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Koichi ASADA, Takashi MATSUMURA, Takeshi KINOMOTO, Yasuo OCHI, Kiyotak ...
Article type: Article
Session ID: 913
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Recently, because the micro-machine is noticed and electronic equipments are made much lighter and smaller, the demand for micro materials is increasing. The researches for evaluating the mechanical properties of micro materials have been carried out. However the reliable data of the micro materials is insufficient, because the standard evaluation method of micro materials has not been established. In this study, the steel fine wires of austenitic stainless steel Type SUS304 were used as the material. Its diameter was 30, 50, 80, 200μm. The tensile strength tests were carried out. As the results, and Young's modulus increased with decreasing the diameter of specimen. Young's modulus got from linear sensor extensometer was corrected by JIS R 7606. This corrected Young's modulus was almost equal to Young's modulus calculated from the elongation of specimen by direct contact extensometer. Also, it was seen that the tensile strength increased with decreasing the diameter of specimen, and that the dispersion of the tensile strength increased with decreasing the diameter of specimen.
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Takeshi KINOMOTO, Takashi MATSUMURA, Koichi ASADA, Yasuo OCHI, Kiyotak ...
Article type: Article
Session ID: 914
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Recently, because the micro-machine is noticed and electronic equipments are made much lighter and smaller, the demand for micro materials is increasing. The researches for elucidating the mechanical properties of micro materials have been carried out. However the mechanical properties data of the micro materials obviously run short and the evaluation method of micro materials is different according to the researcher. Therefore, the establishment of the test method for the micro materials is very necessary. In this study, SUS304 thin sheets which thicknesses are 10 and 20μm were used. Specimens of which three kinds width are 0.1, 0.5, 2mm and three kinds of angle between rolling direction and loading axis are 0, 45, 90° were manufactured using etching method, and tensile strength tests were carried out. As the results, it was seen that tensile strength decreased with decreasing the width of specimen. Moreover, Young's modulus and tensile strength of the specimens that are different from angle between rolling direction and loading axis was affected by rolling direction.
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Nobuki UETA, Yuki SATO, Hideo MIURA, Kinji TAMAKAWA
Article type: Article
Session ID: 915
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Effect of structure of a micro slit formed in an electroplated copper film on the stress and strain fields at a tip of the slit was analyzed using a finite element method to improve the sensitivity of the stress measurement applying the film. When a penetrating slit is formed in the film, the maximum principal strain occurs at a surface of the film, while it occurs at the interface between the film and a substrate before the slit formation. The maximum principal strain at the slit tip increased drastically with increase of the film thickness and decrease of the tip angle of the slit. However, it did not change so much when the both length and width of the slit were changed. It is possible to improve the sensitivity of the stress measurement from about 100 MPa to about 10 MPa by optimizing the slit structure.
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Kinji TAMAKAWA, Sohei Fujishita, Hideo MIURA
Article type: Article
Session ID: 916
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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In order to improve the sensitivity of stress measurement using an electroplated copper film, mechanical properties of the film was measured using a scanning blue-laser microscope. The Young's modulus of the film was about a fourth of that of bulk material, and the tensile strength of the film was about 30% higher than that of bulk material. The surface roughness of the film after cyclic loading was about a tenth of that before loading. Formation of micro slits, 50μm long and 6 μm wide, in the film improved the sensitivity of the stress measurement. The minimum stress that causes the changes of the film texture after 10^8 cycle load decreased from 100MPa to 30MPa.
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Takao MIYAKE, Satoshi IZUMI, Shinsuke SAKAI, Hiroyuki OHTA
Article type: Article
Session ID: 917
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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In semiconductor devices, dislocations generated by high stress field provide electrical leakage. In this paper, we applied dislocation-dynamics simulator to SiN film stress field. Results are compared with the experimental results. Quantitative aspects of dislocation dynamics are discussed.
