All issues
Volume 28, Issue 1
Displaying 1-8 of 8 articles from this issue
- |<
- <
- 1
- >
- >|
-
Ichiro NAKAYAMA1978 Volume 28 Issue 1 Pages 1-2
Published: January 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDownload PDF (187K) -
Shiro HORIE, Tadahisa NAKAMURA, Masanori UEKI1978 Volume 28 Issue 1 Pages 3-7
Published: January 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSHot torsion tests and qualitative and quantitative microscopies were carried out. The stress-strain relation in the interrupted torsional deformation shows that the deformation resistance in the alloy soaked for 24hr decreases as much as about 20% compared with that soaked for 4hr. Improvement of the hot workability depends on the reduction of denuded zone around dendritic cast structure and on the refining and dispersion of the precipitated second phases with the proceeding of working process.View full abstractDownload PDF (2160K) -
Makoto TSUKUDA, Susumu KOIKE, Masayuki HARADA1978 Volume 28 Issue 1 Pages 8-14
Published: January 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESST6 conditions were examined on the Al-6.85%Si-0.30%Mg-0.20%Fe-0.12%Ti-1.006%Na alloy castings to select an optimum heat treating condition for automobile wheels. Solution heat treating at 540°C for 9hr and quenching into cold water (15°C) as soon as possible are recommended. The elongation and Charpy impact value are reduced by quenching in hot water or quenching after prolonged delay time. Aging at 180°C for 6hr ensures the highest strength, and aging at 140°C for 4hr does high elongation and impact strength.View full abstractDownload PDF (1334K) -
Hiroshi TSUDA, Taichiro ITO, Yutaka NAKAYAMA1978 Volume 28 Issue 1 Pages 15-19
Published: January 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe dependences of stress-strain curves, critical resolved shear stress (CRSS) and deformed structure on the aging temperature and time were studied on Al-0.4, -0.8 and -1.2at%Si single crystals. Stress-strain curves show parabolic hardening. The total elongation steeply decreases when CRSS begins to increase. CRSS reaches a maximum in the Al-0.8 and -1.2at%Si alloys aged at 150°C for 400hr, at 200°C for 4 to 6hr and at 250°C for 0.1hr, and decreases in those aged for longer time. Precipitates change in shape from sphere in the early stage of aging to rod or plate, and finally to lump. The band like deformed regions with high dislocation density in which dislocations severely curve are found in the low strained alloys at early stage of aging. Dislocations may cut through precipitates during deformation. The dislocation structure showing "by-pass mechanism" are found at the overaged stage.View full abstractDownload PDF (1107K) -
Tsuneo TAKAHASHI, Akihiko KAMIO, Hiroyasu TEZUKA1978 Volume 28 Issue 1 Pages 20-25
Published: January 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe solid-liquid interface structures unidirectionally growing in <100>, <110> and <111> directions were examined in 99.997%Al, Al-Zn and Al-Ti alloys. The interface successively transforms from planar to hexagonal cellular in accordance to the constitutional undercooling regardless of crystallographic orientation. Little preferability is found, in the cellular growth direction. The interface of grain having a growth orientation near <111> morphologically transforms at an earlier stage, because the {111} plane grows slowest and easily entraps the solute built-up at the interface. Elongated cells are formed on the growing interfaces of <100>, <110>, and <111> orientations. They arrey most regularly in <110> orientation and less regularly in <100>. The elongated cells formed on the {110} growing interface become regular hexagonal cells with changing freezing conditions.View full abstractDownload PDF (1403K) -
Itsuo OHNAKA, Tatsuichi FUKUSAKO, K.E. Höner1978 Volume 28 Issue 1 Pages 26-34
Published: January 30, 1978
Released on J-STAGE: November 05, 2008
JOURNAL FREE ACCESSAl, Al-1% and -4.5%Cu and Al-11.6%Si alloys were bottom poured in a cylindrical steel mold (70mm dia. and 200mm height). The cast surfaces have such patterns as spiral grooved patterns on pure Al and Al-Si ingots, spiral white bands, dappled patterns on Al-Cu ingots, small semispherical protuberances in dia.200 to 400μm especially on Al-1%Cu ingots, and indistinct white stripes on pure Al. Cu segregates on the surfaces of Al-Cu ingots. These surface appearances are susceptible to the rate of melt-surface rise, pouring temperature and grain refining. The experimental facts are explained on the bases of solidified structures, remelting, coarsening and resistance of meniscus to deformation.View full abstractDownload PDF (2331K) -
Tsuneo TAKAHASHI, Takeshi MURAKAMI, Cong Danh NGUYEN1978 Volume 28 Issue 1 Pages 35-40
Published: January 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe cube texture is considerably developed in the 3004 alloy sheets hot rolled, partially annealed up to about 50%, rolled about 10% in reduction, and annealed. The orientation in the annealed sheets having sharp cube texture changes by lattice rotation during final cold rolling. The sheets rolled by 85% in reduction have a rolling texture composed both of the Cu-type rolling texture and (0kl) [100] orientation. The (0kl) [100] orientation is developed by lattice rotation of cube orientationa round the <100> axis parallel to the rolling direction. The sharper are the cube texture before final cold rolling, the more reduced is the 45° earing in cups of super hard sheets, because the components of (0kl) [100] orientation contribute to forming 0°-90° earing and reducing 45° earing.View full abstractDownload PDF (736K) -
Muneo SUZUKI1978 Volume 28 Issue 1 Pages 41-53
Published: January 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDownload PDF (2822K)
- |<
- <
- 1
- >
- >|