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Volume 15 (1965)
- Issue 6 Pages 333-
- Issue 5 Pages 273-
- Issue 4 Pages 201-
- Issue 3 Pages 139-
- Issue 2 Pages 83-
- Issue 1 Pages 1-
Volume 15, Issue 4
Displaying 1-8 of 8 articles from this issue
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Toyoji USHIODA1965 Volume 15 Issue 4 Pages 201-202
Published: July 31, 1965
Released on J-STAGE: October 30, 2008
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Yoshikazu HORIGUCHI, Shunzo KATAYAMA1965 Volume 15 Issue 4 Pages 203-208
Published: July 31, 1965
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSSulfur dioxide gas was passed through an aqueous suspension containing red mud, a by-product of alumina manufacture by the Bayer process, and the following results have been obtained:
(1) Dissolutions of Na, Si and Al cease practically in about 10min.
(2) Sodium aluminosilicate in the red mud is thoroughly decomposed.
(3) The rates of dissolution of Na, Si and Al are respectively estimated to be 100, 80 and 60%, however, those of Fe and Ti are very little.
(4) There is little effect of temperature on the dissolution of the components of the red mud.
(5) With increase in a ratio of red mud to water, the quantities of the components of the red mud dissolved are increased, however, the rates of dissolution of Na, Si and Al remain unchanged and those of the other components are decreased.
(6) The higher the concentration of the sulfur dioxide gas, the larger the quantities of the components of the red mud dissolved, and the decomposition of the insoluble sodium aluminosilicate can be almost taken place with 10% sulfur dioxide gas.
(7) From the experimental results mentioned above, the optimum conditions to recover Na, Al and Fe from the red mud by the present process have been determined.View full abstractDownload PDF (620K) -
On the relation between the geometry of countersink and the chisel edge angle of drillShigeo ZAIMA, Akiyasu YUKI, Osamu HORIUCHI1965 Volume 15 Issue 4 Pages 209-217
Published: July 31, 1965
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSWhen aluminium sheet is countersunk with a twist drill, it is well known that it is not easy to obtain a circular countersink but an odd numbered polygonal holes, such as the rounded triangular, pentagonal or heptagonal hole. It is due to so-called "the walking phenomenon of drill" which gets into trouble not to be neglected in practice from the viewpoint of machining accuracy, finished appearance and others.
In this paper, the influence of chisel edge angle of drill on the geometry of countersink is examined and the drilling conditions to obtain the circular hole are searched in the case of countersinking sixsorts of aluminium sheets, e. g., 2S-H, 3S-H, 14S-O, 52S-H, 61S-H and G4-H.
As the results, chisel edge angle was found to heve a large affect on increasing "the out of roundness". And the latter In the case of using high-tension hard alloy, such as, 52S-H and G4-H, the countersink is enarly circular and has smallusing roundness, even if the chisel edge angle is considerablly large (in this experiment, 140°), however, in the case of low-tension soft alloy, such as, 2S-H and 3S-H, the countersink has small out of roundness, unless the chisel edge angle is small (in this experiment, not more than 120°).
This study was conducted uuder the partial financial support of the fund furnished by Scholarship Committee of the Institute of Light Metals for which we feel deeply grateful.View full abstractDownload PDF (1093K) -
Akihiko KAMIO, Umeo HONMA, Shigeo OYA1965 Volume 15 Issue 4 Pages 218-224
Published: July 31, 1965
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThis is the second progressive report on the work of crystallization of aluminium and its alloys succeeding to the preceding macroscopic work "Formation of Crystal Structures in Pure Aluminium." A particular interest is turned to the crystallizing manner of the primary aluminium-rich solid solution in the hypo-eutectic aluminiumsilicon alloy. Droplets of the alloy were quenched in water at various progressive stages in the freezing range to impede further dendritic growth. Several variables particularly set up to represent the dendritic growth were determined on the structures of these droplets as functions of undercooling.
The nucleation is completed at the undercooling down to 0 to 5°C after the course of dendritic growth. The macroscopic percentage of crystallizing solid has further curvature than that predicted from Scheil's equation. In other words, in the initial stage of freezing at the undercooling down to approximately 15°C most of the primary solid is formed, from this time to the eutectic start crystallizing is retarded, and the α-solid solution in the eutectic mixture crystallises in the mode of dendritic growth of the primary dendrites already formed. A particular Skelton crystal is formed just before the nucleation. All the dendrite arms reach the maximum length during the temperature fall approximately 5°C from the nucleation. Volumetric increase of dendrites depends on the discontinuous course i.e. expansion of the dendrite cells and fusion of neighboring cells rather than the linear growth toward the direction of arms. Such a type of growth is completed at the undercooling down to 15 to 20°C and is repeated again during the eutectic freezing.View full abstractDownload PDF (1959K) -
Riei ICHIKAWA, Reiko SAITO1965 Volume 15 Issue 4 Pages 225-229
Published: July 31, 1965
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe distribution of beryllium in the surface part of solid magnesium alloys containing 0.005% beryllium after being heated at 400°, 500°and 620°C in air was studied in details by chemical analysis, and further, the effects of heating atmosphere on the change of the distribution of beryllium in the surface part of samples were also researched.