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Yoshio ARAI, Eiichiro TSUCHIDA, Kazunari OZASA, Akihiko YAMANE
Article type: Article
Session ID: 918
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Marked enhancement of photoluminescence of InGaAs/GaAs quantum dots(QDs) was observed by the nanoindentation of the light-collecting fiber nanoprobe onto the sample surface. In order to analyze its mechanism, calculations of the nanoprobe-induced strain and the energy-band profiles in the bulk GaAs surrounding InGaAs QDs have been performed on the bases of linear continuum elastic theory and six-band strain Hamiltonian. The calculations have revealed that the confinement potential for light holes was generated by the nanoprobe indentation. The results obtained in this study show that nanometer-scale strain modulation by nanoprobe indentation has potential for the investigation of semiconductor nanostructure physics.
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Masataka HASEGAWA, Kazuhiko SASAGAWA, Shigeo UNO, Masumi SAKA
Article type: Article
Session ID: 919
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Increases in current density and Joule heating due to scaling down of integrated circuits (ICs) deteriorate the reliability of the metal line. Electromigration might be one of the main damage of the interconnecting metal line and it leads to serious deterioration of the IC package reliability. The metal lines in IC are often connected by vias and such lines have the failure mode that the cathode edge of the line drifts in the direction of electron flow as a result of electromigration. Recently an expression of an atomic flux divergence due to electromigration at the line ends, AFD_<gen>|_<end>, was derived considering the boundary condition of the atomic diffusion at the line ends. In this study, the drift velocity is theoretically expressed utilizing AFD_<gen>|_<end> to construct the derivation method of the film characteristics in the governing parameter formula. By equating the theoretical drift velocity with measured one, the film characteristic constants are obtained. It is shown that the AFD_<gen>|_<end>-based method can appropriately determine the film characteristic constants.
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Hiromi SHIMAZU, Tomio IWASAKI, Hiroyuki OHTA, Kensuke ISHIKAWA, Takayu ...
Article type: Article
Session ID: 920
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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We studied stress-induced voiding under via-holes in copper-interconnect structures. The internal stress developed in copper interconnects was analyzed by using a finite-element method. The intrinsic stress of the construction materials was measured to analyze the internal stress. We investigated the relationship between the analyzed copper-line stress under the via-hole and the increase in resistance of copper-interconnect-structure test samples. By comparing the results, it was found that the increase in resistance due to the growth of stress-induced voids increased with the increase in the copper-line stress and the stress gradient. Therefore, the decrease in the copper-line stress and the stress gradient was important in suppressing stress-induced voiding.
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Akinori FUJINAMI, Shigenobu OGATA, Yoji SHIBUTANI, Kenichi YAMAMOTO
Article type: Article
Session ID: 937
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Process of a silica cluster on a polyimide surface is simulated by atomistic calculations combining the semi-empirical molecular orbital method and algorithms that can find the optimal path of a chemical bonding process. Specifically, we estimate the activation and sorption energies in the whole deposition. Among the limited number of process screening, we find that the chemical bonding occurs between a silica cluster and the polyimide substrate surface. In the adsorption processes, those reactions accompanying the Si-O bonding between the cluster and the polyimide are the most probable in the practical operation.
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Kenichi NAKANO, Hiroaki TANAKA, Shoichi SHIMADA
Article type: Article
Session ID: 938
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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In-depth investigations into nano-indentation play an important role in the full understanding of the deformation mechanisms of materials subjected to ultra-precision machining on the nanometer scale. This paper developed a reliable molecular dynamics model for simulating the nano-indentation of monocrystalline silicon carbide by some diamond hemispherical indenters that have different radii sizes. The research shows the size effect of indenter radius for deformation mechanisms. A phase transformation from its crystal structure to amorphous and a crack generation and propagation are observed with the smaller indenter radius, while a phase transformation to amorphous on a thin plane, stacking faults and crack generation and propagation are observed with the larger indenter radius.
