材料
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
56 巻 , 7 号
選択された号の論文の15件中1~15を表示しています
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論文
  • 鈴木 賢治, 和田 国彦, 松原 秀彰, 菖蒲 敬久, 川村 昌志, 田中 啓介
    2007 年 56 巻 7 号 p. 588-593
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    The Ni-based superalloy IN738LC was used as the substrate material, and CoNiCrAlY powder was pressureless plasma-sprayed on the substrate as the bond coating. Zirconia was coated as the top coating by the electron beam-physical vapor deposition (EB-PVD) method. In the EB-PVD process, the specimens were kept at 1223K and rotated with 5rpm, 10rpm and 20rpm. According to the microscopic observation and the result of the pole figures, the top coatings had a columnar structure, which was made by the piling up of (111) planes. The cross section of the column had a diamond shape, and its diagonal was parallel to the rotation axis. The residual stress on the surface of the top coatings was evaluated by the X-ray diffraction method. Each diffraction profile was separated into the 133 and the 331peak, and the residual stress was measured by the sin2ψ method. The measured residual stresses were –76.7MPa for 5rpm, –63.0MPa for 10rpm and –25.1MPa for 20rpm.
  • 町屋 修太郎, 田中 啓介, 秋庭 義明
    2007 年 56 巻 7 号 p. 594-601
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    The stress in a single crystal of nickel-base superalloy with 72% volume fraction of γ'-phase was measured by the X-ray method. The specimen whose surface normal was parallel to [001] direction was oscillated around φ-axis during recording of the X-ray diffraction pattern with a two-dimensional position sensitive proportional counter (PSPC). The stress was determined from the measured strain using the multiple regression method and the two-tilt method. The uniaxial stress was applied along [100] direction and the stresses were measured with the X-ray methods. The stress along [100] direction, σ11, measured with the X-ray method increased proportionally to the applied uniaxial stress, and the measured stress was about 5% smaller than the applied stress. The other stress components, σ22 and σ12, did not change with the applied stress. With respect to the machined surface, the residual stress was a compression of about 700MPa on the surface and abruptly decreased to zero at about 15μm beneath the surface. The increase in the full-width at half maximum was observed within the depth of about 15μm from the machined surface.
  • 坂井田 喜久, 田中 恒輔
    2007 年 56 巻 7 号 p. 602-608
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    X-ray elastic constants, EX and νX, were measured before and after quenching using three kinds of carbon steel, S45C, S48C and S55C, defined by the Japanese industrial standard. The microstructures, mechanical elastic constants and hardness of these materials were also measured. Change of X-ray elastic constants caused by quenching corresponded to the microstructure change due to martensitic transformation, and depended on the mechanical elastic constant change. Amount of change in X-ray Young's modulus after quenching was different by the used material. The ratio of X-ray to mechanical Young's modulus, EX/EM, after quenching lowered in comparison with that before quenching, regardless of carbon content. Finally, using the measured X-ray elastic constants before and after quenching, compressive residual stresses on the hardened layer of S48C gear induced by induction hardening were measured by X-ray stress measurement. As a result, X-ray Young's modulus, EX, and stress constant, K, of S48C after quenching showed about 22% and 18% lowering to that before quenching, respectively. And then, the maximum deviation of compressive residual stress was about 86MPa in comparison with the result ignored considerations of microstructure change. It is concluded that estimation of stress constant considering microstructure change by quenching are necessary when the residual stresses of quenched carbon steel are measured by X-ray stress measurement.
