巻号一覧
21 巻, 10 号
選択された号の論文の7件中1～7を表示しています
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山根 寿己1971 年 21 巻 10 号 p. 625-627
発行日: 1971/10/30
公開日: 2008/07/23
ジャーナル フリーIn order to explain the effects of Fe and Mo on the formation of ω-phase of Ti-Cr system alloys, the ω-phase formation was investigated by measurements of hardness, Young's modulus, and internal friction of Ti-Cr alloys, in which a part of Cr had been substituted by Mo or Fe. The valence electron atom ratio (e/A) of the alloys was higher than 4.14.
Principal results obtained by experiments were as follows.
(1) Even in the alloys having a valence electron atom ratio of higher than 1.14, ω-phase was formed by tempering after quenching frow β-region.
(2) Asimilar formation of ω-phase was also observed in Ti-Cr alloys in which a part of Cr had been substituted by Mo or Fe.抄録全体を表示PDF形式でダウンロード (796K) -
竹内 寛司, 小林 啓行1971 年 21 巻 10 号 p. 628-638
発行日: 1971/10/30
公開日: 2008/07/23
ジャーナル フリーIn general, the maximum extrusion pressure in hot extrusion depends on yield strength, billet diameter, billet length, extrusion ratio, extrusion temperature, and extrusion rate.
The object of this work was to derive a formula for calculating the maximum extrusion pressure as a function of the above factors in hot extrusion of round aluminum rods.
A number of extrusion experiments were conducted and an empirical formula was derived by analysis of the experimental results.
Since the experiments were done using 600 ton vertical type extrusion press with has the capacity of production scale, it could eliminate the scale effect usually encountered by small size experiments mainly due to the small heat capacity.
The yield strength having a great effect on the maximum extrusion pressure was determined by each experiment of extrusion. At elevated temperatures, it was little affected by the strain, but greatly depended upon the strain rate, on the contrary to the case in cold extrusion.
The strain rate varied according to the point of billet and it was important to know how to determine the average strain rate. This method was established by analysis of the experimental results for calculating the maximum extrusion pressure.
In hot extrusion, the yield strength usually decreased owing to the temperature rise caused by the heat which had been generated during extrusion by the conversion of a part of extrusion energy.
It should be also noted that the yield strength increased by the work hardening during extrusion.
As the results of the above studies, the empirical formula was derived to calculate the maximum extrusion pressure.抄録全体を表示PDF形式でダウンロード (1336K) -
三谷 裕康, 永井 宏1971 年 21 巻 10 号 p. 639-647
発行日: 1971/10/30
公開日: 2008/07/23
ジャーナル フリーThis paper describes the bubbling of AlCl3 gas in molten aluminum for the purpose of obtaining a more reliable value of the equilibrium constant of subhalide reaction and for clarifying the effects of alloying elements on this reaction.
By reducing the hole diameter of bubbling tube from 5 to 1mmφ, the reaction arrived in equilibrium state and the equilibrium constant was directly determined in the temperature range of 1, 0001, 200°C. The relation between the equilibrium constant and the standard free energy was expressed by the following equations:
logKp=-16.7×103/T+11.4
ΔG°T=76, 200-52.2T
The reactivity of AlCl3 with Al-Si or Al-Fe binary alloys was also investigated by the bubbling method. In consideration of the results of these experiments and the equilibrium constant, the activities of aluminum in these alloys were determined at 1, 200°C. The activity curves determined in these experiments were in good agreement with those previously obtained by other authors.
The contents of Fe and Si in Al derived from Al-Fe or Al-Si binary alloys were determined by emission spectroanalysis. The results showed that the Fe content was little, but the Si content was always constant at 0.25% independent of the presence of Si in the original material. The introduction of Si and Fe to the product was discussed by thermodynamic calculations on the experimental data. It was made clear that the introduction resulted from the reaction between the oxide of Si or Fe and AlCl or AlCl3.抄録全体を表示PDF形式でダウンロード (1046K) -
三谷 裕康, 永井 宏1971 年 21 巻 10 号 p. 648-652
発行日: 1971/10/30
公開日: 2008/07/23
ジャーナル フリーThis paper describes the determination of Al activities in molten ternary Al-Si-Fe system alloys by e. m. f. measurements of the following reversible concentration cell in the range of 7501, 100°C for selecting raw material compositions suitable for the subhalide process:
Al_??_Al+++(KCl+NaCl)_??_Al-Si-Fe(1 or 1+s)
Judging from the activities of Al obtained and the reactivity between AlCl3 and Al-Si-Fe alloys, containing various amounts of Si and Fe, measured by the bubbling method, it was concluded that the liquid Al-Si-Fe composition of Fe/Si = 1.52.0 was the most suitable raw material in this process.