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Hideo KOGUCHI, Takahiro AOKI
Article type: Article
Session ID: 939
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Molecular dynamic simulation and anisotropic elastic theory are employed to determine the elastic fields of surface steps and vicinal surfaces. The displacement field near a step of Fe is determined using atomistic simulation and FS potentials. The displacement produced by adding the displacement due to the surface dipole force to the displacement due to the variation of surface stress is shown to be in an excellent agreement with the simulation.
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Masahiro SANO, Hiroaki TANAKA, Shoichi SIMADA
Article type: Article
Session ID: 940
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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The paper describes a nano-bearing that is composed of carbon nanotubes analyzed by molecular dynamics simulation. To describe multiwall carbon nanotubes, Tersoff potential is applied for atoms in a basal plane of tubes and the Morse potential is for interlayer tubes, whose parameters are newly developed based on the equilibrium interlayer distance, the interlayer cohesive energy and the Young's modulus in the interlayer direction of graphite. The research shows the excellent possibility and properties of the nano-bearing composed of zigzag tubes It works on the wide range of temperature from 0K to 3000K, with high rotation speed and accuracy and in an ultra-high vacuum without any lubricant.
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Hiroaki ISHIDA, Satoshi MOTOYAMA, Kazuki MAE, Yasuaki HIWATARI
Article type: Article
Session ID: 941
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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The martensitic tarnsformations in alloys were studied using molecular dynamics (MD) simulations. The modified embedded atom method was used with the pseudo monoatomic potentials in which the angular dependence was taken into consideration. The thermally induced martensitic B2→3R tarsformations and the reverse 3R→B2 transformations have been obtained in the present MD simulations for NiAl alloy. The transformation is accompanied by a twin in the 3R phase which leads to a lattice-invariant deformation so as to minimize the transformation strain energy. The crystallographic orientation relationship, (001)_<B2>‖(001)_<3R> and [110]_<B2>‖[100]_<3R> was found, which agrees with experiments. The concentration dependence of the transformation temperature for Ni_xAl_<1-x>(0.58<x<0.69) alloys has been observed. The present MD simulation was carried with a medium-size of computational cell. The MEAM potentials are useful since they involve many-body effects through the electron density.
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Sergey DMITRIEV, Nobuhiro YOSHIKAWA
Article type: Article
Session ID: 942
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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We offer an atomistic model to describe copper/sapphire interface by means of simple interatomic potentials with a few fitting parameters. A successful result is achieved with the use of UBER functional form fitted to the results of rigid tensile test simulated from the first principles. The developed potentials are applied to simulation of crack propagation along oxygen terminated Cu(111)/Al_2O_3(0001) interface, where the dynamics of dislocations emitted by the crack tip are analyzed.
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Kouichi Tanaka, Takasi Miura, Nobuhiro Takezawa, Toyoshiro Inamura
Article type: Article
Session ID: 943
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Masatoshi YAMADA, Takashi MIURA, Nobuhiro TAKEZAWA, Toyoshiro INAMURA
Article type: Article
Session ID: 944
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Koichiro YAMADA, Kyoji HOMMA, Tsuyoshi HASHIMOTO, Daisuke MISHIMA, Nob ...
Article type: Article
Session ID: 945
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Renormalization Group Molecular Dynamics (RGMD) has been proposed in which viscosity caused by atomic motion in and between clusters were taken into account. Then the valilidity of the RGMD is checked using Molcular Dynamics in case of tensile fuacture of single-crystal Silicon. It has been shown that appropriate motion of clusters with internal quantities can be obtained using the RGMD by taking into account a viscosity.
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Yuusuke KOJIMA, Takayasu WATANABE, Kouichirou YAMADA, Nobuhiro TAKEZAW ...
