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Volume 17 (1967)
- Issue 6 Pages 339-
- Issue 5 Pages 257-
- Issue 4 Pages 171-
- Issue 3 Pages 117-
- Issue 2 Pages 63-
- Issue 1 Pages 1-
Volume 17, Issue 3
Displaying 1-7 of 7 articles from this issue
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Yoshinobu NAKAO1967 Volume 17 Issue 3 Pages 117-118
Published: May 30, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (351K) -
Ichiji OBINATA, Noboru OHNEDA, Yo TAKEUCHI1967 Volume 17 Issue 3 Pages 119-124
Published: May 30, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSAl-4%Fe, Al-12%Ni, Al-3%Mn, and Al-40%Cu alloys were solidified in the magnetic field of 19-74K oersted. The structure of solidified ingot was observed as follows:
(1) It was found that the effects of the magnetic field on the structure of Al-Fe alloys was most remarkable. The primary crystals of FeAl3 in the eutectic matrix were regularly arranged in layers in perpendicular to the magnetic flux. Both of aluminum and FeAl3 are paramagnetic materials; however, the susceptibility of the latter is fairly higher as compared with that of the former as seen in Fig. 1. Consequently, the primary crystals of FeAl3 revolved to the preferred direction in the molten bath by the action of the magnetic field.
(2) The direction of the crystal growth of FeAl3 was almost perpendicular to the magnetically predominant direction of that crystal; the former was found to be [001] of monoclinic system and the latter was [010].
(3) Each of the arrangements of primary crystals of NiAl3, MnAl6, and CuAl2 was not so regular as that of FeAl3. But the growth of primary crystals of the each alloy was strongly promoted to be in coarse size. It is suggested that these phenomena resulted from the prevention of convection current in the molten bath by the magnetic force.View full abstractDownload PDF (1471K) -
on the fatigue of welded aluminum alloys (1st report)Yutaka ISHIKAWA, Susumu YOSHIDA1967 Volume 17 Issue 3 Pages 125-131
Published: May 30, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThis paper reports the fatigue strength of welded aluminum alloys, mainly based on Al-Zn-Mg systems.
The experiments were conducted on (1) The relation between the method of butt welding and the fatigue strength of parent alloys; (2) The comparison of stress concentration factors between the welds and parent alloys and the study on notch effect; (3) The relation between the cause of large deviations in fatigue strength of welds and surface effect; and others.
The results obtained were as follows.
(1) The fatigue strength of welds with bead was about 50-60% of that of parent alloys (55-65% in case of one side welds and 50-55% in case of both side welds). However, when the bead was removed, the fatigue strength was about 70-75% of that of parent alloys.
(2) The welds can be considered to be notched parent alloys in a broad sense and the reduction factor of fatigue strength of the welds was compared with that of notched parent alloys. Welds without beads corresponded to the notched parent alloy having stress concentration factor of αk=1.68. Welds with beads corresponded to the notched parent alloy having αk=2.10 in case of one side welds or αk=3.10 in case of both side welds.
(3) The deviations in fatigue strength of welds had a close relation with the surface roughness of specimens as well as that of parent alloys. When the bead zone or surface of specimen was polished to the smoothness of within 1.0μ, the range of the said deviations markedly decreased accompanied with the increase of fatigue strength.View full abstractDownload PDF (875K) -
on the fatigue of welded aluminum alloy (2nd Report)Yutaka ISHIKAWA, Susumu YOSHIDA1967 Volume 17 Issue 3 Pages 132-140
Published: May 30, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThis paper reports the fatigue strength of welded aluminum alloys (mainly based on Al-Zn-Mg systems) having weld defects and various bead profiles.
The studies were made on (1) The effects of weld defects (mainly lack of penetration) on fatigue strength; (2) The effects of bead profiles on fatigue strength; and others.
The results obtained were as follows:
(1) In case of welds with bead, lack of penetration, even though the lack was more than a half of the plate thickness, had almost no effects on the fatigue strength under repeated bending stress.
(2) In case of welds without bead, cracks originated from the root of lack of penetration under repeated bending fatigue test and the lack of penetration gave remarkable effects on the fatigue strength of welds under repeated bending stress. However, the degree of effects depended upon the material of parent alloy or the combination of the parent alloy with filler wires. The fatigue strength of Al-Mg alloy welds decreased in parabolic curve with the increase of the depth of lack of penetration. However, in Al-Zn-Mg alloys, the fatigue strength did not decrease for the lack of penetration of about 1mm. When Al-Mg alloys were used for filler wires (or about 2.5mm. When Al-Mg-Zn alloys were used for filler wires). When the lack increased more than the above values, the fatigue strength decreased in parabolic curve with the same gradient as that in Al-Mg alloys.
The critical range of lack of penetration had no effects on the fatigue strength, but it depended upon the composition of the filler wire.
(3) Bead profiles had remarkable effects on fatigue strength; the fatigue strength linearly decreased with the increase of root angle of the bead in the range of 20-50°, but the effects on the strength were very little when the angle was without the above range.View full abstractDownload PDF (1834K) -
Shigeo ZAIMA, Masamichi HIRONO1967 Volume 17 Issue 3 Pages 141-147
Published: May 30, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSSolubility of manganese in aluminum decreases with the drop in temperature; for example, it is 1.82% at eutectic point of 685°C, and 0.36% at 500°C. However, it is known to be independent of the effects of heat treatment. It is expected that the addition of manganese, having low solubility in aluminum, will improve machinability, since the addition of lead, which is insoluble in aluminum, improves machinability of wrought aluminum alloy such as 11S. In these studies, 3 sorts of aluminum-manganese alloy castings were produced, according to Mn content in the range of 1.5-5.5% for conducting turning tests. The relation between Mn content and machinability was examined by the observation of cutting resistance, roughness of surface, built-up edge, chip treatment, etc. The results obtained were as follows. Cutting resistance was much lower than that of pure aluminum at the addition of 1.5% of Mn, but gradually decreased with the higher content of Mn. However, surface roughness was more deteriorated and the growth of built-up edge was more active when Mn content was higher than 1.5%. Accordingly, satisfactory effects of higher contents of Mn were not observed in the results of machinability, even when mixed phase of α+β of Mn was contained in the alloy.View full abstractDownload PDF (1478K) -
Shigeru MATSUO, Michio NISHIDA, Harero IWAMURA1967 Volume 17 Issue 3 Pages 148-151
Published: May 30, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSIt is well known that aluminum alloy die-castings contain a large amount of gases. However, there have been seldom reports on the content and composition of those gases.
In this experiment, vacuum fusion method was applied to the determination of gas content in a certain aluminum alloy die-castings and hydrogen content in the gas was determined by measuring pressure difference between before and after heating a palladium tub econnected to gas analyzer.
The present results showed that the die-castings contained gases of 20-30cc NTP/100g Al, and 70-80% of the total volume hydrogen whose source was found to be the lubricant for sleeve and die.View full abstractDownload PDF (501K) -
Light Metal Smelters Association, Aluminium Technical Committee1967 Volume 17 Issue 3 Pages 152-163
Published: May 30, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (1320K)
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