Journal of the Society of Materials Science, Japan
Online ISSN : 1880-7488
Print ISSN : 0514-5163
ISSN-L : 0514-5163
Volume 46 , Issue 8
Showing 1-19 articles out of 19 articles from the selected issue
  • Haruyuki KONISHI, Hiroshi KITAGAWA, Akihiro NAKATANI, Shigenobu YASUNA ...
    1997 Volume 46 Issue 8 Pages 880-886
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    Texture development caused by {111} ‹011› slips during plane strain compression is calculated on the basis of rate-dependent crystal plasticity theory. The polycrystalline model proposed by Asaro et al. is used for the expression of the behavior of aggregates. Two types of initial orientation distributions determined from recrystalized texture of Al-Mg alloys are used for the calculation. As reduction proceeds, deformation texture characterized by β-fiber devel-opment evolves, and the result shows good agreement with the experimental result of cold-rolled Al-Mg alloys. Finally the yield surface estimations are performed using the calculated texture. Strong in-plane plastic anisotropy caused by texture development is predicted from these results.
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  • Takayoshi NOSHO, Ichiro SHIMIZU, Takeji ABE, Masahiro WAKAYAMA, Kenjir ...
    1997 Volume 46 Issue 8 Pages 887-892
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    The free surface of polycrystalline metal becomes roughened in metal forming process due to its microscopic inhomogeneity. In the present study, two-dimensional surface roughness and three-dimensional microscopic shapes of the roughened surface of pure copper caused by compressive plastic deformation under a plane strain condition were investigated, and the characteristics of the microscopic deformation behavior during plane strain compression were clarified in comparison with those during uniaxial compression. It was found that the surface roughness increased almost in proportion to the applied strain, but the roughness measured in the compressive direction was larger than that in the transverse direction. This is because the mountains which appear on the free surface during plane strain compression tend to elongate in the transverse direction. The primary wavelength of the surface shape was also obtained by means of the maximum entropy method. The primary wavelength in the transverse direction was almost twenty times of the average grain size, and it decreased in correspondence with the applied strain. This implies that the inhomogeneity of deformation behavior of copper appears under the scale of twenty grains in the transverse direction.
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  • Yoji SHIBUTANI, Akinori TANIYAMA, Yoshihiro TOMITA, Taiji ADACHI
    1997 Volume 46 Issue 8 Pages 893-899
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    By the duplex effect produced by two kinds of phases of austenite and martensite, the transformation-induced plasticity (TRIP) steel is improved in ductility and fracture toughness. The strain-induced martensitic phase transformation could be associated with the strain localization behavior. Accordingly, the measurement of the amount of local transformation is necessary in order to construct a more physical evolution model in the constitutive equation. In this study, a new measurement system using a micro-hardness tester is proposed to obtain a volume fraction map of the martensitic phase expanding in the neighbor of strain localization. Then the system is applied to investigate the inhomogenous transformation behavior around the notch root of SUS 304 stainless steel bar under uniaxial tension.
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  • Fumihito NISHIMURA, Noriko WATANABE, Kikuaki TANAKA
    1997 Volume 46 Issue 8 Pages 900-905
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    The thermomechanical hysteretic behavior of an Fe-based shape memory alloy is phenomenologically analyzed under cyclic uniaxial tensile and compressive loading. The shift of the stress-strain-temperature hysteresis loop, expressed by means of the evolution of the residual strain, is well explained by the theory with some internal variables. The accumulated perfect dislocations formed as a result of the interaction of martensite plates is one of the internal variables introduced here. The back stress is also employed as an internal variable to be the driving force for the shape recovery for the martensite plates. The simulations describe well the hysteretic behavior under the strain and stress-controlled cyclic thermomechanical loading; the shift of a loop, evolution of the residual strain and the change in transformation stress.
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  • Mineo KOBAYASHI, Nobutada OHNO, Toshihide IGARI
    1997 Volume 46 Issue 8 Pages 906-913
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    Thermal ratchetting of 316FR steel cylinders subjected to the axial movement of temperature distribution is analyzed by implementing in finite element analysis three kinds of models, i.e., the elastic-perfectly plastic model, the Armstrong-Frederick model, and the Ohno-Wang model. The latter two models are specified in two forms, i.e., the combined kinematic and isotropic hardening form verified in a previous work and the kinematic hardening form with isotropic hardening neglected. It is shown that the analysis depends greatly on the models employed while it is influenced relatively little by the neglect of isotropic hardening. It is also shown that the Ohno-Wang model, which can express the closure of stress-strain hysteresis loops, gives good simulation of the experiments.
