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Volume 29, Issue 9
Displaying 1-9 of 9 articles from this issue
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Kensuke KURIHARA1979 Volume 29 Issue 9 Pages 375-376
Published: September 30, 1979
Released on J-STAGE: October 30, 2008
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Hitoshi TASHIRO, Shin-ichiro FUJIKAWA, Ken-ichi HIRANO1979 Volume 29 Issue 9 Pages 377-383
Published: September 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe coarsening behavior of Ge precipitates in the matrix and near the precipitate-free zone (P.F.Z.) along the grain boundary in an Al-3.46wt% Ge alloy was electron microscopically investigated. The coarsening data of the Al-Ge alloy aged at 523 and 573K were analyzed on the basis of the Lifshitz-Wagner theory on diffusion controlled coarsening. The coarsening kinetics of the Ge precipitates in the matrix follows the time-law predictions of the thoery. However, pronounced departure from t1/3 kinetics is found near P.F.Z. The number density of the Ge precipitates near P.F.Z. and the width of P.F.Z. were measured as a function of aging time. The particle-matrix interfacial free energy was determined.View full abstractDownload PDF (1034K) -
Shigeo ZAIMA, Yasuo SUZUKI, Biing Hwa YAN1979 Volume 29 Issue 9 Pages 384-390
Published: September 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDry facing tests on the discs 150mm dia. of aluminum alloy diecastings (ADC3) and aluminum plates (1100-H18) were carried out to achieve optimum facing conditions for flat and uniform surface finish. Inward facing of the diecastings with light depth of cut, moderate feed and high facing speed results in little built-up edge and excellent surface finish. Excellent surface finish of the pure aluminum discs is hardly obtained by usual facing. A combination of heavy roughing and reverse facing ensures adequate surface finish.View full abstractDownload PDF (1593K) -
Shigeo ZAIMA, Yasuo SUZUKI, Takahide IEKUMO1979 Volume 29 Issue 9 Pages 391-396
Published: September 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSWear of high speed steel tools in wet cutting of Al-Si castings AC3A using spindle and machine oils is investigated. The tool wear, in particular, so-called grooving wear is encountered more considerably in wet cutting than in dry cutting. The grooving wear occurs heavily in the tool face and lightly in the side flank side in wet cutting. Although the grooving wear is accelerated with prolonged cutting time, the cutting resistance and the cutting temperature remain unchanged. Other alloys such as AC4C, AC4D, AC8A and AC8B also have same wear characteristics.View full abstractDownload PDF (994K) -
Makoto TSUKUDA, Kumio TAKADA, Koichi OZAKI1979 Volume 29 Issue 9 Pages 397-402
Published: September 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSVariables in the ring compression test concerning the friction factor (m) such as specimen size, thickness of lubricant film, surface roughness of specimen and die, temperature difference between specimen and die, and compression speed were examined using 2014 alloy. The surface roughness and the thickness of film have the most important effect on the friction factor, and the other variables have a little effect. The minimum thickness of the lubricant film to maintain lubricity corresponds to a half of the sum of roughness on the die and specimen.View full abstractDownload PDF (851K) -
Makoto TSUKUDA, Kumio TAKADA, Koichi OZAKI1979 Volume 29 Issue 9 Pages 403-409
Published: September 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSRing compresion tests were conducted to evaluate lubricities of 20 kinds of lubricants for hot forging of 2014 alloy at 250° to 450°C and 10 to 50% reduction of height. The lubricity was evaluated by comparing the respective friction factors. The lubricants dispersed in oil are spray coated on the die at elevated die temperatures more successfully than those in water or emulsion type lubricants. High purity and grain finess of graphite and properties of the base oil are important for lubricity of a colloidal graphite in oil type lubricant. Several types of lubricants reasonably selected are successfully used for aluminum precision forging.View full abstractDownload PDF (1318K) -
Toshiyasu FUKUI, Hiroshi IRIE, Satoshi KIMURA, Zen-ichi TANABE1979 Volume 29 Issue 9 Pages 410-417
Published: September 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe behavior of zinc during brazing and the effect of zinc distribution on corrosion of aluminum heat exchangers were studied. Zinc in the A7072 alloy is reduced more remarkably by brazing in the lowered atmospheric pressure. The zinc loss in fin stocks is only caused by vaporization during brazing, and that in clad tubes is caused both by vaporization and diffusion towards a core material. Zinc-bearing alloys such as A7072 are successfully used as an outside fin stock and an inside inner-clad tube to improve the resistance to corrosion. Brazing under normal pressure is recommended rather than in vacuum on the viewpoint of the residual content and distribution of zinc in the brazed products.View full abstractDownload PDF (1726K) -
Yoritoshi MINAMINO, Toshimi YAMANE1979 Volume 29 Issue 9 Pages 418-427
Published: September 30, 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (1066K) -
1979 Volume 29 Issue 9 Pages ivc
Published: 1979
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (79K)
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