巻号一覧
59 巻, 4 号
選択された号の論文の9件中1～9を表示しています
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研究論文
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鈴 拓也, 福本 信次, 山本 厚之原稿種別: 研究論文
2009 年 59 巻 4 号 p. 169-173
発行日: 2009/04/30
公開日: 2009/05/30
ジャーナル フリーGrain refinement, randomization of texture and improvement of mechanical properties on AZ31B magnesium alloy were attempted by applying the wavy form rolling method. Specimens were heated at 523 K and then wavy form rolling, followed by reheating at the same temperature and rolled again. The wavy rolls were heated at 423 K by attached roll heaters. Cracking did not occur during wavy form rolling. This process was repeated 8 times, then the specimen was flattened using conventional flat rolls at room temperature and finally annealed at various conditions. Grain sizes in the specimens were determined by optical microscope. Textures formed in the specimens were analyzed by electron backscattered diffraction measurements. Mechanical properties in the specimens were evaluated by tensile tests. The wavy form rolling and decreasing rolling temperature were useful for randomization of texture. But annealing after wavy form rolling at higher temperature and for longer time caused the basal plane texture. Anisotropy in mechanical properties of the wavy form rolling specimens was decreased in comparison with those in the starting materials.抄録全体を表示PDF形式でダウンロード (7896K) -
世利 修美, 戸島 拓也, 新井田 要一原稿種別: 研究論文
2009 年 59 巻 4 号 p. 174-178
発行日: 2009/04/30
公開日: 2009/05/30
ジャーナル フリーAttempt has been made to clarify an effect of iron element on cathodic behavior of aluminum in a substitute sea water. It is quantitatively shown that iron in aluminum shifts the cathodic polarization curve, which is the water reduction reaction, to noble direction. The values of exchange current density of water reduction reaction on FeAl3 intermetallic compound and 99.999%Al for the Tafel equation are experimentally estimated to 10−3.5 A·cm−2 and 10−7.0 A·cm−2, respectivery.抄録全体を表示PDF形式でダウンロード (1569K) -
酒井 孝, 吉田 慶介, 小山 純一, 仲町 英治原稿種別: 研究論文
2009 年 59 巻 4 号 p. 179-184
発行日: 2009/04/30
公開日: 2009/05/30
ジャーナル フリーA bending tester with an incorporated high-precision angle sensor was developed in this study. Pure aluminum single crystal and polycrystalline materials were used. Bending properties, especially the springback characteristics of materials as-received and fine-grained using AR and ECAP processes, were investigated. The springback characteristics are discussed based on various mechanical properties that were elucidated by tensile and hardness tests. Consequently, the following results were obtained. (1) AR and ECAP cold-processing refined grains of both single crystal and polycrystalline materials with almost no work hardening exhibited increased Vicker's hardness Hv without a decrease in elongation δ, at an equivalent strain ε of not less than 1.0. (2) The ECAP sample, which underwent many cycles of high strain processing, i.e., being subjected to large equivalent strain ε, indicated a large springback angle δSB. It also turned out that springback angle increased with an increment of δSB=0.1° per cycle of ECAP processing. (3) Both nECAP-s [110] and nECAP-p samples demonstrated a constant springback angle δSB, irrespective of equivalent strain ε at a bending angle of not less than δ=95°. (4) Fine-grained materials show a bigger springback angle δSB than as-delivered materials. Nevertheless, AR and ECAP samples, processed with different strain loading mode, showed little difference in the trend of spring back angle δSB against bending angle δ. (5) Steel materials over a wide range tend to indicate springback angle δSB in direct relation to the n value. However, fine-grained pure aluminum material of this study turned out not to conform to this trend. The result of this series can constitute fundamental data that are useful toward the establishment of a plastic deformation processing method of fine-grained materials.抄録全体を表示PDF形式でダウンロード (1625K) -
畑中 伸夫, 飯塚 高志, 高倉 章雄原稿種別: 研究論文
2009 年 59 巻 4 号 p. 185-189
発行日: 2009/04/30
公開日: 2009/05/30
