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Volume 8 (1958)
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Volume 8, Issue 3
Displaying 1-10 of 10 articles from this issue
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Shiro ISHIDA1958 Volume 8 Issue 3 Pages 3-4
Published: May 31, 1958
Released on J-STAGE: September 04, 2009
JOURNAL FREE ACCESSDownload PDF (666K) -
1958 Volume 8 Issue 3 Pages 4
Published: 1958
Released on J-STAGE: September 04, 2009
JOURNAL FREE ACCESSDownload PDF (73K) -
On solidification constant for pure aluminiumYoshinobu NAKAO1958 Volume 8 Issue 3 Pages 5-10
Published: May 31, 1958
Released on J-STAGE: September 04, 2009
JOURNAL FREE ACCESSWhen molten aluminium is cooled by water or mould, and a directional solidification is fixed, the relation between the solidification time (t) and the depth of solidified part (x) is shown by a formula x=q√t. The solidification constant (q) contains many factors as variables: they are temperatures of molten aluminium, coolingwater, mould, and thermal properties of solid and liquid aluminiums. The auther calculated the influences of these factors on the solidification constant, and the results were as follows.
(1) In the case of water cooling
The temperature of the molten aluminium had the most significant influence on the solidification constant, and the higher the temperature was, the smaller was the solidification which constant. The thermal conductivity of the solid alminium was the only factor increased the solidification constant.
(2) In the case of cooling by mould
The temperature of the molten aluminium had the most significant influence, in that the higher the temperature was, the smaller was the solidification constant as in the case of water cooling. The thermal conductivity of the solid aluminium and the heat diffusivity of the mould material were the two factors which decreased the solidification constant. It was made clear theoretically that in the case of the small heat diffusivity of the mould material or the low pouring temperature of aluminium, the solidification did not occured.View full abstractDownload PDF (758K) -
Takashi IKENO, Kizo SHIBATA1958 Volume 8 Issue 3 Pages 11-14
Published: May 31, 1958
Released on J-STAGE: September 04, 2009
JOURNAL FREE ACCESSChange of structure due to heating at 450° and 600°C of supercooled ingot castings of thealloys of high purity Al (99.99%), 1S (99.74%) and 2S (99.17%) and 0.1% Fe and 0.1% Si was investigated. Also, the effect of heating on 1S and 2S alloy ingots cast with tilting mold preheated at 300°C was investigated and the relation between the structure and surface patern after rolling and anodic oxidation was discussed.
The results obtained are summarized as follows:
(1) When the supercooled high purity Al ingots are repeatedly heated at 450°C for 30min., the apexes of columner crystals become gradually obtuser.
(2) In the specimen heated at 600°C for 30min. the columner crystals changed to free crystals, and when the heating is repeated the grain boundary migration occurs in the same way as the growth of recrystallized grains.
(3) Twin crystals which appear in the specimen heated at 600°C for 30min. are so stable against later heating that they influence the migration of neighbors grain boundary.
(4) In the supercooled ingots with 0.1% Fe or 0.1% Si added, little migration of grain boundary occurs even heated at 600°C for 30min.
(5) When the ingots of 1S or 2S alloys are heated by air furnace at 580°C the structure change by heating is found in the cross section of the ingot but not in the side surface. Hance the surface patterns after rolling and anodic oxidation do not change even by heating.View full abstractDownload PDF (2085K) -
Investigation of solutionizing of β phaseYasuji NAKAMURA1958 Volume 8 Issue 3 Pages 15-20
Published: May 31, 1958
Released on J-STAGE: September 04, 2009
JOURNAL FREE ACCESSThe phenomena during solutionizing of β phase were investigated by means of normal and iso-thermal differential dilatation and electron microscopy. A remarkable contraction was observed during the reaction, which was presumed to require longer duration for its completion from the dilatation curve. The curve of lower silicon alloy showed first a rapid contraction and secondly a slow contraction, while that of more silicon alloy showed only the second slow contraction. The first contraction seemed to be contributed by the solutionizing of secondary β phase proceeding only a few minutes at 440°C, and the second one caused by that of ternary β phase proceeded slowly for several ten hours at the temperature. The natural logarithm of the solutionizing velocity has a linear relationship to the reciprocal of holding temperature in °K. The activation energy of solutionizing of β is calculated as 48, 000cal/mol for secondary β and 20, 700cal/mol for ternary β.
The range of silicon content that precipitates the secondary β is 0.06% Si for aluminium-10% magnesium alloy and 0.03% Si and 0.25% Si for 7% magnesium alloy and 13% magnesium alloy respectivery.View full abstractDownload PDF (1138K) -
Takuichi MORINAGA, Shigeo ZAIMA, Kazuo KOSHIISHI1958 Volume 8 Issue 3 Pages 21-25
Published: May 31, 1958
Released on J-STAGE: September 04, 2009
JOURNAL FREE ACCESSThe authors repoted previously that the specific volume analysis could be applied to the industrial method for analysing the aging mechanism in aluminium alloys. In this paper, details of the experimental study are reported as a continuation of previous report, on the aging of three sorts of Al-Cu alloy, i. e. 3.116% Cu, 4.240% Cu and 6.200 Cu, the internal change of which was investigated well by H. K. Hardy and others, by means of specific volume analysis.
The experiments are pursued just like those in the previous report, that is, after being kept at 500-520°C for 30 minutes, the specimens are quenched in water and recieve the temperd aging for a long time at the prescribed temperature, and then the change of specific volume is pursued. And further the specific volume analyses are applied on the aging at raised temperature of the quenched specimens and the aging (at 20°C) of the rehardened specimens which are quenched into water from 200°C.
