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Volume 29, Issue 5
Displaying 1-8 of 8 articles from this issue
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Keisuke ISHIMARU1979 Volume 29 Issue 5 Pages 171-172
Published: May 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (298K) -
Takeshi MEGURO, Naochika TORIKAI, Yoshitaka KOBAYASHI1979 Volume 29 Issue 5 Pages 173-178
Published: May 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSCombustion tests were carried out on aluminum pastes containing 50 to 90 wt% aluminum powder and aluminum powders stamped and atomized to examine the safety of aluminum pastes on fire. The tests included heating up to 800°C in an electric furnace, burning in a gas burner flame, and firing in a porcelain crucible by using a gas burner. Solvents in the pastes are only combustible and any indications of the dust explosion are unrecognized. Coagulation of the aluminum powders is found. Violent ignition takes place after combustion has been completed in the crucible in which the stamped powder is filled. The aluminum pastes resemble petroleum in combustion properties.View full abstractDownload PDF (1103K) -
Minoru FURUKAWA, Yasuhiro MIURA, Hiroya KAIEDA1979 Volume 29 Issue 5 Pages 179-185
Published: May 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSAluminum crystals of considerably low dislocation density were obtained through simple isothermal annealing followed by furnace cooling of single crystals grown from the melt. Characterization of lattice defects was made by means of X-ray diffraction topography at room temperature. Most of the dots are revealed to have no single Burgers vector of <110> or <111> type. They probably are dislocations and/or vacancy clusters bound to impurities. It seems that, in a macroscopic scale, some of the rows of prismatic dislocation loops are developed from helical dislocations and others are punched out from certain point sources. The difference in dislocation configuration between the two cases, annealed in air and in vacuum, is attributed to the difference in the nature of oxide layer.View full abstractDownload PDF (1968K) -
Hajime YAMADA, Takio TANAKA1979 Volume 29 Issue 5 Pages 186-190
Published: May 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe tool-chip contact length was artificially decreased by decreasing the width of first rake surface of double rake tool to examine its effect on the machinability of aluminum casting alloys. Decreasing the tool-chip contact length has a remarkable effect to improve the finished surface and to reduce the cutting force in machining such alloys as Al-5%Cu and Al-12%Si alloys having long natural tool-chip contact length. It is not so noticeable in maching such alloys as Al-Zn-Mg alloys having short natural tool-chip contact length. The tool wear is also reduced with shortening the tool-chip contact length.View full abstractDownload PDF (1061K) -
Shigeyoshi KITTAKA, Kinji SATO, Ryuichi MIYA, Kazuo OZAKI, Hozumi KAGA ...1979 Volume 29 Issue 5 Pages 191-196
Published: May 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSAluminum sheets O and 1/2H in hardness and 0.5 to 2.0mm in thickness were roll formed using urethan elastmer rolls 80°, 90°and 95°in hardness. The forming ratio is greatly affected by mechanical properties of the sheets. The O-sheets have better forming ratio than the 1/2-sheets. The 1/2H-sheets 1.5 and 2.0mm in thickness are incapable of forming into cylinders, while the O-sheets are capable regardless of their thickness. The maximum forming ratio is achieved for the O and 1/2H-sheets 2.0mm in thickness and for the rolls having different hardness. Both the O and 1/2H sheets 0.5mm in thickness are formed at a forming radius particularly greater than the sheets having more thickness. As the forming radius of the sheet approaches to a radius of steel roll, the formed radius is definitely limited corresponding to the materials, sheet thickness and forming conditions.View full abstractDownload PDF (683K) -
Hisashi SUZUKI, Motohiro KANNO, Yasuhisa SHIRAISHI1979 Volume 29 Issue 5 Pages 197-203
Published: May 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSAl-0.7 and 1.2%Mg2Si alloys (balanced alloys) and those containing excess Mg or Si (excess alloys) were investigated by means of hardness, electrical resistivity and specific heat measurements and high-resolution transmission electron microscopy. The alloys were completely solution-treated at 560°C, quenched, preaged at 20-100°C, and finally aged at 175°C. If preaged at low temperatures, the maximum hardness of the alloys two-step aged is generally inferior particularly in the excess alloys to that of the alloys aged usually at 175°C, because of the coarsening of needle-shaped G. P. zones. If the excess alloys are preaged at high temperatures, the maximum hardness is somewhat lower. It is suggested in the excess alloys that the amount of clusters formed during preaging increases, but most of them are impossible to transform into G. P. zones, because of their compositions and structures considerably apart from those of G. P. zones. The two-step aging is effective in the low Mg2Si balanced alloy in which precipitates are uniformly distributed.View full abstractDownload PDF (1496K) -
Nobolu MASUKO, Junichi SATO1979 Volume 29 Issue 5 Pages 204-215
Published: May 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (1437K) -
1979 Volume 29 Issue 5 Pages iii
Published: 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (131K)
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