixed powder. The WC–FeAl composites are obtained by sintering the mixed powders with the pulse current sintering technique. Transverse rupture strength is improved by reducing the oxygen content in the mixed powder whereas the difference of microstructure and composition is not observed clearly. Some results suggest that oxidation of FeAl during the preparation of the WC–FeAl mixed powder affects the mechanical properties of WC–FeAl products. It is concluded that oxygen content is very important for controlling the mechanical properties of WC–FeAl products.
    View full abstract
    Download PDF (1650K)
  • Microstructure and Strength of Fe–2%Cu–0.8%C Sintered Steel using Fe–Cu Alloy Powder
    Taku IWAOKA, Akira FUJIKI
    2014 Volume 61 Issue 6 Pages 290-297
    Published: June 15, 2014
    Released on J-STAGE: August 18, 2014
    DOIhttps://doi.org/10.2497/jjspm.61.290
    JOURNAL OPEN ACCESS
    Show abstractHide abstract
    Both copper wires and ferrous chassis are included in automotive scrap. Copper can directly influence the mechanical properties of steel products, and is generally considered to be a harmful tramp element. In contrast, copper is actively used for various sintered machine parts, because the Fe–Cu–C type can combine performance and economical efficiency, and does not require the advanced technique. Thus, a study was conducted utilizing powder metallurgy and Fe–Cu alloy powder to determine the possibility of using the rational processing of recycling copper-rich scrap. The microstructure and strength of the Fe–2%Cu–0.8%C compacts sintered with Fe–Cu alloy powder, were considerably influenced by the Fe/Fe–Cu powder mass ratio. The weight change decreased with the increase in the Fe/Fe–Cu powder mass ratio. This shows that graphite was consumed to reduce the reaction of oxide film on the Fe–Cu alloy powder surface. The strength of sintered compacts increased as the Fe/Fe–Cu powder mass ratio increased. For example, when Fe–Cu alloy powder is used in conjunction with an oxide film, the desirable Fe/Fe–Cu powder mass ratio is more than 3 in order to obtain a sintered compact with transverse rupture strength higher than 700 MPa.
    View full abstract
    Download PDF (1905K)
  • Electrochemical Properties of the Mesocarbon Microbeads (MCMBs) in an All-solid-state Electrochemical Cell by use of the Amorphous Solid Electrolyte Li3PS4
    Akizumi OGAWA,, Nobuya MACHIDA, Shunji KINOSHITA, Muneyuki NAITO, To ...
    2014 Volume 61 Issue 6 Pages 298-305
    Published: June 15, 2014
    Released on J-STAGE: August 18, 2014
    DOIhttps://doi.org/10.2497/jjspm.61.298
    JOURNAL OPEN ACCESS
    Show abstractHide abstract
    Electrochemical properties of the mesocarbon microbeads (MCMBs) were investigated as anode active materials for an all-solid-state cell in which amorphous Li3PS4 (a – Li3PS4) was used as solid electrolytes and Li – In alloy was used as a counter electrode. The amount of Li+ ions that were inserted into the MCMBs denoted as x in the notation LixC6 (0 < x < 1). X-ray diffraction measurements suggested that Li+ ions were inserted into the disordered portions of MCMBs at the initial reaction stage with the composition range of 0 < x < 0.13. After the initial reaction stage, Li+ ions were intercalated into the graphite layers of MCMBs in the composition range of 0.13 < x < 0.91. The Li+ ions inserted into the disordered portions of MCMBs could not be extracted in the discharge process and then caused the irreversible capacity of the first charge-discharge cycle. On the other hand, Li+ ions that were intercalated into the graphite layers can be reversibly deintercalated in the composition range of 0.13 < x < 0.91. The charge-discharge capacity of the MCMBs was gradually decreased with an increase in the cycle number. Raman spectroscopy suggested that the capacity fading during the charge-discharge cycles would be caused by the deterioration of the MCMBs’ crystallinity.
    View full abstract
    Download PDF (1341K)
  • Advanced Powder Processing Technology for Forming of Tiny and Thin Shape Products
    Zenzo ISHIJIMA, Hideshi MIURA
    2014 Volume 61 Issue 6 Pages 306-310
    Published: June 15, 2014
    Released on J-STAGE: August 18, 2014
    DOIhttps://doi.org/10.2497/jjspm.61.306
    JOURNAL OPEN ACCESS
    Show abstractHide abstract
    In order to improve the compactibility of tiny and thin thickness products, we have developed a new die compacting method which uses MIM’s raw material. A thin cup with a diameter of φ 2 was formed as an example. The W–Ni mixed powder and binder were kneaded and formed the pellets by backward extrusion, and clarified their deformation behavior. It was found that the deformation behavior consists of 3 stages; an initial stage of deformation until the pellet contact with the die as a result of upsetting, an intermediate stage of deformation from the contact with the die until the extrusion of the cup wall begins, during which the cavity is filled, and a final stage of deformation at which the wall undergoes further extrusion. The fluidity (viscosity) of the kneaded material becomes dominant at the molding of the cup wall part, and molding of a wall is increasingly influenced by pressure loss as decreasing wall thickness. Eventually, a compacting technology was established for cup shapes having a minimum thickness of 0.05 mm in the green compact which resulted in 0.04 mm by sintering.