We appreciate that this research has been done at the expence of the Grant-in-aid of the Scholarship from the Institute of Light Metal Foundation.View full abstractDownload PDF (671K) -
On the corrosion of some aluminium alloys in alcohol and acid solutionTakuichi MORINAGA, Shigeo ZAIMA, Motoo KAGAMI1958 Volume 8 Issue 3 Pages 26-33
Published: May 31, 1958
Released on J-STAGE: September 04, 2009
JOURNAL FREE ACCESSAs an outline of the corrosion resistance of 1S, 2S, 3S and 52S in brandy had been reported in the previous paper a new experiment on to corrosion resistivity alcohol and acid was carried out for the purpose of obtaining the data to discuss the previous resul. The details of the experiment are as follows:
(1) A alcohol is diluted nearly equal to the alcohol concentration of raw brandy (or wine). Then, the specimens are dipped in this solution and the corrosion resistance in alcohol solution is examined.
(2) The specimens are dipped in the acid solution which is equal to the total acidity of the raw brandy (or wine) and their corrosion resistance is examined as the above.
(3) Then, the same experiments as the above are made in the mixed solution of alcohol and acid of the same alcohol concentration as the raw brandy (or wine).View full abstractDownload PDF (984K) -
Quantitative analysis of Cr, Fe and Si in Al-Cr mother-alloyToyoji USHIODA, Osamu YOSHIMURA, Masahiro SADA1958 Volume 8 Issue 3 Pages 34-37
Published: May 31, 1958
Released on J-STAGE: September 04, 2009
JOURNAL FREE ACCESSIn case of quantative spectro-analys with solution type samples, many apparatuses and processes have been developed, because of its several advantages compared with solid type samples.
In the previons report, we explaned our new method with carbon electrode which was not affected by its porosity and could be used in practcal routine work.
This time, some improvement was made on the electrode-set and the spectroanalysis was tried on Cr, Fe and Si in Al-Cr mother-alloy.
Results obtained are as follows;
Element Content range Mean deviation Stamdard deviation
(%) (%) (%)
Cr 1.6-2.2 5.48 3.61
Fe 0.3-1.1 8.27 4.94
Si 0.07-0.15 13.83 11.54
In these results, it is considered that analitical accuracy of Cr and Fe is practically satisfactory, but that of Si is not satisfactory.View full abstractDownload PDF (750K) -
Kinetics of reaction of commercial pure titanium and titanium alloys with O2, N2 and N2 (2nd Report)Desorption of hydrogen from Ti-5Al alloy and Ti-5Al-1Cu alloyHidetake KUSAMICHI, Yosiro YAGI, Toru YUKAWA, Tadao NODA1958 Volume 8 Issue 3 Pages 38-41,20
Published: May 31, 1958
Released on J-STAGE: September 04, 2009
JOURNAL FREE ACCESSA series of experimental studies was performed on the kinetics of reaction of commercially pure Ti and Ti alloys with the gas phase H2 O2 and N2, and the Report 1 already dealt with the desorption of H2 from commercially pure titamium. This paper deals with the investigation on the desorption of H2 from Ti-5Al alloy and Ti-5Al-Cu alloy. Sponge titanium prepared by the Kroll process and alloying element were arc melted by the consumable electrodedouble-melting method, and the ingot was forged at 900° and machined to a rod of 7m/m in diameter, which was annaealed in argon atmosphere at 700°C and then degassed in vacuo of 1×10-4mmHg at 700°, 750, 800, 850 and 900°C. The evolved hydrogen was collected by means of a Bentells pump and measured by micro-Oelsat gas analysier. It was found that the logarithms of the concentration of hydrogen in metals were decreased in linear relation with time at any teperature in the same way as the case of commercially pure titanium, and from these relations the diffusion constaut D were calculated by Al Demarezs formula. Temperature dependences of D in the titanium alloys are offered as follows:
D(Ti-5Al)=47.7exp(-36, 800/R·T)
D(Ti-5Al-1Cu)=0.15exp(-25, 250/R·T)View full abstractDownload PDF (638K) -
Takuichi MORINAGA, Ishi MIURA, Tetuya TAKAAI1958 Volume 8 Issue 3 Pages 42-52,10
Published: May 31, 1958
Released on J-STAGE: September 04, 2009
JOURNAL FREE ACCESSOxidation of Ti-Fe alloys at high temperature was investigated mainly by measuring the weight change due to the formation of oxidation layers. Measurements were made on a specimen cross section and the authors have considered on the hardness penetration in the time of oxidation.
The specimens were Kroll titanium, 1%Fe, 2%Fe. 4%Fe and 8%Fe alloys and heated in the air at 600, 700, 800 and 900°C.
Generally speaking, parabolic rate law, (Δm)=Kp·t+C, was applicable to the oxidation of Kroll titanium and Ti-Fe alloys in the range 600-900°C.
Authors have gained the value of the parabolic oxidation rate constant for all the specimens at each oxidation temperature. The relations between the logarithms of experimentally determined Kp and 1/T were straight lines except the oxidation of 4%Fe and 8%Fe alloys.
Activation energies were calculated from the diagram, they were 58700, 66000 and 57000cal/mol respectivery for Kroll titanium, 1%Fe and 2%Fe alloys.
Hardness penetration was deeper as the alloying element increases for the same oxidation temperature and time.
X-ray analysis of the oxidation layers showed only strong reflections of rutile even for 8%Fe alloy which was oxidized at 900°C for 25 hours.View full abstractDownload PDF (2044K)
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