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Volume 28, Issue 6
Displaying 1-7 of 7 articles from this issue
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Yoshishige TSUMURA, Akisaku SAKAKIBARA, Katsusaburo TOYODA1978 Volume 28 Issue 6 Pages 261-266
Published: June 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSAn operation has been developed for demagging, which includes melting an aluminum alloy, superposing a layer of molten chlorides bath upon the molten alloy, and passing a direct current between the molten alloy as an anode and iron cathode imersed in the molten bath. Chlorine electrodeposited upon the anode surface of the molten alloy preferentially reacts with magnesium into magesium chloride and demags the aluminum alloy. If the chlorides bath contains considerable amount of magnesium chloride, magnesium is electrodeposited on the iron chathode and reclaimed as a metal. The"current density limit", i.e. the highest current density where electrodeposited chlorine preferentially reacts with magnesium but not with aluminum is found as a bend on current-potential curve. The efficiency for demagging 100% is achieved within the limit. The standard operation in which magnesium is removed from 0.75 to 0.25% requires electric power consumption 4.04KWh per magnesium removal 1kg and magnesium 0.8kg is reclaimed as a metal in contrast with the conventional process in which chlorine 2.92kg is required. Neither harmful chlorine nor aluminum chloride emits in the operation.View full abstractDownload PDF (887K) -
Takeshi MURAKAMI, Cong Danh NGUYEN, Tsuneo TAKAHASHI1978 Volume 28 Issue 6 Pages 267-271
Published: June 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSPreferential growth of cube-oriented grains through grain boundary migration was investigated by microfocused X-ray diffraction. In aluminum 99.99% purity, cube textures with small orientational spread develop when rolled to 90% reduction, partially annealed up to the recrystallization percentages 5 to 40, and additionally rolled to 30% reduction. Cube grains surrounded by deformed matrix are deformed by additional rolling. Cube grains which cause sharp Laue spots at the same position to the asterisms due to the strained cube grains grow into deformed matrix before non-cube grains recrystallize from the deformed matrix upon annealing. Strained cube grains recover without reorientation, and consequently coalesce with strain-free cube grains. Migration of boundary of cube grains and recovery of the strained cube grains take place as easily as the orientations of cube grains are closer to the ideal orientation (001) [100].View full abstractDownload PDF (1347K) -
Mototaro SATO1978 Volume 28 Issue 6 Pages 272-276
Published: June 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSFine or micro-cutting of aluminum alloys in which the depth of cut is decreased permits a characteristic cutting mechanism different from conventional cutting. The size effect appeared in a specific cutting force when a depth of cut reaches a some value. The depth of cut, i.e. the critical depth of cut is closely related with the nose radius of cutting edge. The cutting in which the depth of cut is less than 5μm has a similar cutting mechanism as abrasive grain cutting on the basis of the forces ratio of cutting resistance Fv/FH. The shear angle rapidly decreases as the depth of cut decreases probably because of reduce in the effective angle. The nose radius of cutting edge has an important effect on the sliding length of cutting edge until chip begins to form.View full abstractDownload PDF (1147K) -
Shiro KOHARA, Mototsugu KATSUTA1978 Volume 28 Issue 6 Pages 277-283
Published: June 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSThe uniaxial deformation behavior of aluminum alloy sheets containing 1 to 6%Mg was determined through a tensile test, and the biaxial deformation behavior, through hydraulic bulging, rigid punch forming with scribed circle and Erichsen cupping tests. The anisotropy of the sheets changes with magnesium content. The planar anisotropy parameter Δr is positive for 1 to 3%Mg, almost zero for 4%Mg and negative for 5 to 6%Mg. The average values in the uniaxial test are correlated fairly well with those in the biaxial test for fracture strength, strength coefficient K and work hardening exponent n. For the strain to failure, however, no correlation is found between the average uniaxial values and the biaxial ones.View full abstractDownload PDF (1440K) -
Hisashi SUZUKI, Motohiro KANNO, Hideo TANABE, Kazuhiro ITOI1978 Volume 28 Issue 6 Pages 284-291
Published: June 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSOptical and transmission electron microscopies and X-ray diffraction were carried out on transformation of a metastable Al6Fe or AlmFe in the eutectic structure in relation to the "fir tree structure". Specimens containing either Al6Fe or AlmFe in the eutectic were isothermally annealed at 500° to 600°C. As for Al6Fe→Al3Fe transformation, stable Al3Fe nucleates at the edge of rod-shaped Al6Fe contacting to the matrix-eutectic interface in the early stage of annealing. It grows with dissolution of Al6Fe facing to the stable Al3Fe. The AlmFe transforms into Al3Fe in the same mode. The estimated activation energy 1.4 to 1.6eV for Al6Fe→Al3Fe transformation suggests that the transformation is controlled by the diffusion of dissolved Fe atoms in the α-phase in the eutectic. None of intermediate phase is found during the transformation. The time required for eliminating AlmFe is shorter than that for eliminating Al6Fe, probably due to a narrower region of the eutectic in the former.View full abstractDownload PDF (2575K) -
Hisashi SUZUKI, Motohiro KANNO, Taku KITAYAMA1978 Volume 28 Issue 6 Pages 292-299
Published: June 30, 1978
Released on J-STAGE: July 23, 2008
JOURNAL FREE ACCESSA phenomenon that the density of β'-precipitates is not always unifbrm through the section of rolled sheet, . that is, the precipitates are often denser near the sheet surface was investigated in Al-Mg alloys containing 5 to 10%Mg. The rolled sheets were solution treated at 400°to 500°C and aged at 200°C for prolonged times. The phenomenon is partly related to the internal oxidation during soaking before rolling, because the oxides formed finely and densely near the surface act as nucleation sites for β'; and partly to the increased concentration in the effective quenched-in vacancies, being a function of solution treatment temperature and quenching rate. The β'-precipitation and age hadenability are enhanced by the appearance of the above phenomenon, leading to the ununiformity of aged sheets.View full abstractDownload PDF (3093K) -
Technical Committee On Aluminium Finishing The Jap1978 Volume 28 Issue 6 Pages 300-317
Published: June 30, 1978
Released on J-STAGE: November 05, 2008
JOURNAL FREE ACCESSDownload PDF (3018K)
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