    View full abstract
    Download PDF (930K)
Special Issue: High Functional Sintered Materials to Contribute to a Future Automobile
Summarization
Paper
  • Effect of Cu and Graphite Addition on the Properties of Sintered Compacts Made of Low Cr Prealloyed Powder
    Toshio MAETANI, Shigeru UNAMI, Tomoshige ONO, Yukiko OZAKI , Kuniaki O ...
    2014 Volume 61 Issue 6 Pages 313-317
    Published: June 15, 2014
    Released on J-STAGE: August 18, 2014
    DOIhttps://doi.org/10.2497/jjspm.61.313
    JOURNAL OPEN ACCESS
    Show abstractHide abstract
    The mechanical properties of the sintered compacts made of the Fe–0.5mass%Cr–0.2mass%Mn–0.2mass%Mo prealloyed powder (JIP® 5CRA) have been investigated. Tensile strength and hardness of the 5CRA material increased with the increases of addition of Cu and graphite, respectively. 5CRA–2.0mass%Cu–1.0mass%Gr material showed high-strength equivalent to that of the Fe–4.0mass%Ni–1.5mass%Cu–0.5mass%Mo–0.6mass%Gr material. Microstructure of the sintered compact of the 5CRA material containing Cu was consists of fine pearlite and some bainite. High-strength of the 5CRA material would be obtained by the effect of solid solution strengthening due to Cu addition and finer pearlite with graphite addition.
    View full abstract
    Download PDF (1422K)
  • Properties of Rolled and Carburized Sintered Gear Made of Ni–Mo Pre-alloyed Steel Powder
    Satoshi NISHIDA, Masaki YOSHIDA, Hironori SUZUKI, Teruie TAKEMASU, Tak ...
    2014 Volume 61 Issue 6 Pages 318-323
    Published: June 15, 2014
    Released on J-STAGE: August 18, 2014
    DOIhttps://doi.org/10.2497/jjspm.61.318
    JOURNAL OPEN ACCESS
    Show abstractHide abstract
    Finish gear rolling experiments, single tooth bending fatigue tests and gear running tests were carried out using P/M gears made of Ni–Mo pre-alloyed steel powder. A high precision CNC form rolling machine of two-roller dies transverse type was employed. The entire gear tooth flank was successfully densified from the tip to the root fillet by surface rolling. The durability test results show that the test case-carburized P/M gears with a density of 7.5 g/cm3 can achieve bending and surface fatigue strengths of 1.0 GPa and 2.0 GPa, respectively, which completely match with those of case-carburized SCM415 (0.15C–1.0Cr–0.2Mo–0.7Mn) wrought steel gears and those load bearing capacities tend to increase by surface rolling. The compressive residual stress near the gear flank surface is the level of 800 MPa, which is almost equivalent to that of wrought steel gear. The representative damages of P/M gears in gear running tests are pitting, which is the case with the wrought steel gear.
    View full abstract
    Download PDF (1508K)
  • Influence of Aluminum Addition on Sinterability and Thermoelectric Properties of Mg2Si Compound Prepared Using Liquid-solid Phase Reaction Method and Pulse Discharge Sintering
    Takashi ITOH, Akira TOMINAGA, Takahiro JINUSHI, Zenzo ISHIJIMA
    2014 Volume 61 Issue 6 Pages 324-328
    Published: June 15, 2014
    Released on J-STAGE: August 18, 2014
    DOIhttps://doi.org/10.2497/jjspm.61.324
    JOURNAL OPEN ACCESS
    Show abstractHide abstract
    Mg2Si compound is a promising material available for thermoelectric power generation using waste heat of temperature range of 600 to 900 K. However, high vapor pressure of molten Mg makes difficulties in synthesis of Mg2Si compound and in sintering. In order to overcome these problems, we synthesized the Mg2Si compound under Mg–rich condition by the liquid-solid phase reaction and sintered the synthesized powder by the pulse discharge sintering. In this study, we attempted to add aluminum of 0−2.0 at.% to the Mg2Si and investigated the influence of addition of aluminum on sinterability and thermoelectric properties. Addition of Al brought to improvement of the sinterability and reduction of the electrical resistivity. The 1.0 at.% Al–added sample had the maximum dimensionless figure of merit of 0.86 at 873K.
    View full abstract
    Download PDF (957K)
JSPM Announcements
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top