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  • Fusahito YOSHIDA, Tatsuo OKADA, Toshiaki SATO, Yasunori HARADA, Masano ...
    1997 Volume 46 Issue 8 Pages 914-918
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    The formability of sintered powder chromium plates of 99.8%-purity in roll-compression bending is investigated at various temperatures below the DBTT (Ductile-to-Brittle Transision Tempearture: 180°C for the chromium). In the roll-compression bending method for less-ductile chromium, roll-contact pressure is expected to prevent surface cracking, because high hydrostatic pressure increases ductility. However, on the first trial for monolithic chromium plates, a problem of this method was found from both the experiments and the FEM stress analysis that high tensile stress appears near the roll-contact region of the plate. To reduce the tensile stress there, steel-covered chromium plates were tested and were successfully bent at 80°C, whereas three-point bending was applicable only at the temperature above 130°C. It is thus confirmed that the roll-compression bending of steel-covered chromium plates is quite effective in decreasing the forming temperature.
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  • Hiroyuki KUROKAWA, Kazuyuki NAKASUJI, Haruhiko KAJIMURA, Takayuki NAGA ...
    1997 Volume 46 Issue 8 Pages 919-925
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    Metallurgically bonded transition joints which enable to connect reprocessing equipments made of superior corrosion resisitant valve metals (Ti-5Ta, Zr or Ti) to stainless steel piping are required for nuclear fuel reprocessing plants. The authors have developed dissimilar transition joints made of stainless steel and Ti-5Ta, Zr or Ti with an insert metal of Ta by the hot bond rolling process of clad bars and clad pipes, using a newly developed mill called “rotary reduction mill”.
    This report presents the manufacturing process of dissimilar transition joints produced from the clad pipe with three layers by the hot bond rolling. First, the method of hot bond rolling of clad pipe is proposed. Then, the mechanical and corrosion properties of the dissimilar transition joints are evaluated in detail by carrying out various tests. Finally, the rolling properties in the clad pipe method are discussed.
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  • Yoshiyasu ITOH, Masataka TAMURA, Yasuo TAKAHASHI
    1997 Volume 46 Issue 8 Pages 927-932
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    A computer-aided interactive system for coating design has been developed, which enables to analyze conveniently the reaction diffusion of bonded materials. The object of this study is the overlay coatings of MCrAlY alloy sprayed by a low-pressure-plasma spray (LPPS) process for protection against high-temperature corrosion and oxidation in the field of gas turbine components. However, the reaction diffusion behavior at the interface between the MCrAlY coating and the substrate, which has an important effect on coating degradation, has not always been clarified. Three kinds of substrate, such as equiaxis IN738LC, directional solidified CM247LC and single-crystal CMSX-2, and four kinds of low-pressure-plasma sprayed MCrAlY coating were selected for the experiments.
    The experimental results showed that the reaction diffusion layers consisted of aluminum compound layer and aluminum decrease layer, basically. However, the aluminum decrease layer could not be observed in the cases of CoNiCrAlY and NiCoCrAlY coatings. It was also indicated that each diffusion thickness changed in parabolic time dependence. And the order of reaction diffusion rate was NiCrAlY>CoCrAlY>CoNiCrAlY>NiCoCrAlY independent of the kind of substrate. It was also clear that the estimation of long time diffusion behavior by simulation analysis was possible in comparison with the experiments.
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  • Yasuhiro MIKI, Hiroji ARAKI, Tadashi TANIGUCHI, Yuji NISHIBATA, Masao ...
    1997 Volume 46 Issue 8 Pages 933-938
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    The residual stress and various characteristics of Ti-N films coated on the surface of SKH51 substrate by ion beam mixing technique were examined. As a result, it was found that the wear characteristic of the films in which Ti2N phase coexisted with TiN phase was better than that of the TiN single phase films, though the dynamic hardness of the former films was lower than that of the latter films. When a small amount of Ti2N phase existed in TiN phase matrix, both the residual stress and the particle size of TiN phase showed a minimum. As to the TiN+Ti2N two phase films coated with the same N/Ti supply ratio, the specific wear rate was decreased when the residual stress of the film was increased.
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  • Motofumi OHKI, Yoshiharu MUTOH, Takashi HIGASHIWADA, Shigeru ADACHI, M ...
