巻号一覧
40 巻, 11 号
選択された号の論文の12件中1～12を表示しています
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小林 勝, 李 明哲, 佐久田 博司1990 年 40 巻 11 号 p. 805-810
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーIn order to estimate the mechanical properties and microstructures in forging processes, basic experiments were carried out for obtaining the fundamental data of hardness distribution and grain size, and the relationship between results and working conditions was formulated. The hardness distribution and microstructures in forged specimens were simulated by the method of elastoplastic FEM analysis. The hardness distribution and grain size predicted by the simulation almost agreed with the experimental results, and the validity of that method for predicting mechanical properties and microstructures was verified. The hardness and grain size of worked specimens in the deformation obviously depended on the equivalent plastic strain, and hardly depended on the forming method.抄録全体を表示PDF形式でダウンロード (1715K) -
能登谷 久公, 山田 茂, 吉川 和男, 高辻 雄三, 沖野 捷男1990 年 40 巻 11 号 p. 811-816
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーSintered WC tools are known to be effective and economical cutting tool for titanium alloy. Carbide tools with various grain size, content of WC and side rake angle were tested to evaluate the cutting performance-tool wear, cutting force and finished surface-in machining of commercial pure titanium. The wear resistance of the tools changes with the grain size of WC, in such a way that the tool with 1μm WC grain is the best. The wear of the tool with 94wt% WC is the smallest among the composition range of WC between 93 and 97wt% under the grain diameter of WC fixed to about 1μm. The tool wear progresses slowly and the level of cutting force is low for the tools with pressed chip breaker, regardless of WC content. An excellent cutting performance is found to be obtainable with the tool which has a side rake angle between -π/39 and π/36 rad.抄録全体を表示PDF形式でダウンロード (783K) -
大野 篤美, 本保 元次郎, 河合 秀信1990 年 40 巻 11 号 p. 817-821
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーAl-4.5 mass% Mg alloy billets were cast by the heated mold continuous casting (Ohno Continuous Casting) method developed by the authors. The billets were cold worked by 90° bending and cyclic bending. The relationships between the bending workability, crack initiation, mechanical properties and structures of the billets were examined and compared with those of billets produced by the conventional method. The specimens bent from conventional billets tend to exhibit crack initiation at the grain boundary and fracture easily, but the specimens from the OCC billets were free from such defects. The bending fatigue life of the OCC billets was five times that of the conventional billets, and the OCC billets moved through the cyclic bender easily but the conventional billets did not. Mechanical properties of the OCC billets such as hardness, tensile strength, elongation and fatigue strength were superior to those of the conventional billets. Mechanical properties of the OCC billets were improved by cyclic bending.抄録全体を表示PDF形式でダウンロード (1029K) -
佐藤 忠夫, 古川 純, 嶋影 和宜1990 年 40 巻 11 号 p. 822-827
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーIn the current investigation, continuous SiC fibers/aluminum alloy composites using AA6061 alloy plates and preformed wires which consist of continuous SiC fibers and AA1050 aluminum have been prepared by a vacuum hot press method, and wear properties of these composites have been examined against S45C steel wheel under lubricant conditions. FRM prepared was the unidirection reinforced composites involving continuous SiC fiber of 4.3 vol%. Three kinds of composite surfaces classified by the reinforced direction of SiC fibers and two kinds of matrix surfaces distinguished by the cutting direction of the stacking alloy plates were used for a wear testing. The experimental results obtained are summarized as follows: (1) Wear loss of continuous SiC fibers/aluminum alloy composites is much smaller than that of the matrix alloy, and the SiC fiber in composites is found to improve wear resistance. (2) The reinforced direction of SiC fibers for wear resistance is more effective in the order of longitudinal>perpendicular>transverse. (3) The difference in the kinetic frictional coefficients is not recognized between the composite surface and the matrix one.抄録全体を表示PDF形式でダウンロード (1242K) -