  • 末吉 一行, 秋田 貢一, 大谷 眞一, 鈴木 裕士, 今福 宗行, 岩田 圭司
    2007 年 56 巻 7 号 p. 609-614
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    Grain-oriented 3%Si steel has been widely used for transformer cores. The reduction of iron loss is the most important factor for the development of the material and can be achieved by segmentation of magnetic domain of the material. The segmentation of magnetic domain is occurred by introduction of the residual stress induced by a laser pulse irradiation on the material. In this study, the residual stress distributions near laser pulse spots on a grain-oriented 3%Si steel were measured using an X-ray stress measurement method for single crystal and the generation mechanism of the residual stress was discussed. Laser pulses with 100μm in diameter were irradiated on the surface of the material. Tensile residual stress was generated near the center of laser spot and it rapidly decreased with increasing distance from the center of spot. The in-plane residual stresses showed anisotropy, however the in-plane strains calculated from the residual stresses and anisotropic elastic properties were isotopic. The X-ray diffraction profiles near the laser spots were broadened and it showed that the plastic strain was induced by local thermal expansion due to laser irradiation.
  • 鈴木 大介, 八代 浩二, 清水 誠司, 杉田 良雄, 齊藤 基樹, 久保田 勝彦
    2007 年 56 巻 7 号 p. 615-621
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    To reduce distortion due to quenching for small diameter round bar of carbon steel, an induction hardening instrument with a super-high frequency generator of 2MHz was developed. Quenching for specimen (6mm in diameter) was examined under various conditions of voltage and specimen transfer speed. Quenched specimen was evaluated by measuring hardness distribution, residual stress and distortion. As a result, the condition of 230V∼20.6mm/s brought about the good result : the depth of hardened zone was 0.4mm and the hardness near the surface was 600HV. As for the well-quenched specimens, the maximum compressive residual stress in the longitudinal direction reached –400∼–600MPa at surface, and decreased slightly from surface to center. However, at hoop direction, compressive residual stress was close to 0MPa. This anisotropy was due to large thermal stress compared with the present induction hardening and conventional one. The specimen that had deeper hardened zone had large distortion equivalent full quenching, and the specimens that had thinner hardened zone had small distortion as same as annealing or non-heat-treatment specimens.
  • 田中 啓介, 岩田 吉史, 中川 時児, 秋庭 義明, 木村 英彦
    2007 年 56 巻 7 号 p. 622-628
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    Fatigue crack propagation tests of PZT ceramics were conducted by using 4 point bending of single edge-notched specimens under cyclic and static loading conditions. Domain switching (DS) in the vicinity of fatigue cracks in PZT ceramics was evaluated from the intensity ratio of 002 to 200 diffractions measured by X-ray microdiffraction. The change of the crack propagation rate with crack extension can be divided into three regions. In region I, the crack propagation rate decreases with increasing crack length, and then turn to increase in region III. In region II, the propagation rate is nearly constant. The crack propagation rate was higher in the order of cyclic fatigue with frequency of 30Hz, cyclic fatigue with 0.3Hz and static fatigue. DS near the crack tip was divided into two kinds : one is the residual DS left without load and the other was reversible during loading-unloading cycle. The amount of residual DS increased with crack extension. The decrease of crack propagation rate in region I was caused by the development of DS and interlocking between crack faces. In region III, the increase of the applied stress intensity factor became dominant, then accelerated crack propagation. Region II was the transitional region. The fatigue fracture surface made by static fatigue had the largest amount of residual DS and the largest fraction of intergranular fracture.
  • 柴野 純一, 小林 道明, 三浦 節男, 平田 智之, 西川 真弘
    2007 年 56 巻 7 号 p. 629-634
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    Residual stresses which occur in a thin plate and a film of both MEMS and an electric device have become a direct cause of a deformation and a destruction of them. To evaluate the residual stress is therefore very important for improving their mechanical reliability. A strain gauge is often incapable of using to measure the strain of the thin plate and the film, while X-ray diffraction method is effective in the nondestructive measurement of residual stress of them. If a diffracted X-ray transmitted through the thin plate is available, spacing of the lattice plane orthogonal to the direction along the surface could be measured directly. It suggests potentiality for the strain measurement of thin plate with high precision and efficiency. This paper presents a new measurement method of the stress in a polycrystalline thin plate by using transmission diffracted X-rays. This method is able to determine the principal stress and its direction in the thin plate from the measurement of the lattice spacing with random three directions within thin plate and the vertical direction of thin plate surface. The method was verified using a pure aluminum thin plate of 50μm thickness which was loaded with tension using compact tensile loading equipment. The X-ray elastic modulus of Al(311) lattice plane which was measured at the start of the experiment was derived as Young's modulus of 61.7GPa and Poisson's ratio of 0.33. As a result, principal stress and its direction in the aluminum thin plate could be evaluated with errors of less than about 9MPa and 3degree, respectively. It was confirmed that this method is effective for the stress measurement of thin plate.
