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Volume 26, Issue 10
Displaying 1-7 of 7 articles from this issue
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Tamiro HIRAKAWA1976 Volume 26 Issue 10 Pages 493-494
Published: October 30, 1976
Released on J-STAGE: July 23, 2008
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Sumio NAGATA, Hidetoshi UENO, Koji IMAGAWA, Akira KITAHA, Shigeru AKIY ...1976 Volume 26 Issue 10 Pages 495-500
Published: October 30, 1976
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSTwo processes "pre-pack method" and "pre-mix method" are applicable to produce fine hollow grains of volcano glass-aluminum composites (SBAC in short). The former includes packing the glassy grains in a die cavity and squeeze-casting molten aluminum. The latter includes mechanically pre-mixing the grains and molten aluminum and press-forming the slurry mixture in a die cavity. Properties of this composite having low density produced in the latter process were determined comparing with those produced in the former process. Test items were metallurgical structure, specific gravity, volumertic fraction of the grains, tensile, compressive, and impact strengths, thermal and electrical resistances, and thermal expansion.View full abstractDownload PDF (695K) -
Yoshimitsu MIYAGI, Masakazu HIRANO1976 Volume 26 Issue 10 Pages 501-509
Published: October 30, 1976
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSEffects of homogenization conditions of ingots on stress corrosion resistance (SCR) of Al-Zn-Mg alloy ingots, plates and extrusions were investigated.
(1) SCR of ingots decreased with increased homogenizing temperature.
(2) SCR of plates in ST-direction was independent of homogenizing conditions, but in LT-direction decreased by homogenizing at too high temperature.
(3) In LT-direction, SCR of plates was superior to that of ingots, but in ST-direction inferior to that of ingots.
(4) SCR in LT-direction of extrusions without homogenization decreased when extrusion speed was higher, while that of extrusions extruded at lower extrusion speed was independent of homogenizing conditions.
(5) In the structural factors depending on homogenization and hot working conditions, grain shape was a potential factor governing SCR.
(6) Relationship between SCR and grain shape was explained by the assumption that the higher the per-pendicular component to grain boundary of applied stress, and the flatter and the more monotonous the grain boundary, the longer the stress corrosion cracking life.View full abstractDownload PDF (2842K) -
Ken TOHMA, Yo TAKEUCHI1976 Volume 26 Issue 10 Pages 510-518
Published: October 30, 1976
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSAluminum and such dispersion type aluminum alloys as Al-Fe, Al-Co and Al-Ni and, for comparison, Al-Mg alloy were cold rolled, and work hardening characteristics as well as mechanical properties at high strains were investigated. When annealed materials are incrementaly deformed, hardness increases at first. Al-Fe, Al-Co and Al-Ni alloys as well as aluminum exhibit work softening phenomenon at high strains. This softening phenomenon is characteristic ecpecially with Al-Co alloys. These alloys have lower strength and higher ductility than those of aluminum at extremely high strain. Transmission electron microscopy shows that dislocations are arranged in cellular structure and that no distinct deformation dependence of cell size is observed. It is concluded that work softening phenomenon can be understood in terms of high recovery rate during or immediately after rolling deformation.View full abstractDownload PDF (2058K) -
Hisashi SUZUKI, Motohiro KANNO, Kazuhiro ITOI, Mikio FUZII1976 Volume 26 Issue 10 Pages 519-525
Published: October 30, 1976
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe aging phenomena of Al-3.8%Cu-Be alloys having up to 0.093%Be and Al-3.8%Cu-0.09%Be-0.05%Cd alloy were investigated mainly as a function of aging temperature and Be content by means of electrical resistivity and hardness measurements, and transmission electron microscopy. Specimens were solution-treated at 520°C for 2hr, quenched and subsequently aged at temperatures ranging from 0 to 200°C.
(1) The aging retardation or acceleration at low or high temperature was found to occur in the ternary alloys with increasing Be contents, but the extent was very small compared with Sn (Cd) containing alloys.
(2) The aging acceleration resulted from the fact that θ' phases easily formed in the matrix of ternary alloys in the same way as in Sn (Cd) containing alloys. Be rich phases which would act as heterogeneous precipitation sites for θ' phases were never observed in contrast to Sn (Cd) containing alloys in which Sn (Cd) rich phases have so far been observed.
(3) The above aging phenomena in the ternary alloys were enhanced by the addition of Cd, showing that the effect of additional elements didn't offset each other.
(4) The mechanism for the aging phenomena of Al-Cu-Be alloy was considered to be quite different from that of Al-Cu-Sn (Cd) alloys.View full abstractDownload PDF (1299K) -
Motohiro KANNO, Hisashi SUZUKI, Taku KITAYAMA1976 Volume 26 Issue 10 Pages 526-530
Published: October 30, 1976
Released on J-STAGE: November 05, 2008
JOURNAL FREE ACCESSHigh resolution transmission electron microscopy was made on the alloys which were preaged under the conditions, 100°C ×1000min and 130°C×4000min, in order to develop G. P. (1) and G. P. (1) plus G. P. (2) structures (so far as the binary alloy was concerned) respectively, and reversion heat-treated at 200°C and 250°C for various times.
G. P. zones in the binary alloy reversion heat-treated at 200°C were apt to disappear, but some of large ones remained after all and turned to grow up to form G. P. (2); coarse G. P. zones in the ternary alloy (corresponding to G. P. (2) in the binary alloy, ie. G. P. (X2)) simply remained and changed into θ' phase in a short time, where 200°C was higher than any solvus temperature of G. P. (1) or G. P. (X2). Complete reversion of G. P. zones was found in the binary alloy treated at 250°C, but some of G. P. (X2) changed into θ' in the ternary alloy. The accelerated θ'-formation in the ternary alloy would relate to the Sn-rich phase appearing at the corner of the G. P. (X2) zone in the early stage of reversion. Heterogeneous precipitation of θ' always appeared during the above reversion heattreatment.
Complete reversion of G. P. zones was not always expected even in the reversion at higher temperature than G. P. zone solvus one. Complete reversion would be closely related to the pre-aging condition as well as reversion temperature. Ideal solid solution could hardly be brought out in general by means of usual reversion heattreatment.View full abstractDownload PDF (1008K) -
Noboru MASUKO, Masao TAKAHASHI1976 Volume 26 Issue 10 Pages 531-536
Published: October 30, 1976
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSDownload PDF (871K)
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