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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 4
Displaying 1-8 of 8 articles from this issue
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Seiki NISHI1967 Volume 17 Issue 4 Pages 171-172
Published: July 31, 1967
Released on J-STAGE: October 30, 2008
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Yotaro MURAKAMI, Takashi KAGEYAMA1967 Volume 17 Issue 4 Pages 173-184
Published: July 31, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe effects of addition of 0.1 at. % of Be, Co, Ti, Zr, or Y on the precipitation of Al-5% Zn-2% Mg alloys were studied by tensile strength and electric resistivity and with transmission electron microscope.
In the low temperature ageing, the peak resistivity for zone formation decreased by the addition of Ti, Zr, or Y. The rate of clustering decreased by the addition of Zr, which would be due to the increase of density by vacancy sinks. Tensile strength increased by the addition of any of the above five elements, in particular, by the addition of Zr; it was due to the grain refining of the additional element.
On the other hand, in the high temperature ageing, the intermediate precipitates in the grains were made coarser owing to the additional element and lower quenching rate; it would be explained in terms of nucleation effects of clusters which had been formed during the quenching and at a very early stage of ageing at low temperature.View full abstractDownload PDF (2678K) -
Shigeo ZAIMA, Kenji TANI1967 Volume 17 Issue 4 Pages 185-190
Published: July 31, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe tapping (tapping for screwing) test for wrought aluminum alloys is reported in th paper. Three sorts of alloys, or 17S and 24S as typical alloys of high tensile strength and 56S as an anticorrosion alloy, were examined for tapping machinability such as tapping resistance, state of rough surface, accuracy of finished surface, etc.
The results obtained were summarized as follows.
The tapping torque was not affected by cutting speed of 5-10m/min in this experiment, but the torque at a constant rake angle slightly increased with the increase in tapping load. The torques varied according to the sorts of materials. Their values were arranged in ascending order of 24 S-F, 17 S-F, and 56 S-F, among which 24 S-F gave the most stable value, while the latter two gave unstable ones, having large deviation. It seemed that the state of finished surface was dependent upon rake angle and tapping load, but was independent of cutting speed; and there would be found out optimum tapping conditions for obtaining the best surface state. It was observed that the pitch of thread agreed with the tap within the limit of ever in measurement regardless of tapping conditions, and the angle of thread was larger by 30-60' than that of tap. The value of microhardness tended to increase up to about Hv=10-20 in the neighborgood of tapped surface.View full abstractDownload PDF (1097K) -
The studies on fabrication of ultra-fine wire of aluminum and aluminum alloys (2nd Report)Kazumasa ONO, Mikio NISHIHATA, Seiji KOBAYASHI1967 Volume 17 Issue 4 Pages 191-197
Published: July 31, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThese experiments were carried out for the production of aluminum ultra-fine wire for transistor lead by clothing it with copper and for studing its mechanical properties.
The results obtained were as follows:
(1) Pure aluminum ultra-fine wire produced by the method of clothing with copper was fully available for transistor lead wire, because its tensile strength was 12-13kg/mm2, its VHN was about 33, and its hardness was uniformly distributed over the whole.
(2) The desirable time for process annealing of the copper clad aluminum wire should be less than 1hr at 250°C or less than 1/2hr. at 300°C when the rate of cold drawing was above 80%.
(3) Intermetallic compound was formed on the boundary layer by heating for more than 2hr. at 250°C or more than 1hr. at 300°C and its hardness was higher than 500 VHN.View full abstractDownload PDF (1374K) -
Yoshiyasu ITO, Yoshimasa TOMINAGA, Yasuo WATANABE1967 Volume 17 Issue 4 Pages 198-211
Published: July 31, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSOn metallic mold casting of aluminum alloys, the air gaps formed between the mold surface and solidified layer have remarkable effects on the solidification rates of the alloys. The solidification rate and temperature distribution of aluminum alloy, AC8A in the metallic mold were determined to find the correlation between the air gap and casting conditions. The test results were compared with those calculated by electric analogue method.
The results obtained by the above tests were as follows.
(1) The heat transfer rate in the air gap was nearly 800-2000kcal/m2hr. °C within the scope of the above tests.
(2) The volume of air gap gradually increased with the progress of solidification until the thickness of solidified layer reached 10-15mm., where no further increase of the volume was observed.
(3) The volume of air gap was smaller when the solidification rate was lower in casting; that is, the volume was smaller when the mold had thicker wash coat, higher temperature, or thinner wall.
(4) Accordingly, the required total heat transfer rate (α2) between the mold surface and the solidified layer could be determined by measuring the heat transfer rate in gap aid the thermal coductivity of the wash coat on the mold.View full abstractDownload PDF (1788K) -
Ichiji OBINATA, Yoshimichi MASUDA, Sadahiko MITSUGI1967 Volume 17 Issue 4 Pages 212-224
Published: July 31, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSIn order to determine the effects of non-uniformity of oxide dispersion on the mechanical properties of sintered aluminum powder alloys, two series of the alloys containing the same amounts of oxide, having different uniformity of dispersion, were prepared by powder metallurgy process. The experiments were conducted mainly for the comparison of their ductilities.
Reduction of the uniformity resulted in the decrease of yield strength at room temperature, but in the marked increase of ductility for the alloys containing less than 7% (vol.) of oxide. The results of tensile tests were compared for the two series of the alloys up to 500°C. It was shown that the alloys of nonuniform dispersion had little dependency of ductility on temperature, but exhibited a large amount of work by tensile deformation in plastic region. Hardness of non-uniform dispersion alloys revealed higher thermal stability in the heat-treatment after cold rolling, as compared with that of uniform dispersion alloys having considerably high thermal stability as extruded material. The results of density measurement and fractographical observation of tensile fracture suggested that brittleness at high temperatures was closely related to the void formation due to gases released by the decomposition of hydrated aluminum oxide in the aluminum powder.
It is concluded that appreciable improvements in mechanical properties of these alloys can be expected by proper control of uniformity of oxide dispersion and also by preliminary degassing treatments of powder before compacting process.View full abstractDownload PDF (3009K) -
Study on the machining of magnesium alloy (1st Report)Takuichi MORINAGA, Shigeo ZAIMA, Masaji IIO1967 Volume 17 Issue 4 Pages 225-230
Published: July 31, 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSFor the purpose of discussing machinability of magnesium alloys, cutting tests were conducted on magnesium casting alloy AZ63, first of all. Also, concurrently with these tests, the same tests were conducted on zinc, which also belongs to close-packed hexagonal system as the above alloys.
These results of machinability were discussed in comparison with those of aluminum alloys, etc.
The following results were obtained.
Cutting resistance and force (unit net horsepower) were very small for both AZ63 and zinc, and in particular, the former material gave nearly half values of those of the latter. The cutting resistance of zinc corresponded to that of 11S, a kind of free cutting wrought aluminum alloy. The cut surfaces of the both materials were considerably well finished without roughness and there was no matter in chip treatment. There is a trouble that the chip of magnesium alloys, especially, is easy to fire in cutting; however, for AZ63 no risk of firing was found under various conditions through the experiments. So it may be concluded that these materials have very excellent machinability to resist high speed heavy cutting.View full abstractDownload PDF (1076K) -
1967 Volume 17 Issue 4 Pages e2
Published: 1967
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (27K)
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