Results obtained are as follows:
1) The enrichment of beryllium is found in the superficial layer within the depth of 10 micron from the surface and it seems that the surface is not formed by simple layer of beryllium or beryllium oxide in spite of the enrichment of beryllium in the surface part.
2) The effect of heating atmosphere, such as nitrogen, carbon dioxide and water vapour, on the behavior of beryllium in samples is that the enrichment of beryllium in the surface layer after being heated in nitrogen is not so much as that of beryllium by being heated in air, the enrichment is found scarcely after being heated in carbon dioxide and marked enrichment of it for the surface is found after heating at 600° in water vapour, but is not so at 400°C.View full abstractDownload PDF (1094K) -
Goro ITO, Seiichi IKEDA, Shigeo OHASHI, Fumio SAWAYANAGI1965 Volume 15 Issue 4 Pages 230-240
Published: July 31, 1965
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe effect of temperature, pressure and impurities present in carbon dioxide gas on the corrosion of magnesium alloys for gas cooled reactors were studied. Test alloys were magnesium alloy with a small addition of aluminium and beryllium, i. e. so-called magnox AL-80 alloy.
The results of tests conducted in carbon dioxide gas at the temperature of 400-600°C, at the pressure of 1-100kg/cm2, under the stress of 0-0.146kg/mm2 and at the flow rate of 0-104cc/min, were summerized as follows:
1) The penetration rati of magnox alloy in static carbon dioxide gas was about 6-8×10-4mm/year and 1-4×10-3mm/year at a temperature of 400°C and 500°C respectively, and the rate increased with the increment of testing gas pressure from 1kg/cm2 to 50kg/cm2.
2) The activation energy of the oxidation reaction of the alloy in carbon dioxide at the pressure of 50kg/cm2, calculated from an Arrhenius' plot of the experimental data, was 21, 580cal/mol.
3) The presence of oxygen, water vapour up to 2% and/ nitrogen up to 5% in carbon dioxide did not affect the corrosion behavior of the test specimen, however, the increase in corrosion rate and occurance of blister type corrosion was noted when the amount of water vapour exceeded 5% of carbon dioxide.
4) The formation of intergranular cavities or oxidation were not observed in the magnox alloy when heated in carbon dioxide gas at the temperature of 500°C even under stressed condition.
5) The corrosion rate of the alloy in flowing carbon dioxide at the flow rate of 100-500cc/min was about 2 times faster than that of in static gas. This effect cannot be solely attributed to the production of carbon monoxide during reaction, because the equibulium constant for the reaction of Mg+CO2=MgO+CO at the temperature of 400°C is about 5.46×1023 and hence the minimum percentage of CO2 in CO+CO2 mixture necessary to oxidize magnesium is estimated as only 5.5×10-22%. It is rather suspected that the vaparization of magnesium may play a role for the increase of metal loss of specimens at a high flow rate.View full abstractDownload PDF (3450K) -
On the electric discharge machinability in cutting off of titaniumShigeo ZAIMA, Takeshi HIRAYAMA, Shingo KATO1965 Volume 15 Issue 4 Pages 241-249
Published: July 31, 1965
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSThe electric discharge cutting machinabilities of titanium and its alloys are searched in comparison with the machinabilities of mild steel, brass, beryllium bronze, aluminium (2S) and others by the Lazarenko-circuit and the rotating electrode made of brass disk. In this paper, the electric discharge cutting machinability is discussed by the time required for cutting, that is, the necessary time to cut unit thickness and unit length in sec/mm-mm.
The results are summarized as follows:
1) There exists the most effective cutting condition relating to working current.
2) The electric discharge cutting machinability of titanium alloy is better than that of mild steel, and there are no differences in the machinability, however, Ti-8% Mn alloy has the best machinability and the machinability gets worse in the order of Ti-5% Al alloy, titanium and Ti-2% Al-2% Mn alloy.
3) On the cutting solution for titanium, machine oil shows the highest efficiency, followed by kerosene by light oil and then water in the rear.
4) The width of cutting slit is slightly larger than the thickness of electrode disk and is in the range of 1.4-1.6 times in titanium.
5) The roughness of the cutting surface is in 6-10μ and may be said the good surface.
6) The cutting efficiency increases in the raise with the source voltage and the source ampere, but there exists the most effective condition in the condenser capacity and, in this experiment, it is in about 200μF.View full abstractDownload PDF (1024K) -
[in Japanese]1965 Volume 15 Issue 4 Pages 250-262
Published: July 31, 1965
Released on J-STAGE: October 30, 2008
JOURNAL FREE ACCESSDownload PDF (1315K)
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