ジャーナル フリーIn the stretching process, it is important to prevent the sheet thickness from thinning locally at punch shoulder and to decrease the thickness as uniform as possible. Then, if the material around the die hole is poured into the hole, the height of the cup is expected to rise more. From that point of view, a combined process of punch stretching, reverse stretching and ironing has been proposed using rubber punch. However, in that process, it was difficult to thin the sheet thickness uniformly especially on the punch head mainly due to the existence of frictional force. In this study, a new combined process of hydraulic bulging, reverse bulging and ironing was devised, and the increase in the height of cup with wide flange was attempted. In the experiment, the sheet thickness around the second die hole was thinned effectively by the hydraulic bulging, and the material corresponding to the decrease of the thickness was enabled to pour into the die hole by the following reverse bulging. However, to make the process successful, it was necessary to use a counter punch with contour like arc, and to press a wrinkle into the die-hole by using an assist punch after the reverse bulging. After additional ironing, the thickness strain of the formed cup could be distributed on the punch head more uniformly than which is formed by the process proposed previously. As the result, a cup with wide flange having the diameter of 41.5 mm and the height of 33.0 mm could be obtained.抄録全体を表示PDF形式でダウンロード (1679K) -
甲藤 晴康, 鈴木 聡, 堀川 宏, 山脇 慧, 北岡 山治原稿種別: 研究論文
2009 年 59 巻 4 号 p. 190-194
発行日: 2009/04/30
公開日: 2009/05/30
ジャーナル フリーAs for the Al–Si hyper-eutectic alloys with phosphorous addition, the primary Si size is dependent on the holding temperature relative to the “Critical Temperature Line for Grain Refinement”, which was discovered by the authors. If the holding temperature falls under this line, the size will be coarsened. Cooling rate is also said to be influential to the size of primary Si crystal, however, it is unknown which stage of cooling rate is preferential. The difference between the liquidus temperature measured with phosphorous addition and the liquidus temperature measured without phosphorous addition,is not clearly understood still. To understand these problems shown above, the thermo-analysis measurements were performed during the cooling of hyper-eutectic Al–Si alloys with and without phosphorous addition, under various cooling rates, in relation with liquidus temperature, primary Si size, etc. The results obtained are as follows: The two liquidus temperature lines of hyper-eutectic Al–Si alloys were obtained according to the alloys with phosphorous and without phosphorous, the latter shows fairly low temperature but the former shows almost the same temperature line with equilibrium diagram. This means that we can use the equilibrium diagram of hyper-eutectic Al–Si alloy as a “Imaginary Practical Phase Diagram of Hyper-eutectic Al–Si Alloy with phosphorus addition”. As for the relation between cooling rate and primary crystal size, the cooling rate above the liquidus temperature seems to be more influential to the primary crystal size, compared to the cooling rate between the liquidus line and eutectic line which is not influenced by phosphorous.抄録全体を表示PDF形式でダウンロード (354K) -
土田 信, 横井 洋, 金武 直幸原稿種別: 研究論文
2009 年 59 巻 4 号 p. 195-200
発行日: 2009/04/30
公開日: 2009/05/30
ジャーナル フリーThe combined method of rolling and simple tension to obtain the strain hardening exponent n-value by Hollomon's equation in wide strain range has been compared with the simple tension method in commercial pure aluminum alloy sheets. The n-value by simple tension method is measured to be 0.32, 0.36 or 0.25 respectively in the three stages of growing strain. The third and last stage is the strain range of 0.06~0.23 that is just before the necking. In comparison, the n-value by combined method is obtained to be 0.24 in the wide strain range of 0.06~2.2 in which the rolling strain up to 90% of thickness reduction is changed to the equivalent strain and added to the tensile strain. This n-value is recognized to be almost equal to the value by simple tension method. The changes of crystal orientation due to the deformation are different in these two methods, however, the similar dislocation cell structures are observed when the nearly equal n-values are obtained. These results support the utility of combined method standing on the assumption of plastic uniformity of material to obtain the n-value for wide strain range and suggest that n-value depends rather on the dislocation structures than the crystal structures.抄録全体を表示PDF形式でダウンロード (2763K)
解説
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――生産の現状堀 茂徳, 山本 成人原稿種別: 解説
2009 年 59 巻 4 号 p. 201-203
発行日: 2009/04/30
公開日: 2009/07/30
ジャーナル フリーPDF形式でダウンロード (7116K) -
山口 裕原稿種別: 解説
2009 年 59 巻 4 号 p. 204-215
発行日: 2009/04/30
公開日: 2009/07/30
ジャーナル フリーPDF形式でダウンロード (9961K)
連載講座
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鎌土 重晴2009 年 59 巻 4 号 p. 216-224
発行日: 2009/04/30
公開日: 2021/06/15
ジャーナル フリーPDF形式でダウンロード (789K)
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