  • 松英 達也, 英 崇夫, 池内 保一
    2007 年 56 巻 7 号 p. 635-640
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    The present study investigates crystal orientations and residual stresses in multi hard layer films deposited by arc ion plating. TiN and CrN films approximately 1.0μm thick in single layer were deposited on a stainless steel substrate. With a bias voltage of 0V, the TiN film exhibited strong {110} texture, whereas the dominant orientation of the film deposited at –100V was {111}. On the other hand, CrN films exhibited strong {110} texture with a bias voltage of –100V. The crystal structure of double-layer film had the same tendency as those for single-layer films. TiN films had very high compressive residual stresses : –8.6GPa in the {110} textured film and –10.0GPa in the {111} textured film. These residual stresses decreased with increasing annealing temperature and the reduction rate was greater for the {111} than for the {110} film. The behavior of residual stresses in the {111} and {110} textured layers of {111}/{110} textured double-layer film was identical to that for single-layer films. The CrN films had very high compressive residual stresses of –8.4GPa. These residual stresses decreased with increasing annealing temperature. However, Annealing of temperatures at 600°C showed change in peak intensities of CrN 220 diffraction.
  • 小栗 泰造, 村田 一夫, 山口 勝己
    2007 年 56 巻 7 号 p. 641-646
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    A new X-ray stress measuring technique – dual-axis inclining method – has been developed to measure stress on a flat surface at confined area like a side-wall of V-groove non-destructively. This technique allows one to measure two mutually orthogonal stress components of the side-wall – the normal stress in the groove-height direction σT and that in the groove-line direction σL – without eliminating a facing side-wall. This technique is characterized by the combination of the iso-inclination scanning (ψ angle) and the side-inclination scanning (Ω angle). The iso-inclination scanning in the plane including the groove-line leaving the side-wall inclined from the reference axis of goniometer's rotation, i.e. the ψ rotation under Ω ≠ 0deg, gives an apparent stress in the groove-line direction. Measuring the relation between the apparent stress and sin2Ω for available range on Ω in which the X-ray path is not prevented by the facing side-wall, one can obtain σL from the y-intercept by extrapolating the regression line of the relation to sin2Ω = 0 and σT from the gradient of the regression line. The validity of this technique was verified by applying this technique and the conventional method to a flat specimen respectively, and comparing the values measured.
論文
  • 陸 偉, 三村 耕司
    2007 年 56 巻 7 号 p. 647-653
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    In this study, we employ the two-dimensional homogenization model based on molecular chain network theory to investigate the micro- to macroscopic mechanical behavior of porous polymer under macroscopic uniform compression. A parametric study is performed to quantify the effect of a characteristic value of polymer matrix, the distribution and the initial volume fraction of voids, and the macroscopic triaxiality of loading condition on the deformation behavior of porous polymer. The results suggest that the initial elastic modulus and the macroscopic yield stress of porous polymer have no dependence on the characteristic value of polymer matrix. The onset of localized shear band at the ligament between voids leads to the macroscopic yield of porous polymer. Furthermore, the microscopic localized shear deformation behavior is promoted in case of high initial volume fraction of voids and high triaxiality loading condition, which results in the early appearance of the macroscopic yield. After the macroscopic yield, microsopic buckling onsets at the ligament between voids and a remarkable strain hardening occurs in case of high initial volume fraction of voids and high triaxiality loading condition due to the considerable increase of the density of porous polymer.