    1997 Volume 46 Issue 8 Pages 939-945
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    Thermal cycle tests of thermal barrier coatings in vacuum were carried out to investigate the characteristics of thermal cycle damage and the effect of compositional gradient on thermal cycle damage. Surface cracks vertical to the coating surface were nucleated during thermal cycling, while no interlamellar crack along the interface between coating layers was found in vacuum. The compositional gradient significantly reduced the size and number of surface cracks nucleated during thermal cycle. This significant improvement in thermal cycle damage due to the compositional gradient results mainly from the improvement of material properties. No degradation of thermal barrier property during thermal cycling in vacuum was observed.
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  • Mamoru MIZUNO, Ken-ichiro ABE, Tatsuo INOUE
    1997 Volume 46 Issue 8 Pages 946-951
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    Metal matrix composite with the functionally gradient properties reinforced by particles are processed by centrifugal casting technique under various casting conditions, and the mechanical properties of the material are evaluated experimentally. In the process, SiC particles are mixed with Al alloy in advance, and they are cast into a mold turning at a given constant velocity. The particles are distributed inhomogeneously into the Al alloy matrix during solidification of the matrix due to the centrifugal force caused by the difference in density between the Al matrix and SiC particle. In order to estimate the functionally gradient properties of the cast composite, the volume fraction of the particle is evaluated from microscopic observation on the cross section, and the Young's modulus is measured by a tension test. As a casting condition, the angular velocity and initial temperature of the mold are changed, and the dependence of distribution of the properties on the casting condition is investigated. Then, the capability of the present casting technique to produce functionally gradient material is discussed.
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  • Yoshio ARAI, Eiichiro TSUCHIDA, Junji MIYAGAKI, Motoki YOSHINO, Mark J ...
    1997 Volume 46 Issue 8 Pages 952-956
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    Four point bending tests on Si3N4/SUS304 joints after thermal cycling were conducted and their fracture surfaces were examined by a fractographic method. Based on these results, the fracture path and the criterion for unstable fracture are discussed by a interface fracture mechanics approach. A crack initiates in the ceramic side very close to the ceramic/brazing filler interface; the unstable fracture occurs when K1 of the subinterface crack reaches KIC for the ceramic material. Consequently, strength degradation during thermal cycling is caused by micro-cracking.
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  • Nobuji KOYAMA, Masayoshi KITAGAWA
    1997 Volume 46 Issue 8 Pages 957-962
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    In order to know the fatigue fracture mechanism of FRP, quasi-static tensile and fatigue tests were performed at various temperatures using AS and PC samples with small content of short glass fibers, which were fabricated by injection molding. The following results were obtained. In tensile fracture, (1) for AS, the crazes initiated at the end of glass fibers parallel to the loading direction caused a final fracture, while at -192°C, fracture started at the crazes formed on the surfaces of the test sample, and (2) for PC, either of diamond shaped cracks and debonding initiated around the fibers initiated the tensile fracture, while at -192°C, tensile fracture occurred due to the surface crazes. In fatigue fracture, (3) for AS, the formation of crazes at the ends of glass fibers became the initiation site of fatigue fracture at the temperature range tested here and (4) for PC, under a relatively high stress amplitude at 25°C, crack growth from the shear cracks initiated around the fibers perpendicular to the loading direction caused fatigue fracture, but at relatively low temperatures, the surface crazes led to a final fracture.
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  • Masato MURATA, Wataru TAKAHARA, Jun-ichi SATO, Takeshi DEGUCHI
    1997 Volume 46 Issue 8 Pages 963-968
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    High temperature creep and creep-fatigue fracture behavior were investigated in air on two kinds of silicon nitride with different additives of MgO+Y2O3 and Al2O3+Y2O3. Fracture elongation was almost identical in the both cases of creep and creep-fatigue tests at 1673K in air for the two kinds of silicon nitride. The fracture surface was rough in the creep test specimens, while it was relatively smooth in the creep-fatigue test specimens. In the creep-fatigue tests, fracture lifetime was shorter than that of the creep tests. However, for the silicon nitride with MgO+Y2O3 the fracture lifetime in the creep-fatigue tests approached to the level of creep tests with increasing the hold time under no stress in the wave pattern. It seems that some intelligent function of the self-repairing of materials damage occurs in silicon nitride with MgO+Y2O3.
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  • Takaei YAMAMOTO, Masao SAKANE, Masateru OHNAMI, Yutaka TSUKADA, Hideo ...
