巻号一覧
61 巻, 7 号
選択された号の論文の8件中1～8を表示しています
- |<
- <
- 1
- >
- >|
研究論文
-
山田 浩之, 堀川 敬太郎, 松本 武史, 小林 秀敏, 小笠原 永久原稿種別: 研究論文
2011 年 61 巻 7 号 p. 297-302
発行日: 2011/07/30
公開日: 2011/08/30
ジャーナル フリーIn order to elucidate the hydrogen embrittlement of the aluminum alloys, it would be worthwhile to detect hydrogen evolution during tensile deformation and fracture. In this study, the hydrogen evolution behavior during tensile deformation and fracture in T6-tempered 6061 and 7075 aluminum alloys was detected by means of a testing machine equipped with a quadrupole mass spectrometer installed in an ultra-high vacuum chamber. Furthermore, local hydrogen evolution behavior of the both alloys was visualized with a hydrogen microprint technique. It is clarified that the hydrogen evolution started at the stage of elastic deformation in the both alloys. However, the amount of hydrogen evolved at the elastic deformation in 7075 alloys was much higher than that in 6061 alloys. This suggested that the hydrogen diffusion was promoted due to the existence of the stress field, since the 7075 alloy has higher proof stress than the 6061 alloy. In addition, the higher amount of hydrogen was evolved at the beginning of plastic deformation particularly in the 7075 alloy. This indicates that primarily dissolved hydrogen was transported to the surface of specimen with the aid of mobile dislocations. The amount of hydrogen evolved at the fracture in 7075 alloys was much higher than that in 6061 alloys.抄録全体を表示PDF形式でダウンロード (3712K) -
島村 亮, 杉本 明義, 藤原 賢彰, 世利 修美原稿種別: 研究論文
2011 年 61 巻 7 号 p. 303-309
発行日: 2011/07/30
公開日: 2011/08/30
ジャーナル フリーAttempt has been made to clarify anodic polarization behavior between theoretical procedures and experimental measurements. The theoretical procedures were derived from Nernst equation and the experimental measurements were carried out by use of potentiodynamic polarized technique: anodic curves of 1050 aluminum were obtained in solution containing chloride ions of 0.01, 0.1, and 1.0 mol · dm−3 as solute of sodium chloride and aluminum chloride. It was found that anodic polarization curves were influenced by their own oxide film. Pitting potential observed on anodic polarization curves were interpreted as cross point of superimposition of anodic reactions of Al/Al(OH)3 and Al/AlCl3. Theoretical meaning of pitting potential was explained as half potential of anodic half reaction of Al/AlCl3.抄録全体を表示PDF形式でダウンロード (939K) -
小橋 眞, 山田 裕磨, 金武 直幸原稿種別: 研究論文
2011 年 61 巻 7 号 p. 310-315
発行日: 2011/07/30
公開日: 2011/08/30
ジャーナル フリーMagnesium matrix composites were fabricated with the help of a reaction between magnesium and silicon oxide (SiO2) powders. The specimens were prepared by two processing routes (a powder processing route and an infiltration route). The basic reaction behavior was investigated by heating compacted SiO2 and magnesium powder blends. The effects of aluminum oxide (Al2O3) powder addition on the microstructures were investigated by the infiltration route. Magnesium oxide (MgO) and magnesium silicide (Mg2Si) were synthesized by the reaction between magnesium and SiO2. By the powder processing route, an explosive reaction took place when the volume blending ratios of SiO2/Mg were in between 20/80 and 30/70, and the specimens were highly porous. This explosive reaction became remarkable by decreasing the SiO2 powder size. The thermodynamic calculation revealed that the adiabatic temperature (Tad) of the specimen exceeded the boiling point of magnesium when SiO2/Mg were in between 20/80 and 30/70. Molten magnesium infiltrated into the SiO2 powder phase spontaneously under the heating condition of 800°C for 3.6 ks. The microstructure after the infiltration consisted of MgO, Mg2Si and magnesium. The course MgO agglomerates, which might be formed by the high temperature at aninfiltration front, were observed in the microstructure after the infiltration. By blending an Al2O3 powder (30 vol%, 50 vol%) in the SiO2 powder, the MgO phase became finer to several microns. The pores were hardly visible in the microstructure of the specimens fabricated by the infiltration route. The micro-Vickers hardness data showed that the hardness of the specimen was improved by blending the Al2O3 powder.抄録全体を表示PDF形式でダウンロード (3780K) -