Article type: Article
Session ID: 946
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Nobuhiro Takezawa, Koichiro Yamada, Toyoshiro Inamura
Article type: Article
Session ID: 947
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Ken-ichi SAITOH, Yuki TATEOKA, Noboru SHINKE
Article type: Article
Session ID: 948
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Scale difference of interface strength is discussed based on results obtained by two genuine particle methods. Microscopic method is molecular dynamics (MD) method, and another, microscopic one, is smoothed particle hydrodynamics (SPH) method. Our materials interface model is constructed as bi-material (aluminum, steel, or copper) composite with flat joint surrounded by free surfaces. In SPH analysis, three-dimensional elastic constitutive relation is built in, with employing two kinds of macroscopic materials constants. MD analysis is constructed by simple Lennard-Jones potential. In spite of difference in size, both particle methods can reproduce adequate characteristics of stress concentration along interface theoretically predicted in elastic regime. It is found that in SPH method tensile stress is transmitted with oscillation, and this will offer nice matching with molecular vibration in MD method.
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Katuyuki TOKIMASA, Tadahiro TANI
Article type: Article
Session ID: 949
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Fully reversed constant strain amplitude PC and CP tests were conducted on 316LC austenitic stainless steel thin-walled tubular specimens at 1023K in air under proportional push-pull and cyclic torsion loadings. The experimental data were analyzed based on the strainrange partitioning concept, and the partitioned equivalent inelastic strain range Δε_<ij> versus life N_<ij> relations (ij=pc,cc) were obtained, and the values of multiaxiality factor MF at the peak equivalent stress were determined for all of them. The effect of stress state on the partitioned inelastic strain range versus life relations was examined by comparing the results obtained in the present study with
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Toshihiro MITA, Masaaki MISUMI, Masafumi Okubo
Article type: Article
Session ID: 950
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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The linear relation on the semi-log plane between the log k and stress index n in Norton equation d ε/dt=kσ^n was recognized for residual compressive stress relaxation behavior of an induction hardened steel. This linear relation k=BA^n (A,B: experimental constants) could be expected also in high temperature creep phenomena. Investigating many references in latest two decades, this study widely verified the stress index n relation for various kinds of materials of ferrous metals, nonferrous metals, and ceramics ad also for compressive creep behavior.
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Toshiyuki KITAZAWA
Article type: Article
Session ID: 951
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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This paper is concerned with a compression experiment in the case of equal eccentric at the upper and lower ends of carbon steel square pipes with a circular hole in a short column range, supported by a spherical seats. The circular hole position is at random. Consideration has beengiven too the formula which is combination of the analysis besed on the energy method with the experimental results. The measurement results show that the formula is in good agreement with those obtained experimentally for a short column range.
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Seiichi OHTAKI
Article type: Article
Session ID: 952
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Torsion of bars with uniform cross-sections has been studied by many researchers, and the problem is well known as Saint-Venant torsional one. However, a few researchers have investigated as three dimensional problem. In this paper, the author conducted numerical simulation of torsion test by the finite element method using finite element software. Numerical examples are shown for typical four kinds of cross-sections. Tortional moment and twist angle per unit length subjected to concentrated loads at the end of the bars are compared with analytical solution. Finally, the validity of saint-Venant problem is proved.
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Koji FUJIMOTO
Article type: Article
Session ID: 953
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Sinusoidal cracks are often observed in internally pressurized tubes or thermally quenched glasses. In this study, stress intensity factors were analyzed for a single sinusoidal crack or periodically situated sinusoidal cracks in an infinite plate using the method of continuously distributed dislocations model. As the applied stress at infinity, not only the uniaxial tension but also the biaxial tension was considered. This paper shows the calculated stress intensity factors ratio K_<11>/K_1 and the direction of the crack propagation is investigated. As the result, it has been clarified that when periodically situated sinusoidal cracks are under biaxial tension, they will be likely to propagate to the direction which increases their amplitudes.
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Motoya MIZUTANI, Masataka TOKUDA, Tadashi INABA, Syuitirou MAKINO, Kou ...
