Journal of Japan Institute of Light Metals
Online ISSN : 1880-8018
Print ISSN : 0451-5994
ISSN-L : 0451-5994
Volume 46, Issue 7
Displaying 1-7 of 7 articles from this issue
RESEARCH REPORT
  • Hiromitsu KANEDA, Takao CHOH
    1996 Volume 46 Issue 7 Pages 321-326
    Published: 1996
    Released on J-STAGE: March 30, 2007
    JOURNAL FREE ACCESS
    Experiments were carried out on the spontaneous infiltration of magnesium melt to powder bed, to find out an appropriate infiltration agent powder of which was mixed with reinforcements previously. In this work, TiO2 (anatase and rut-ile), MnO, ZnO and CuO powders were tested as an infiltration agent, using SiCp powder (average diameter was from 2 to 8 μm) as a reinforcement. In addition, to investigate the effect of particle diameter of infiltration agent on the spontaneous infiltration, the milled smaller SiO2 of average diameter 1 μm was also tested. The infiltration was performed at 973 K under pure argon gas atmosphere for 1.2 ks holding time. Furthermore, infiltration velocity was also measured. It was found that only TiO2 (anatase) could be used as an infiltration agent, and that the infiltration behavior to the powder bed mixed with anatase was different from that mixed with SiO2 and affected also by matrix metal, pure magnesium or AZ91 alloy. The infiltration velocity in the case of anatase as a agent was lower than that in the case of SiO2. The critical content of smaller SiO2 agent for the occurrence of infiltration decreased, and the infiltration velocity increased by mixing the larger SiO2.
    Download PDF (910K)
  • Masahiro INOUE, Yuichiro ITOH, Katsuaki SUGANUMA
    1996 Volume 46 Issue 7 Pages 327-333
    Published: 1996
    Released on J-STAGE: March 30, 2007
    JOURNAL FREE ACCESS
    The suitable fabrication condition for the two types of reaction synthesis processes of FeAl were investigated. In the reactive sintering of pre-mixed elemental powders, homogination and densification above 99% of the relative density were achieved by vacuum hot pressing at 1273–1500 K with 20 MPa of applied pressure. The isothermal holding at the temperatures above 1273 K is necessary to remove pores generated during exothermic reaction at 933 K in this hot pressing condition. The another process studied in this work is the squeeze casting of aluminum melt into porous iron sintered bodies (SQ method). The homogeneous aluminides were not formed by in-situ reaction in the SQ method, however, dense and uniform FeAl was obtain by the combination of SQ method and post hot pressing (pseudo-isostatic pressure) treatment.
    Download PDF (1503K)
  • Byoung-Kwon SUH, Yong-Tak CHO, Chi-Hwan LEE
    1996 Volume 46 Issue 7 Pages 334-339
    Published: 1996
    Released on J-STAGE: March 30, 2007
    JOURNAL FREE ACCESS
    The effects of degassing treatment on mechanical properties of the SiCp/2024Al alloy composites fabricated by powder extrusion were investigated. The degassing temperatures determined from gas chromatography analysis of extracted gases were room temperature and 450°C. The undegassed powders and the powders degassed at room temperature and 450°C were extruded at 500°C. The principal gases extracted by degassing were H2O and H2. The thickness and kind of the oxides formed on aluminum powder surface were characterized by Auger electron spectroscopy and scanning electron microscopy. The oxidation of aluminum powder surface was accelerated by H2O above degassing temperature of 350°C. It was found that the oxides consist of MgO and Al2O3. The mechanical properties of the composites degassed at 450°C were higher than those of the undegassed composites and the composites degassed at room temperature. These results show that the degassing treatment at high degassing temperature (~450°C) is necessary to improve the mechanical properties of the SiCp/2024Al alloy composites by powder extrusion.
    Download PDF (1318K)
RESEARCH NOTE
TECHNICAL REPORT
LECTURE
feedback
Top