巻号一覧
46 巻, 5 号
選択された号の論文の6件中1～6を表示しています
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研究論文
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北澤 君義, 林 真太郎, 山崎 純生1996 年 46 巻 5 号 p. 219-224
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーIn order to reduce a tool-path schedule for hemispherical stretch-expanding of sheet metal, a CNC incremental forming process with two path method in which a hemispherical shell is stretch-expanded from a flat blank by means of conical stretch-expanding and the following hemispherical stretch-expanding in two continuous tool-path stages has been devised. Hard and soft aluminum sheets were stretch-expanded to hemispherical shells with diameter of 68 mm by using CNG incremental forming machine, and the deformation behavior was experimentally investigated. Experimental results showed that the success of the process depended much on the preventing condition of rupture and large deflection during the stages. It was, therefore, concluded that the proposed two path method was very useful for reduction of the tool-path schedule for CNC incremental hemispherical stretch-expanding of sheet metal.抄録全体を表示PDF形式でダウンロード (1046K) -
北澤 君義1996 年 46 巻 5 号 p. 225-230
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーIn order to prevent the phenomena of outward curling and waving in flaring of tubes, deformation behavior in rotary flaring process with off-centered tool was experimentally investigated. The influence of the off-centered distance between tool axis and tubular axis δ, the feed of tool per revolution f, tool angle, tube diameter and lubricant were studied by using aluminum and aluminum alloy tubes. It was found that, by increasing δ and decreasing f, the formation of outward curling and waving could be avoided in the flaring process. Furthermore, it was also clarified that these parameters, δ and f, were closely connected with the contact area ratio X which denotes the ratio between the contact area and the total deformed area of the tube. X was proved to be the controlling factor for the formation of outward curling and waving. Experimental results showed that X recommended for practical use should be lower than a minimum X to prevent waving.抄録全体を表示PDF形式でダウンロード (753K) -
関 史江, 中居 道弘, 伊藤 邦夫1996 年 46 巻 5 号 p. 231-236
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーA laser shot local melting technique was applied as an artificial nucleation process. Pure aluminum processed through ingot metallurgy and an Al–2%Fe powder metallurgy alloy were cold swaged. The surface layer of specimen cut from the swaged bar parallel or perpendicular to the swaging direction (SD) was melted by one by one shots of laser and then the specimens were annealed. In pure Al shot parallel to SD, [100] oriented grains pre-existing in the unmelted matrix grow continuously by re-solidification and grow back into the matrix by recrystallization, developing a strong [100] recrystallization texture. While this is not the case for pure Al shot perpendicular to SD. In Al–2Fe shot parallel to SD, a [100] solidification texture seems to develop not by growth of matrix grains but by independent nucleation. The re-solidified grains do not grow by recrystallization, leading to the formation of the previously reported [110] texture in the matrix. It is argued that the anisotropic growth behavior of [100] re-solidified grains by recrystallization in pure aluminum may stem from structural characteristics of its deformed matrix, while in the PM alloy compound particles suppress both growth of pre-existing grains by re-solidification and growth of re-solidified grains by recrystallization.抄録全体を表示PDF形式でダウンロード (992K) -
金 大洲, 中山 栄浩, 鷹合 徹也, 小野田 義富1996 年 46 巻 5 号 p. 237-242
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーThe mechanical properties of the commercial 5083 aluminum alloy specimen cut in the direction parallel to the short-transverse direction of the plate were measured by tensile and Charpy impact tests at 77 K and 300 K in order to study the generation behavior of laminated cracks. Changes in the mechanical properties with the long-term aging were also investigated in view of precipitation of β–phase. The specimens were solution treated at 673 K for 7.2×103 s, water quenched and aged subsequently at 453 K for up to 107 s. The absorbed energies during the impact fracture tests showed a lower value than those of the specimens cut in the other directions, suggesting the reason for laminated cracking in the longitudinal direction. The absorbed energy, tensile strength and fracture elongation decreased steeply for the specimens aged for longer than 106 s, corresponding to the marked precipitation of β–phase. According to the results of fractographic observation, flat surfaces in brittle manner were obtained for aged specimens having low mechanical properties.抄録全体を表示PDF形式でダウンロード (1034K) -
長谷川 収, 西村 尚1996 年 46 巻 5 号 p. 243-248
発行日: 1996年
公開日: 2007/03/30
ジャーナル フリーWorkability of four types of aluminum alloy cross sections (A6061–T6, A6061–O, A6063–T5 and A6063–O) have been investigated by performing efficient press bending with different cross sections, specimen thicknesses and bend radii. A mechanical press was used in these experiments without a mandrel. Inferior forming has been classified into the following subcategories: collapse, crack, wrinkle and succumb. Collapse and crack don't occur on annealed materials with sufficient ductility. Wrinkles are observed at the compression part of the web and at the compression flange in many specimens. Succumb is observed only in the channel that has compressive and tensile flanges and a web, both flanges move towards the neutral surface due to the same mechanism causing wrinkling and sagging of flanges of closed cross section profiles. Cross sectional deformation has been evaluated by cross-sectional distortion ratios α and β, and wrinkle height h. Profiles with a rib which connects both flanges have the advantage of getting the small α, β and h. The workability and cross sectional distortion of aluminum shapes are found to be influenced by the material ductility, flow stress, thickness, bend radii and cross sectional shape.抄録全体を表示PDF形式でダウンロード (667K)
連載講座
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藤川 辰一郎1996 年 46 巻 5 号 p. 254-265
発行日: 1996年
公開日: 2022/02/15
ジャーナル フリーPDF形式でダウンロード (10414K)
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