On the basis of the values of Al activities, the activities of Si and Fe in Al-Si-Fe ternary system were calculated by Schumann's method at 1, 000°C.抄録全体を表示PDF形式でダウンロード (622K) -
佐藤 四郎1971 年 21 巻 10 号 p. 653-660
発行日: 1971/10/30
公開日: 2008/07/23
ジャーナル フリーThe effects of the change in specimen dimension on the elongation percentage were investigated for various aluminum alloy sheets, of which the specimens had various widths and a constant length of the reduced section.
As the results of tests, it was found to be desirable that the length of the reduced specimens would be determined by the following equation, independent of the kind of aluminum alloys:
Lc ≥ L0+0.8W
Lc: length of reduced section
L0: gauge length
W: width of reduced section
On the other hand, it has already been found that when the ratio of gauge length to the square root of cross-section area (L0/√A) is kept constant, the percentage elongation is reasonably constant, independent of the change in shape of the cross-section. Therefore, it was desirable that the test specimens having constant values of L0/√A would be used for the tension tests. However, sheet-type test pieces should be usually used in full plate thickness and the size of specimens for the above tension tests was difficult to be selected.
Then, a percentage elongation (δ) was obtained from a specimen having an arbitrary value of L0/√A, and the value corresponding to L0/√A=10 could be converted from the above value measured by Oliver's Equation.
The "converted elongation percentage (δ0)" can be used as a ductility index of material itself for discussing elongation percentages of different sheet metals and the same metal under different conditions. The conversion from δ into δ0 can be determined very simply by using the alignment chart.抄録全体を表示PDF形式でダウンロード (852K) -
溶接凝固に関する基礎的研究(第4報)福井 利安, 難波 圭三1971 年 21 巻 10 号 p. 661-669
発行日: 1971/10/30
公開日: 2008/07/23
ジャーナル フリーThis paper discusses the morphology of solute bands (or layer lines) observed in MIG or TIG welds of a commercially pure aluminum and Al-Mg, Al-Zn-Mg and Al-Mg-Si alloys, and their effects on several properties of welds.
The solute bands were noted as macrostructures having light etched lines or bands or as microstructures corresponding to the region of coarse dendrite cells in 99.5%Al and -4.5%Mg alloy welds; or as microstructures corresponding to the grain-refined region in Al-4%Zn-2%Mg alloy welds containing some grain-refined elements. They were observed to be formed penetrating the grains in cycles perpendicularly to the direction of solidification or heat flow, independent of the presence of feathery grains.
The effects of solute bands on the properties of welds were confirmed by the variation of hardness or indirectly by the marks on fractures of impact test specimens. Some of the effects were also observed by the distribution of porosity in parallel bands and the cyclic propagation of weld cracks corresponding to the solute bands.
The formation of solute bands depended upon the welding speed and heat inputs. They had comparatively similar characteristics to those of the wavy surface ripples on the weld bead surface, but seemed not to be identified with the ripples because of the differences in number and region of their occurrence.
The formation of solute bands was considered to be directly related to the periodic fluctuations in growth rate of weld solidification interface, resulting from the effects inherent in weld solidification such as the release of the latent heat of fusion on the liquid-solid interface. Moreover, these fluctuations seemed to be affected also by the external factors associated with the welding process.抄録全体を表示PDF形式でダウンロード (3592K) -
塩田 亘1971 年 21 巻 10 号 p. 670-683
発行日: 1971/10/30
公開日: 2008/07/23
ジャーナル フリーPDF形式でダウンロード (1764K)
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