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Volume 55, Issue 5
Displaying 1-7 of 7 articles from this issue
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RESEARCH REPORT
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Yoshihiro NAKAYAMA, Shigeki NAKANISHI2005 Volume 55 Issue 5 Pages 199-203
Published: 2005
Released on J-STAGE: February 24, 2006
JOURNAL FREE ACCESSThe effects of pre-aging conditions on the two-step aging behavior of a 6063 aluminum alloy, containing less than 1.0mass% Mg2Si, were investigated mainly by electrical resistivity, differential scanning calorimetric (DSC) measurements and tensile test. The pre-aging treatments give both the positive and negative effects on the proof stress after the two-step aging treatment, suggesting that the boundary temperature of these positive and negative effects is about 300 K. Measurement results of electrical resistivities and DSC indicate that the formation of the cluster and G. P. zones during the pre-aging result in these positive and negative effects.View full abstractDownload PDF (653K) -
Keizo SAKURAI, Takeshi SAWAI, Linying LI2005 Volume 55 Issue 5 Pages 204-209
Published: 2005
Released on J-STAGE: February 24, 2006
JOURNAL FREE ACCESSIn this study titanium nitride coated high speed steel drills of diameter 0.3 mm are employed to clarify the behaviors of titanium coated micro drill during the drilling of minute holes, the geometrical relationship between the cutting edge and feed, wear of the cutting edge, chip shape, cutting edge movement in quick stop test and burr shape are investigated. Results reveal that a plane about 10 μm in diameter exist at the cutting edge of a micro drill at the portion connecting the face and the flank, and that the edge of this plane is responsible for the cutting action. The cutting mechanism is indicative of the resulting large negative rake angle created across the entire cutting edge which as is evident in the study greatly influences chip shape, cutting edge wear and peeling off of the coating layer.View full abstractDownload PDF (1346K) -
Takeshi SHINODA, Kazutoshi ISHIKAWA, Hiroaki TAKEGAMI2005 Volume 55 Issue 5 Pages 210-215
Published: 2005
Released on J-STAGE: February 24, 2006
JOURNAL FREE ACCESSFriction welding technique performs superior characteristics on mechanical properties and on production performances. However, the application of this technique is limited in joining of round bar materials due to the lack of positioning control capability. This limitation can be overcome by introducing recent servo system. This study is carried out to clarify the effects of process parameters on mechanical properties of positioning controlled joints of aluminum alloy. A6061 rods with square cross section. The positioning controlled joining was successfully performed. The mechanical properties of them are almost equivalent to the joints fabricated by conventional friction welding process, when sufficient upset distance is applied. Defects of imperfect joining are observed at the corner of the joints with square cross section, with the upset distance is insufficient. Higher upset load makes a better contact area at the weld interface resulting in narrower softened zone and larger upset distance eliminating weld imperfection.View full abstractDownload PDF (1473K) -
Seiichi MASA, Shin-ichi MATSUOKA, Toshiro YAGO2005 Volume 55 Issue 5 Pages 216-221
Published: 2005
Released on J-STAGE: February 24, 2006
JOURNAL FREE ACCESSWear resistance of duplex hard-coated die for aluminum extrusion are investigated. Nitrided layer of duplex hard-coat was prepared by gas nitriding, plasma ionic nitriding or plasma radical nitriding method, and the 3 μm hard coat films, CrN, TiN or TiAlN was by arc ion plating on the nitrided layer. Hardness, friction coefficient, critical load and roughness of duplex hard-coated specimens (SKD61) were observed before and after oxidation at 500°C or 650°C, atmosphere, 5h. Hardness of coated area of die before extrusion and after removal of adhesive aluminum were compared. Hardness of duplex hard-coat and single hard-coat were also compared. In the case of single hard-coated die which critical load was under 30 N, hard-coat in the front bearing area was deteriorated. On the contrary, duplex hard-coat which critical load was over 60 N, was hardly changed after 5 extrusions. Duplex hard-coated dice showed higher wear and oxidation resistance in comparison with dice singly hard-coated because the hardness of nitrided layer was nearly unchanged after heating at atmosphere.View full abstractDownload PDF (1401K) -
Tadashi MINODA, Mineo ASANO, Hideo YOSHIDA2005 Volume 55 Issue 5 Pages 222-226
Published: 2005
Released on J-STAGE: February 24, 2006
JOURNAL FREE ACCESSInfluence of increasing silicon and manganese content on the paint bake response and the bendability of the Al-1.0mass%Si-0.5mass%Mg-0.1mass%Mn-1.0mass%Fe alloy sheets was investigated in comparison with the reference alloy of Al-1.0mass%Si-0.5mass%Mg-0.1mass%Mn-0.1mass%Fe. When the silicon content was 1.2mass%, the paint bake response became almost the same as the reference alloy. The alloy containing 0.3mass% Mn also showed almost the same paint bake response. The bendability became lower with the increasing of Si and Mn contents. But the bendability of the alloy containing 1.2mass% Si was better than that of the alloy containing 0.3mass% Mn. It was proposed that cracks occur and propagate by micro-voids around second phase particles and shear bands which were formed during bending. With increasing of Si and Mn contents, it was considered that the shear bands were easily formed by bending, and then the bendability were decreased. In addition, it was also considered that the bendability of the manganese increased alloy became lower with increasing of second phase particles.View full abstractDownload PDF (1854K) -
Pizhi ZHAO2005 Volume 55 Issue 5 Pages 227-232
Published: 2005
Released on J-STAGE: February 24, 2006
JOURNAL FREE ACCESSPaint bake response and bendability in Al-0.6mass%Mg-0.8mass%Si alloy sheets with Mn contents: 0, 0.10, 0.19mass%, solutionized at 833K and preaged at 353K, were investigated. It is found that the paint bake response becomes higher and the bendability becomes better with the increase of Mn contents. The relationship between the paint bake response and Mn contents can be explained by assuming that amount of Si in solid solution in matrix increases as additional Mn promotes the transformation of β-AlFeSi phase compounds to α-Al (Fe · Mn) Si phase compounds during homogenization. The reason for better bendability with Mn addition is as follows: 1) formation of shear bands tended to be inhibited by the refined grain size and the increased Mn dispersoids, and 2) for the spherical α-Al (Fe · Mn) Si phase compounds, it was more difficult to form voids in comparison with the needle shaped β-AlFeSi phase compounds on the boundary between them and matrix.View full abstractDownload PDF (1827K)
LM REVIEW
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—New aspect of multi-ferroics—Yasubumi FURUYA, Teiko OKAZAKI2005 Volume 55 Issue 5 Pages 233-241
Published: 2005
Released on J-STAGE: February 24, 2006
JOURNAL FREE ACCESSDownload PDF (2751K)
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