Journal of Japan Institute of Light Metals
Online ISSN : 1880-8018
Print ISSN : 0451-5994
ISSN-L : 0451-5994
Volume 54, Issue 7
Displaying 1-6 of 6 articles from this issue
RESEARCH REPORT
  • Katsura KAJIHARA, Yasuaki SUGIZAKI, Yuuichi SEKI
    2004 Volume 54 Issue 7 Pages 273-279
    Published: 2004
    Released on J-STAGE: February 20, 2007
    JOURNAL FREE ACCESS
    Microstructure and precipitation control for optimizing processing conditions is vitally important for improvement of quality of wrought aluminum alloys. In this study, a model was presented for the precipitation behavior of impurity Fe and Si in commercial purity aluminum. The model was basically constructed under the nucleation and growth theory. The equilibrium stability and solvus temperature of precipitates and equilibrium solvus boundaries of Fe and Si in solid solution were determined by thermodynamic calculation for Al–Fe–Si alloys. The temperature–time-precipitation (TTP) curves for Al3Fe and α-AlFeSi were mainly described in this paper. In addition, as the effects of strain-induced precipitation, a stored energy term was added to the rate of heterogeneous nucleation, in which the effects of recovery and recrystallization were taken into account.
    As an experimental verification of this model, the changes in solute Fe contents during isothermal annealing in the un-deformed and hot-deformed specimens were quantitatively investigated by chemical analysis of extracted residue with phenol (phenol residue method). The present model quantitatively explained the experimental results, in particular, concerning TTP curves and the accelerated precipitation due to strain.
    Download PDF (764K)
  • Tomoshi TAKAHASHI, Nobuyuki MATSUDA, Shuji KUBO, Takanori HINO, Masao ...
    2004 Volume 54 Issue 7 Pages 280-286
    Published: 2004
    Released on J-STAGE: February 20, 2007
    JOURNAL FREE ACCESS
    The interdiffusion experiments of Ti-rich β Ti–Al–Cr alloys have been performed in the temperature range from 1273 to 1473 K. The concentration profiles indicate that the diffusion distance of Cr is somewhat longer than that of Al in the solid solutions. The diffusion paths show S-shaped curves. The formation of S-shaped diffusion paths is attributed to the difference between the diffusion distance of Cr and Al. The direct and indirect interdiffusion coefficients are positive in the ternary alloys, and the four interdiffusion coefficients are not sensitive to the solute concentrations. The ratio of indirect coefficient to direct one suggests that repulsive interactions exist between Al and Cr atoms in the Ti–Al–Cr alloys. In addition, the ratio values of converted interdiffusion coefficients in the ternary alloys suggest that the interactions between Ti (solvent) and Cr atoms are attractive in the present alloy.
    Download PDF (933K)
  • Yingjun JIN, Takashi KUBOKI, Makoto MURATA
    2004 Volume 54 Issue 7 Pages 287-292
    Published: 2004
    Released on J-STAGE: February 20, 2007
    JOURNAL FREE ACCESS
    Incremental in-plane bending which has been invented by authors is a new and flexible manufacturing technology for small-lot production of sheet metal with various bending radii. The sheet metal is bent incrementally by an inclined-punch beating. The prototype incremental bending machine uses the numerical control technology and bends the sheet metal flexibly. The bending experiments are carried out and some experimental results such as beating force, bending radius, strain distribution are experimentally examined. The forming properties of in-plane bending are clarified in this study. Moreover, approximate formulas for calculating the bending radius are proposed base on the plane strain. The bending radius calculated by the proposed formula agrees with the one of the experiments.
    Download PDF (799K)
  • Takehiko WATANABE, Yoshitaka SUGIYAMA
    2004 Volume 54 Issue 7 Pages 293-297
    Published: 2004
    Released on J-STAGE: February 20, 2007
    JOURNAL FREE ACCESS
    In this study, resistance spot welding was applied to make a dissimilar-metal joint between Mg alloy AZ31B plate and commercially pure Al plate. Factors affecting the cross tensile strength of the joint and the effect of Ag insert on the joint strength were investigated. The main results obtained in this study are as follows.
    The strength of the dissimilar-metal joint of Mg/Al increased with increasing welding current, however, the strength was very low and was about one forth to one fifth that of the similar-metal joint of Mg/Mg made under the same condition.
    By using insert metal consisting of four layers of Ag foil with 0.1 mm thickness, the strength of the Mg/Ag joint increased about 1.5 times than that of the Mg/Ag joint without the insert metal.
    With increase in the thickness of the foil-layered Ag insert metal, the thickness of an intermetallic compound formed at the interface between Mg and Ag decreased and the thickness of a eutectic reaction layer between Ag and Al increased, resulting in the increase in the Mg/Al joint strength. However, when the insert metal of 5-layers Ag foil was used, the strength of the Mg/Ag joint decreased because non-bonded regions occurred in the eutectic reaction layer.
    Download PDF (1767K)
REVIEW
LECTURE
feedback
Top