巻号一覧
40 巻, 1 号
選択された号の論文の11件中1～11を表示しています
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大柏 英雄1990 年 40 巻 1 号 p. 1-2
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーPDF形式でダウンロード (311K) -
Taichi SATO1990 年 40 巻 1 号 p. 3-6
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーThe thermal transformation of aluminum hydroxide, nordstrandite, prepared by the ageing of amorphous aluminum hydroxide in aqueous solution of ethylenediamine, has been investigated by thermogravimetry, differential thermal analysis, X-ray diffraction study and infrared spectrophotometry. As a result, it is found that the thermal transformation of nordstrandite proceeds in the following sequence:
nordstrandite→η-alumina→θ-alumina→α-alumina.
This process is similar to that of bayerite-II.抄録全体を表示PDF形式でダウンロード (369K) -
恒川 好樹, 奥宮 正洋, 新美 格, 前田 隆弘1990 年 40 巻 1 号 p. 7-12
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーCylindrical aluminum alloy matrix composites (MMC) containing alumina fibers were fabricated by applying a centrifugal force to fibrous preforms at room temperature before infiltration. Fiber segregation towards the outer periphery disappeared after infiltration, since boiling of carbon-tetrachloride as a mixture with the fibers relieved fiber segregation at the drying stage between the centrifuge and infiltration processes. However, the fibers tended to be aligned with a tangential direction of cylindrial fibrous preform by a centrifugal force. The MMC with high fiber volume fraction (Vf) showed only a poor alignment of fiber due to the dense fiber packing, while the one with low-Vf also showed a poor alignment due to long fiber length. Consequently, the MMC with Vf of nearly 20% showed the highest strengthening efficiency in bending tests. The bending strength increased with increasing Vf, and showed about a 200MPa rise compared to those of the MMC with the planar-randomly oriented fibers and the same Vf.抄録全体を表示PDF形式でダウンロード (935K) -
神尾 彰彦, 手塚 裕康, 村上 雄, 吉永 直樹, 桜井 喜宣1990 年 40 巻 1 号 p. 13-19
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーMicrostructures and hardness of rapidly solidified Al-8 mass%Fe and Zr-contained alloys prepared by a single roller technique have been investigated. The structure of the Al-8 mass%Fe alloy ribbon has two different types of structures in morphology. One is called zone A and is composed of dendritically-grown α-Al and fine metastable phases. The other is called zone B and contains three phases: cellular α-Al and fine metastable phases and Al6Fe phase. During heat treatment at 400°C, these fine phase and Al6Fe phase transform to a stable phase Al3Fe with coarsening and the hardness of the Al-8 mass%Fe alloy decreases due to this structural change. The addition of Zr retards these transformation by Zr supersaturation and hardens the matrix by Al3Zr precipitation. These phenomena become more pronounced with increase in the amount of Zr, maintaining the alloy strength even after the exposure at high temperatures.抄録全体を表示PDF形式でダウンロード (1324K) -
古川 稔, 王 海波, 根本 実1990 年 40 巻 1 号 p. 20-26
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーThe deformation induced dislocation structures in the chill cast and aged Al-Zr alloys were examined by transmission electron microscopy at various stages of aging. The Al-Zr alloys hardened by precipitation of the metastable β'-Al3Zr phase with the L12 ordered structure. In contrast to the Al-Li alloys containing coherent δ'-Al3Li particles which have the same L12 ordered structure as the β' phase, dislocations moved as single dislocations and bypassed the β' particles at any aging stage of the Al-Zr alloy. This behavior of dislocations in the Al-Zr alloy was explained in terms of the large value of antiphase boundary energy and the small volume fraction of the β' precipitates.抄録全体を表示PDF形式でダウンロード (4003K) -
王 海波, 古川 稔, 根本 実1990 年 40 巻 1 号 p. 27-35
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーThe effects of addition of Li on the precipitation of β'-Al3Zr phase in the chill-cast Al-Zr alloy were studied by means of transmission electron microscopy. The optimum dispersion of β'-Al3Zr and δ'-Al3Li precipitates in the Al-Li-Zr alloys was attained by controlling Li content, solution treatment and aging temperatures. In the Al-0.3 mass% Zr-2.3 mass% Li alloy, the β' phase progressively precipitated during aging at 673K without precipitation of δ' phase. The addition of Li to the Al-Zr alloy accelerated the initial stage of aging at 673K and suppressed the over-aging of the alloy. The first stage aging at 673K for 1.08×106s provided an increase in the yield stress of 120MPa. The peak yield stress of the alloy successively aged at 473K was about 280MPa, which was higher than that of Al-3 mass% Li binary alloy. The split aging was effective for age hardening and suppression of over-age softening in Al-Li-Zr alloy.抄録全体を表示PDF形式でダウンロード (4245K) -
伊藤 吾朗, コテロ ブルノ, 菅野 幹宏1990 年 40 巻 1 号 p. 36-44
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーThe precipitate structure of the intermediate phase β', as well as the secondary defect structure, in an Al-8%Mg alloy was observed to clarify the nucleation process. Peculiar cares were allocated to reveal the effect of gas impurities by changing the casting procedure and the solution treatment atmosphere and by using the TEM tritium autoradiography technique. When the cooling rate during solidification was high enough, i. e. absence of porosity, regular-tetrahedronshaped voids were newly observed as secondary defects. Some of these voids happened to be nucleation sites for β' and thus the precipitate density was relatively high. On the contrary when the cooling rate was slow, voids were replaced by dislocation loops which played no role with respect to the nucleation process. Furthermore, a solution treatment under water vapor stream resulted in a substantial increase in precipitate density owing to the enhancement of the efficiency of voids as nucleation sites. Consequently, void formation was thought to be promoted by hydrogen which was dissolved into the matrix during solidification and then retained inside voids. The relationship between β' precipitation and hydrogen through void formation was confirmed by tritium autoradiography.抄録全体を表示PDF形式でダウンロード (2823K) -
井上 哲雄, 沖 猛雄1990 年 40 巻 1 号 p. 45-50
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーThe effect of grain size on polarization behavior of Al-Zn-Mg alloys has been investigated. The grain size has a good negative correlation with grain boudary length, i. e., the finer the grain size, the longer the grain boundary length. Pitting potential in 0.5N NaCl solution becomes noble and passivation current density decreases with increase in grain size. Passivation current density has a good negative correlation with pitting potential.抄録全体を表示PDF形式でダウンロード (740K) -
世利 修美, 田頭 孝介1990 年 40 巻 1 号 p. 51-55
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーA numerical parameter fpit which we call "pitting factor" has been introduced as a guideline for developing anti-pitting aluminum alloys. Availability of the factor is verified in a series of electrochemical measurements; a pitting attack will occur only when fpit is equal to or greater than unity.抄録全体を表示PDF形式でダウンロード (512K) -
森永 正彦, 斎藤 淳一, 湯川 夏夫, 足立 裕彦, 那須 三郎1990 年 40 巻 1 号 p. 56-63
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーPDF形式でダウンロード (983K) -
岡庭 茂1990 年 40 巻 1 号 p. 64-73
発行日: 1990/01/30
公開日: 2008/10/30
ジャーナル フリーPDF形式でダウンロード (1235K)
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