小椋 智, 廣澤 渉一, 廣瀬 明夫, 里 達雄原稿種別: 研究論文
2011 年 61 巻 7 号 p. 316-321
発行日: 2011/07/30
公開日: 2011/08/30
ジャーナル フリーThe additions of microalloying tin and (silver and tin)-combination were performed to modify the precipitate microstructure in the vicinity of grain boundaries with precipitate free zones (PFZs) and mechanical properties in Al–Zn–Mg alloys. In the Sn-containing alloy, TEM observation showed that some precipitates were sparsely formed within the region of PFZs of the Al–Zn–Mg ternary alloy. The quantitative analysis of the chemical compositions in precipitates showed that tin mainly contributes to nucleation in the vicinity of grain boundaries through the suppression of the vacancy depletion. This is well explained by the favorable interaction of tin with vacancies. The (Ag+Sn)-containing alloy formed a very narrow PFZ width and corresponding tensile properties were remarkably improved, which shows that tin enables to reduce the amount of microalloyed silver in Al–Zn–Mg alloys.抄録全体を表示PDF形式でダウンロード (3854K) -
西田 太一, 小椋 智, 藤本 光生, 廣瀬 明夫原稿種別: 研究論文
2011 年 61 巻 7 号 p. 322-327
発行日: 2011/07/30
公開日: 2011/08/30
ジャーナル フリーFriction stud welding with zinc insert was applied to 5000 series aluminum alloys. A cone-shaped A5056 stud bolt was successfully friction-welded onto A5083 plate at low torque using zinc insert compared to that without zinc insert. This is considered to be contributed by a eutectic reaction between aluminum and zinc, which can effectively remove the oxide film and promote the joining. With bigger torque and longer welding time, the amount of residual zinc was reduced and high strength was achieved. On the other hand, a twist break between the stirred zone and the stud bolt increased during friction and this causes the decrease of tensile strength of the joint after a certain amount of torque. The results of micro-tensile test showed that strength at the edge of joint interface was higher than that at the center area regardless of zinc insert. From the experimental results, the joining process of the present friction stud welding classified into five processes, i.e. wear of stud bolt, start of joining, increase of tensile strength, decrease of tensile strength, and fracture during friction.抄録全体を表示PDF形式でダウンロード (5214K) -
柿崎 正悟, 渡邉 満洋, 熊井 真次原稿種別: 研究論文
2011 年 61 巻 7 号 p. 328-333
発行日: 2011/07/30
公開日: 2011/08/30
ジャーナル フリーMetal jet emission and weld interface formation in impact welding were investigated for similar- and dissimilar-metal lap joints. Numerical simulation of oblique collision between metal plates was performed using smoothed particle hydrodynamics (SPH) method for various plate thicknesses, collision velocities, and collision angles. Metal jet emission and formation of the characteristic wavy weld interface in impact welding were reproduced successfully. The composition of the metal jet was governed by the degree of relative density difference between two metals. When the density difference was large, such as Al/Cu and Al/Ni lap joints, the metal jet was mainly composed of the metal component with lower density, Al. On the other hand, when the density difference was small or zero, such as for Cu/Ni and Al/Al lap joints, the metal jet was composed of both metal components. Several types of lap joints were fabricated by magnetic pulse welding (MPW). Metal jets emitted from Al/Cu and Cu/Al lap joints were collected, and their components were analyzed by X-ray diffraction. The microstructure of the weld interface was also examined. The experimental results were in good agreement with the simulation results.抄録全体を表示PDF形式でダウンロード (7973K)
解説
-
植木 徹, 遠藤 至, 松下 彬, 吉田 誠原稿種別: 解説
2011 年 61 巻 7 号 p. 334-340
発行日: 2011/07/30
公開日: 2011/10/30
ジャーナル フリーPDF形式でダウンロード (2440K)
連載講座
-
廣澤 渉一2011 年 61 巻 7 号 p. 341-354
発行日: 2011/07/30
公開日: 2023/01/30
ジャーナル フリーPDF形式でダウンロード (7790K)
- |<
- <
- 1
- >
- >|