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Volume 43, Issue 5
Displaying 1-9 of 9 articles from this issue
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Koichi TADA, Itaru TAJIMA, Atsumi OHNO1993 Volume 43 Issue 5 Pages 247-251
Published: May 30, 1993
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSStrips of 99.7% purity aluminum have been produced by open type, horizontal, heated mold continuous casting process (OSC). The strips are rolled by cold rolling, and the mean rolling pressure is measured. The influence of solidified structures on the surface condition and the precision of measurements of the rolled strip is examined. The surface of the sheets obtained, is extremely smooth and flat without any cracks. The thickness of the sheets is uniform irrespective of the rolling direction, when the strips have a unidirectionally solidified structure parallel to the casting direction. However, a lot of intergranular cracks form at the edge of the sheet, when the strips are composed of many crystals.View full abstractDownload PDF (944K) -
Toshiji MUKAI, Kenji HIGASHI, Shin TSUCHIDA, Shinji TANIMURA1993 Volume 43 Issue 5 Pages 252-257
Published: May 30, 1993
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe stress and ductility of some commercial aluminum alloys (1050, 3003, 3004 and 5182) have been investigated as a function of strain rate over the range from 1×10-3 to 3×103s-1 at room temperature. The nominal stresses at a strain of ε=0.105 for both 1050 and 3003 alloys increase with increasing strain rate, but the nominal stresses for both 3004 and 5182 alloys decrease with increasing strain rate in the low and intermediate ranges from 1×10-3 to 1×102s-1. The alloys showing the above negative strain rate sensitivity of stress in this strain rate range contain magnesium atoms in solute. Therefore, this behavior of stress in these alloys is possibly related to the interaction between magnesium atoms in solute and dislocations. Uniform elongations of alloys except a 1050 alloy show the maximum values in an intermediate strain rate range. Total elongations increase with increasing strain rate for all alloys investigated.View full abstractDownload PDF (1282K) -
Isao ITOH, Yasuo OTOGURO, Takao DOI, Syouji KIMURA1993 Volume 43 Issue 5 Pages 258-262
Published: May 30, 1993
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSEffects of addition of Sn and combined addition of Sn and other element (Cu, Mg, Zn, Ti, Si, Bi, Cr, Mn or Ni) to aluminum and surface roughness on the diffusion weldability of Si3N4 and aluminum alloys in the atmosphere were investigated. Welding surface was polished either with #800 grinding paper, or with 9μm diamond powder. Diffusion welding treatments were mainly carried out at 873K for 7.2ks under pressure of 2 and 4MPa. The weldability was evaluated by the shear fracture strength. The combined addition of Sn and Mg to aluminum produced the couple showing good weldability with the strength of 45MPa, while by the single addition of Sn the strength was only about 20MPa. The couple of Si3N4/Al-0.5Sn-1Mg showed the strength of 55MPa which was almost same strength as that of Al-0.5Sn-1Mg alloy. The above couple was fractured at the welding interface in the shear tension test. The thermal stress was found to be caused by the non-uniform distribution of Sn at the interface of the welded joint. The uniform distribution of Sn was obtained by smoothing rough joint surfaces and resulted in the released thermal stress.View full abstractDownload PDF (1295K) -
Toshiro KOBAYASHI, Mitsuo NIINOMI, Shinji HAKAMATA, Masashi MURAKAMI1993 Volume 43 Issue 5 Pages 263-268
Published: May 30, 1993
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSStatic and dynamic fracture toughness tests were carried out on Al-18mass%Si and Al-8mass%Fe powder metallurgy (P/M) alloys. The fracture mechanisms of the P/M alloys were investigated which was related to the microstructure. Both static and dynamic fracture toughness are greater in the Al-Si alloy than in the Al-Fe alloy. Crack propagates in the matrix or along the interface between matrix and particles according to the size of the particles under both static and dynamic conditions. Crack path which acrosses the coarse Si particles is also observed in the Al-Si alloy. The characteristic distance, l∗0, which dominates the fracture initiation is round from two through four times of the interparticle spacing of coarse particles under static conditions while that is equivalent to the distance between the fatigue precrack and the nearest coarse particle under dynamic conditions.View full abstractDownload PDF (1001K) -
Takashi ISHIKAWA, Masami KATO, Nobuki YUKAWA, Takashi JIMMA1993 Volume 43 Issue 5 Pages 269-274
Published: May 30, 1993
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSAn Al-Cu-Mg alloy is made by mechanical alloying process. The influences of the conditions of the mechanical alloying, compaction and extrusion on the superplastic behavior and microstructures of the material are investigated. While the mechanical alloying time longer than a certain time has no effect on the grain size, there is the most suitable condition of the mechanical alloying time to obtain high superplastic elongation. The grain size becomes fine with decreasing extrusion temperature and the obtained fine grain is stable even after the heat treatment and tensile test. The superplastic elongation of the mechanically alloyed material increases with decreasing the grain size. The material developed in this work is suitable for the actual use because this shows high tensile strength at room temperature as well as high superplastic elongation at a speed as high as that of the mechanical press.View full abstractDownload PDF (1026K) -
Shunzo AOYAMA, Hiroshi SUGITANI, Katsumi SAKAMOTO, Teruyoshi UMEMURA1993 Volume 43 Issue 5 Pages 275-280
Published: May 30, 1993
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSIn order to evaluate the resistance due to shrinkage of aluminum alloy die castings against ejection, the force required to pull the core slide from the casting and the change in casting's internal temperature were measured of hollow cylindrical die castings produced with different chill time. The core pull-out force measured was compared with the theoretical value in accordance with the plastic-elastic theory of shrinkage fit of a thick-walled cylinder. The calculated values agreed well with the measured ones. At a time of core pulling, a thin walled casting remained in a fully plastic state, whereas a thick walled casting was thought to be in a partly plastic state from the calculated values.View full abstractDownload PDF (829K) -
Michihiro TAGAMI, Setsuo ASO, Shoji GOTO, Kazuo KOIKE1993 Volume 43 Issue 5 Pages 281-284
Published: May 30, 1993
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSEffect of electroless Ni-P plating on the plane bending fatigue strength and crack propagation for an aluminum and an aluminum casting alloy (AC2B) was investigated using a uni-bending fatigue test machine at a cycle of 30Hz. Electroless Ni-P plating of the 20μm deposited film in thickness results in about 20 to 30% improvement of fatigue strength for an aluminum and the heat-treated AC2B casting alloy. An electroless Ni-P amorphous film has an effect to delay the nucleation of fatigue cracks and improve the fatigue strength.View full abstractDownload PDF (566K) -
Kunio ITO1993 Volume 43 Issue 5 Pages 285-293
Published: May 30, 1993
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (927K) -
Kazuo MATSUZAWA1993 Volume 43 Issue 5 Pages 294-295
Published: May 30, 1993
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (252K)
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