Article type: Article
Session ID: 954
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Superplasticity of polycrystalline metallic materials is a phenomenon which shows hundreds to thousands of percents of large plastic deformation in axial tensil loading without necking in a steady state of low stress. In this research, the possibility of superplastic deformation in a magnesium alloy (AZ31Mg alloy) was experimentally investigated. In this paper, the details of experimental result as shown and discussed. Moreover, the constitutive equations of Mg alloy are proposed on the basis of the experimental results.
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Hiroyuki KATO, Nobuki INAGAKI, Kazuaki SASAKI
Article type: Article
Session ID: 955
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Shape-recovery stress due to shape-memory effect can be utilized as a power source of SMA-based actuators. Based on experimental and modeling analysis, this study examines the magnitude of the recovery stress in a Nickel-Titanium shape-memory alloy (SMA). When the shape change of a martensite is blocked and the martensite is heated to a temperature above the Af, recovery stress develops to be larger than the stress for superelasticity at the temperature. This result cannot be explained by early works on constitutive equations of shape-memory effect (Tanaka 1986, Brinson 1993). It is found that the one-dimensional model proposed by present authors (Kato, Inagaki, Sasaki 2004) gives a close estimate on the magnitude of recovery stress and its dependence on the prestrain given to martensite.
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Kazuyuki TSUTSUMI, Tomokazu NAKAGAWA, Kiminori NAKAYAMA
Article type: Article
Session ID: 956
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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It is well known that large plastic deformation occurs during the phase transformation in a cooling process of the steel. Because this phenomenon (called a phase transformation plasticity) has great influence on mechanical behavior of the steel, it is important to formulate it in order to calculate the deformation and residual stresses precisely. To obtain a phase transformation plasticity coefficient, we developed a simple experimental method using a three-point bending test under constant cooling rate. From experiments, the relationship between transformation plasticity coefficient and cooling rate is determined and formulated. Also, residual stresses in a steel slab are numerically predicted using this formula.
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Toshiyasu SUEYOSHI, Koichi ITO, Moriaki GOYA, Chobin MAKABE
Article type: Article
Session ID: 957
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Hill's plastic constitutive equation for anisotropic materials was formulated based on the coordinate system whose axis directions coincide with those of principal axes of material anisotropy. Then, it has been reported in the past that the principal axes of material anisotropy rotate by the added plastic deformation and do not coincide with those of the initial material. Thus, several models for taking into account the rotation of the principal axes of material anisotropy have been investigated. In this report, we proposed a revolution law of the rotation of the principal axes and incorporate the revolution law into the constitutive equation proposed by Goya & Ito that describes the directional dependence of the plastic strain increment on the stress increment.
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Makoto OGASAWARA, Atsushi SAKUMA, Takeyuki MORIUCHI
Article type: Article
Session ID: 958
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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It is neccessary to valuate viscoelasticity which is observed in moisture or polymer materials for the analysis of nonlinear deformation. The typical analysis technique which uses generalized viscoelastic model generally needs much effort in the valuation. On the other hand, it was already shown that the deformation can be represented by adding the state dependency to the component of simple three-element-solid model. As pointed out in the previous report, the dependency can be valuated by tensile test with three strain rates. However it did not go far enough to consider the deformations of real materials. This paper represents the experimental resuluts achieved from the tensile test of biological soft tissue. And the non-liner visco-elastic constitutive relation is valuated, from the results.
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Yoshio NAKAYAMA, Takao MORI
Article type: Article
Session ID: 959
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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The finite element analyses for automotive door model made of steel were performed in order to evaluate both structural and environmental performances. It is confirmed that the thickness of each panels consisting of door model affects on both performances. There is the optimum thickness considered both performances, and it can be decided by the design concept. The results of these analyses are useful for deciding that optimum thickness.