  • 林 為人, 高橋 学, 藤井 幸泰, 西山 哲, 竹村 貴人
    2007 年 56 巻 7 号 p. 654-659
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    In order to understand and model relations between microstructure of rocks and their physical properties, uniaxial tension tests were conducted on specimens of nine granitic rocks included a granite, four granodiorites and four tonalities, and two gabbros which were taken from eastern Japan. The axial and transversal deformability of these rocks was determined based on strain measurements using wire strain gauges. The experimental test results revealed that deformational properties of the rocks investigated varied depending on their petrographic features. However, the axial strain and the lateral strain characteristics showed a similar trend for all the rocks, i.e. the stress-strain curves were non-linear throughout the whole stress range from the initial point of loading to the point of ultimate failure. Moreover, the tangent Young's modulus and the ratio of the lateral strain to the axial strain decreased monotonously with the increasing of the axial stress. Still, the deformational properties were different for individual rocks in a quantitative sense. In particular, the difference in the lateral strains among different rocks was more distinct than that in the axial strains. For example, the Poisson's ratio at a stress level equal to 50% of the ultimate strength of a granodiorite was very low, close to zero. Furthermore, the Poisson's ratio of a tonalite was lower than that of a granodiorite, and assumed a negative value. This effect occurred because the lateral strain became positive as it changed from contraction at the initial stage of loading to extension at higher stress levels. There is no ready explanation for this phenomenon; it is believed, however, that it occurs due to microcracks pre-existing in rock materials and/or weak bonds between the adjacent mineral grains.
  • 張 聖徳, 坂根 政男
    2007 年 56 巻 7 号 p. 660-666
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    This paper studies the multiaxial creep-fatigue damage evaluation for SUS304 stainless steel at 973K. Strain controlled biaxial tension-compression low cycle fatigue and creep-fatigue tests were carried out using cruciform specimens under two strain waveforms at three principal strain ratios. The principal strain ratio is φ =εx/εy ; εx and εy are the principal strains in x and y directions, respectively. Low cycle fatigue and creep-fatigue lives decreased with increasing the principal strain ratio in Δεy constant tests. Cracks in creep-fatigue tests at larger principal strain ratio initiated earlier than those at lower principal strain ratio. Earlier and faster void growth was observed in creep-fatigue tests at larger principal strain ratio. An equation taking account of the contribution of x and y directional strains to void growth was proposed. Directional void growth and determination of two principal strain directions based on the void observations were discussed.
  • 中村 守正, 三浦 健一, 松岡 敬, 平山 朋子
    2007 年 56 巻 7 号 p. 667-674
    発行日: 2007年
    公開日: 2007/07/20
    ジャーナル フリー
    A new formula to calculate Adhesion energy W of DLC films was suggested on the base of Bull's model using Critical load Lc by scratch test in consideration of compressive residual stress σres in the film. Beside, a new Adhesion parameter J indicating Adhesion energy of the film was derived using fractured area ratio Rb by 180° bend test. Further, with DLC films practically deposited on SUS304 under the various deposition conditions by UBM sputtering, Lc by scratch test, σres by substrate curvature measuring test, Young's modulus EF by nano-indentation test, and Rb by 180° bend test were obtained. Validity of these formula and parameter for Adhesion energy were assessed by evaluating changes in Lc, σres, EF, Rb, W, and J with deposition conditions of the DLC films. Critical load Lc by scratch test changed significantly depending on the changes in mechanical property of EF, and Rb by 180° bend test changed with film thickness, were considered to be unreasonable as evaluating of film adhesion. While Adhesion energy W and Adhesion parameter J calculated by the formula suggested in this paper had a proportional relationship regardless of the deposition conditions. Both W and J were concluded to be derived appropriately for the evaluation of DLC film adhesion.
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