    1997 Volume 46 Issue 8 Pages 969-975
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    This paper describes the multiaxial creep-fatigue of 63Sn-37Pb solder solid and tube specimens in push-pull and reversed torsion using fast-fast, slow-fast, fast-slow and slow-slow strain waves. The strain rate of fast straining was 0.5%/s and that of slow straining was 0.005%/s. The suitability of multiaxial strain parameters for correlating multiaxial creep-fatigue lives was discussed. Mises' strain and maximum shear strain were an appropriate parameter for the data correlation. The largest fatigue lives were found in fast-fast strain wave test and the smallest ones in slow-fast test. The fatigue lives in slow-slow test were somewhat smaller than those in fast-fast test, but there was no large difference in fatigue life between the two strain waves. Main cracks of which length was more than 1mm were initiated and propagated in fast-fast and slow-slow tests but many small cracks whose length was less than 100 micron meter were initiated and no long main cracks were propagated in slow-fast and fast-slow tests. These crack behaviors corresponded with the stress change with cycles. Stress amplitude rapidly decreased with cycles in the final stage of life in fast-fast and slow-slow tests due to the main crack extension but it gradually decreased with cycles in slow-fast test resulted by the extension of many small cracks. Deformation of grains in slow-fast and fast-slow tests was discussed in relation with the micro rachet deformation of grain boundaries.
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  • Ken-ichi HASHIMOTO, Youichi SUZUKI, Chikayoshi YATOMI
    1997 Volume 46 Issue 8 Pages 976-980
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    For a crack in an anisotropic elastic body subjected to remote inclined load under a plane stress condition, the energy release rate at the onset of crack kinking is analyzed by numerical analysis. The analysis is based on the path-independent E-integral using the finite element method. The E-integral gives the energy release rate at the onset of crack kinking for hyperelastic bodies. The eight-noded and six-noded isoparametric finite elements are used and the integral paths lie along the sides of the finite element. The numerical integration of the E-integral formula can be evaluated directly by using the nodal forces and nodal displacements. After the path independency is examined in an isotropic elastic body subjected to the remote constant tension stress, it is shown that the results for inclined loads agree very well with the results by Wu (1978). For the anisotropic bodies, in the cases of different planes of symmetry, the energy release rate is computed first under the perpendicular loading to the carck surface and then under the inclined loading. For the former, the results agree well with the perturbation solutions by Gao and Chiu (1992). For the inclined load, the direction of the maximum energy release rate is more sensitive to the direction of loading than the direction of the plane of symmetry.
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  • Q.S. BAI, Sumio MURAKAMI, Yasushi KANAGAWA, Kohhei TANAKA
    1997 Volume 46 Issue 8 Pages 981-988
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    A damage model for fiber-reinforced plastics (FRP) laminates with matrix microcracks and delamination is developed based on continuum damage mechanics (CDM) and modified lamination theory. The anisotropic damage state in each lamina due to matrix microcracks and the delaminations at each interface are described by different damage variables of second rank tensor. The elastic constitutive relations of matrix damaged laminae are derived first by use of the effective stress and the hypothesis of strain equivalence. Then the constitutive relation of each lamina is introduced into the modified lamination theory incorporating the effect of delamination. The resulting model is applied to CFRP angle-ply laminates, and both damage variables are identified by the measured densities of matrix cracks and delaminations, respectively. Comparison between the predictions and the experimental measurements shows the applicability of the present model to describe the influence of matrix cracks and delamination on the mechanical properties of angle-ply CFRP laminates.
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  • Makoto HAYASHI, Masahiro OHTAKA, Akisuke NARUSE
    1997 Volume 46 Issue 8 Pages 989-995
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
    Surface crack configuration can be detected by DC potential drop method. The simplified inverse method for determining the surface crack shape has been developed based on the FEM analysis for various deep surface cracks with different aspect ratios. The method has been applied to fatigue surface cracks introduced at the inside surface of stainless steel pipes. The cracks shape could be estimated with an accuracy of ±0.3mm in depth. In order to verify the method, a pipe internal scanner was devised for the measurement of potential difference distribution in 12 inch pipe. The scanner can pass through not only an elbow but also a vertical pipe. The crack position and the detailed crack configuration can be analyzed automatically from the measured potential difference distribution.
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  • Hiroyuki YANO
    1997 Volume 46 Issue 8 Pages 996-1002
    Published: August 15, 1997
    Released: June 03, 2009
    JOURNALS FREE ACCESS
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