巻号一覧
56 巻, 5 号
選択された号の論文の8件中1～8を表示しています
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研究論文
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木下 勝之, 大崎 修平2006 年 56 巻 5 号 p. 249-254
発行日: 2006年
公開日: 2006/07/15
ジャーナル フリーEffects of specimen size and shape, grain size and aging condition on static tensile properties of Si-rich 6000 aluminum alloy sheets were investigated. The static tensile tests were carried out by using specimens both under-aged and peak-aged having six kinds of different size including standardized one of JIS 13B, two (coarse and fine) grain sizes. With the decrease in specimen size, yield strength decreased, while elongation increased. This response was remarkable in the case of the alloy with coarse grain size. From the SEM observation on fracture surface, the change in the elongation with decreasing specimen size was attributed to the shift of fracture mode from integranular to transgranular. The dependence of specimen size and shape was able to be explained with a parameter of the ratio of specimen width to grain size.抄録全体を表示PDF形式でダウンロード (1153K) -
小松 伸也, 阿部 晴彦, 櫻井 健夫, 池田 勝彦2006 年 56 巻 5 号 p. 255-260
発行日: 2006年
公開日: 2006/07/15
ジャーナル フリーWriting resistivity ratio ρ300/ρ77 as R and according to a linear relation between resistivity at 77 K, ρ77, and 1/(R−1) deduced from the Matthiessen's rule, the measured values of ρD77 using density method size factor have been plotted versus 1/(R−1). This diagram called as Matthiessen plot (MP) was very useful to detect errors in ρ measurements. Straight lines obtained by regression of the MP as ρD77=α/(R−1)+β were called as Matthiessen empirical relations (MER) . Other than the gradient α of the MER, a gradient α*=ρ77(R−1) of straight lines binding each plots and origin of the MP was induced. Using ρD77 and R data formerly measured in Al–1.0%Mg2Si– (0~0.7%) Cu alloys, variations in the two gradients with isothermal aging temperature and Cu addition were investigated. At all aging temperatures, the α was lower than the ideal value, 25.13 nΩ m for Al base solid solution without deviation from Matthiessen's Rule (DMR). The α decreased with lowering aging temperature from 473 K to room temperature and amount of Cu. A good linear relation was observed between α and β changed by aging temperature and Cu addition. The α* calculated from concentration of solutes in solution- treated and quenched state was decreased with the addition of Cu having negative DMR. The α* was increased by agings at and above 448 K, whereas decreased by room temperature aging. The α* increase by high temperature aging can be explained by overestimation of size factor due to high- resistivity precipitates decreasing the effective cross section for electric current. Assuming a large negative DMR of clusters or G.P. zones, the decrease in α* with room temperature aging can be understood.抄録全体を表示PDF形式でダウンロード (551K) -
吉原 伸二, 大崎 修平, 高井 弘治2006 年 56 巻 5 号 p. 261-265
発行日: 2006年
公開日: 2006/07/15
ジャーナル フリーEffect of Si particles on chipping characteristics of 6061 based aluminum alloys under two-dimensional cutting operations has been investigated. The formation of fine chips was promoted by adding above 2 mass% Si to the 6061 alloy. Induced shear strain on shear plane decreased with the increase in Si contents, while radius of curled chip reduced, leading to an increase in normal strain by bending. Si particles in the alloys reduced coefficient of friction between chip and rake surface of tool. It was therefore supported that the increase in normal strain by bending resulted from a reduction of radius of chips led to an easy fracture of chips.抄録全体を表示PDF形式でダウンロード (958K) -
江崎 宏樹, 渡辺 良夫, 上田 薫, 宇都 秀之, 渋江 和久2006 年 56 巻 5 号 p. 266-270
発行日: 2006年
公開日: 2006/07/15
ジャーナル フリーThe recycling of the aluminum alloy automotive body sheet containing the steel parts in the End-of-Life Vehicles (ELV) is a serious problem to be solved. This paper presents the results of the AA6016 alloy strips (6.0 mm thick and 300 mm wide), containing 0.4% iron experimentally produced by the twin-roll casting (TRC) method. Since a feature of this process is the effect of rapid solidification relative to conventional direct chill (DC) casting, the refinement of the intermetallic compounds containing iron is expected. The surface stripes called ripple marks on the TRC strips influence the surface quality of the final cold rolled sheet. For example, the ripple marks are detrimental to filiform corrosion resistance. Therefore, the optimum casting conditions such as casting speed and setback are clarified to suppress a ripple mark.抄録全体を表示PDF形式でダウンロード (2186K) -
吉原 伸二, 星井 博行, 木下 勝之, 大崎 修平2006 年 56 巻 5 号 p. 271-276
発行日: 2006年
公開日: 2006/07/15
ジャーナル フリーIn order to evaluate fracture toughness property of 6061-T6 aluminum alloys including Si particles, fracture toughness tests under mode I, mode II and mixed-mode I–II loadings were carried out for extruded alloy plates with various Si contents to 6 mass%, and the fracture process was studied by metallographic observations together with FEM stress analysis. Under tensile tests, Si-particles with a relatively rough size of 3–4 μm was found to crack themselves or exfoliate at interfaces with matrix, taking a role of preferential void formation sites, and to lead a reduction in ductility. Mode I fracture toughness JIa rapidly decreased with an increase in additional Si contents, where JIa of alloy #4 with 6 mass% Si fell to 11.5 kN/m, about a quarter of that of the base 6061 alloy #1 with 0.7 mass%Si. Mode II fracture toughness JIIa was substantially higher than JIa, showing a mild reduction with Si addition. These results could support mechanism of fine chip formation was dominated by mode I fracture. Mode I fracture of alloy #4 was induced in the preferential damage zone of Si particles ahead of notch root, where the principal stress σ1 exceeded the true fracture stress σfa in tension. Mode II fracture of alloy #4 in the inclined direction θ=−40° ahead of notch root was also supported to take place based on the above criterion.抄録全体を表示PDF形式でダウンロード (2074K) -
行武 栄太郎, 金子 純一, 菅又 信, 久保田 正広2006 年 56 巻 5 号 p. 277-282
発行日: 2006年
公開日: 2006/07/15
ジャーナル フリーDent resistance of AZ31 magnesium alloy sheets was examined under static and dynamic conditions. Dent tests were carried out for AZ31-O and AZ31-H24 sheets by using circular blanks and dent depth was measured and compared with that of aluminum alloys (1100-O, 5052-O, 5052-H34), copper alloy (C2801-O) and cold-rolled steel (SPCE) sheets. The critical punch load for initiation of the dent formation was not detected for AZ31 sheets in the punch load-stroke curves of static dent tests whereas it was clearly observed in steel sheet. In static dent tests, magnesium sheet with the lowest elastic modulus showed the largest spring back and consequently the smallest dent depth at the constant punch stroke. AZ31 sheet also showed smallest dent depth at the constant punch load. In dynamic dent tests, AZ31 sheet showed the highest dent resistance under various impact conditions. It is concluded that AZ31 magnesium sheets are suitable for various light weight panels with their excellent dent resistance as well as low density.抄録全体を表示PDF形式でダウンロード (1609K)
解説
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高橋 和仁, 村田 眞2006 年 56 巻 5 号 p. 283-289
発行日: 2006年
公開日: 2006/08/30
ジャーナル フリーPDF形式でダウンロード (1213K)
連載講座
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山口 賢之2006 年 56 巻 5 号 p. 290-297
発行日: 2006/05/30
公開日: 2021/06/30
ジャーナル フリーPDF形式でダウンロード (1597K)
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