工藤 健, 武石 洋征, 峯岸 知弘1990 年 40 巻 11 号 p. 828-832
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーPure Mg plate cast by heated mold continuous casting method (O.C.C-Mg) have layer structure of the columnar crystals parallel to the casting direction. The acoustic proparties of O.C.C.-Mg is compared with that of pure Mg cast by conventional casting method (polycrystal Mg). One dimensional stress wave which formed the single pulse (stress pulse) was used for investigation of their properties. The stress wave was generated by a gas-gun and the stress wave was detected by strain gages. The amplitude and duration time of the stress wave dependence of the attenuation constants obtained from both peak value and energy of the strain are confirmed. Moreover, attenuation characteristics of the specimen after annealing is compared with that of specimen as cast to confirm the influence of the change in grain structure of O.C.C.-Mg and polycrystal-Mg by annealing on the attenuation characteristics. In addition, frequency distribution which is connected to attenuation of stress wave in O.C.C. or polycrystal Mg is studied by Fourier analysis.抄録全体を表示PDF形式でダウンロード (913K) -
沖 善成, 吉田 善博, 山下 友一1990 年 40 巻 11 号 p. 833-838
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーIn the mathematical model developed, the mechanical energy for extrusion translated into the terms of heat produced during deformation as well as increasing in temperature, and changes in the deformation-resistance and frictional-resistance were calculated. The change of extrusion speed could be attained on the assumption that the maximum extrusion pressure was maintained until the preset extrusion speed was reached. The characteristics of die can be estimated at the stage of die design. By the improved die design using this model, the extrusions of larger and more complicated shapes can be produced.抄録全体を表示PDF形式でダウンロード (750K) -
大崎 修平, 高橋 恒夫1990 年 40 巻 11 号 p. 839-844
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーConstant immersion corrosion test and electrochemical measurement in NaCl solution were carried out to clarify localized corroison behavior in a thick plate of 7475 alloy comparing with 7075 alloy. The effect of aging treatments on the formation of localized corrosion fissure was investigated metallurgically and electrochemically. The T6 tempered alloy showed a high susceptibility to localized corrosion, and the extension law in the direction of fissure depth was estimated as a function of immersion time. Two pitting potentials were found out on the anodic polarization curve of 7475-T6, and the less noble potential was corresponding to the onset of localized corrosion. The preferential dissolution path was shown to agree with the region involving both the grain boundary and outside area of cored structure resulted from microsegregation of Cr or Ti. The presence of Fe-bearing second phase particles played a part to facilitate the formation of localized corrosion fissure.抄録全体を表示PDF形式でダウンロード (1254K) -
山森 哲夫, 鏡味 文雄, 酒井 義文1990 年 40 巻 11 号 p. 845-849
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーAluminum composites reinforced with beta type silicon carbide whisker were prepared by hot pressing in vacuum. The whiskers with different avarage length were dispersed and separated in an isopropyl alcohol-water mixture. To evaluate the strength of those composites, Kelly-Tyson's equation was tried to be modified. The modification was performed by introducing a strengthening factor consist of factors caused by (1) inclination of fiber, (2) bending of crossing fiber, (3) stress-concentrating of fiber end, (4) interface between matrix and fiber. The strength of composites could be estimated by that modified equation. The strengthening factor was 0.12. A critical fiber length of whisker was 11μm and did not depend upon the fiber volume fraction but upon the strengthening factor.抄録全体を表示PDF形式でダウンロード (815K) -
新宮 秀夫1990 年 40 巻 11 号 p. 850-855
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーPDF形式でダウンロード (1128K) -
川島 敏彦1990 年 40 巻 11 号 p. 856-872
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーPDF形式でダウンロード (2283K) -
熊井 真次1990 年 40 巻 11 号 p. 873-875
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーPDF形式でダウンロード (340K) -
長 隆郎1990 年 40 巻 11 号 p. 876-877
発行日: 1990/11/30
公開日: 2008/10/30
ジャーナル フリーPDF形式でダウンロード (271K)
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