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Kenji ODA, Kazuaki Sasaki
Article type: Article
Session ID: 960
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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In the range of infinitesimal deformations, the Lagrange's classical plate theory is widely used as a plate bending theory, but it is applied to thin plate only. Then, for thick plate improved theories in consideration of transverse shear are prepared. In the range of large deformations, in-plane deformation of plate is produced with large deflexion. Because magnitude of this deformation depends on plate thickness, we cannot explain the influence of plate thickness with transverse shear only. In this paper, we investigate the influence of plate thickness on large deformation of plate and the applicability of analytical result of the thin plate to thick plates on large deformation. Examples for analysis are uniformly loaded several thick circular plates is analyzed using finite-deformation theory. As a numerical method, the 3-dimensional finite element method which is formulated using the incremental theory based on the convected coordinates is used.
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Atsumi OHTSUKI, Mikio YAMAKAWA
Article type: Article
Session ID: 961
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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This report deals with the large deformation of thin cantilever beams of nonlinear materials, subjected to a concentrated load at the free end. Because of the large deformations, both geometrical and material nonlinearities arise. Applications of the elastica theory have been confirmed to materials with linear stress-strain laws. In this report, the stress-strain relationships of the materials are represented by the Ludwick relation in considering the material nonlinearitiy. Theoretical analyses are compared with the experimental data. The agreement is found to be fairly close
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Peizheng LIN, Kunio KOKUBO, Kazuo ICHINOSE, Masaaki SAKAKUCHI
Article type: Article
Session ID: 962
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Plastic buckling in a predetermined annealed area of a pipe under an axial compressive load is applied to a structural fastening system. Estimations of buckling deformation, load and post-buckling behavior are very important, because the buckling deformations are used as the backside head of the application, and the post-buckling behavior affects reliability ad strength of fastening system.
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Mitsuteru NOMOTO, Yoshihiko YOSHIZAWA, Masao HASHIMOTO
Article type: Article
Session ID: 963
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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The research on uniform bending of beams which are not perfectly plastic body being composed of an unsymmetrical cross section with respect to its centroidal axis will be reduced to extremely complex results. The present report deals with uniform bending of beams having T-type cross section and a constant modulus of strain hardening in order to systematically account for characteristics of the bending.
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Yuuichi AOKI, Kiyoshi KUROHATA, Kouji YAMADA
Article type: Article
Session ID: 1101
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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A new type torque limiter for the continuous variable displacement compressor has been developed. The limiter should meet conflicting requirements of strength under normal operating conditions on the one hand, and limiter characteristics on the other. This technology was achieved by special metal and special limiter shape. As a result, it has achieved various superior characteristics, such as accurate limiter torque and light weight. One of the reasons is that limiter torque hardly vary with temperature and deformation velocity.
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Hidenori YOSHIMURA, Akira TAOKA, Katsuhiko MRAKAMI, Yoshihiro SUKEGAWA ...
Article type: Article
Session ID: 1102
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Metallic hollow sphere structure (MHS structure) is one of ultra-light porous metals. The ultra-light structure has a possibility to save the fuel consumption because car body can be lightened without reducing the rigidity and the performance of absorbing collision energy. Although the structures are made by powder metallargy in the conventional method, we propose a new method, in which MHSs are combined by adhesive bond. This method has advantages over the conventional one because the structures can be easily inserted into the car parts. To apply the structure by the proposed method to the car parts, the mechanical properties of the structure are measured. By compression test it is proved that the energy absorbing charactoristies is very high for the structure in which the MHS is filled in a thin walled pipe (0.1mm).
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Takanori Nagashima, Sayaka Oono, Eiji Yuasa, Yoshinari Oki
Article type: Article
Session ID: 1103
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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To recycle of turning chips of magnesium alloy, powder mixtures, which zinc and aluminum powder was added with various contents to turning chips of AZ31B alloy, were carried out mechanical alloying (MA) for various milling times. When Mg-30mol%Al-30mol%Zn powder mixtures were mechanically alloyed for 54ks, an i-icosahedron Mg_<49>(AlZn)_<32> phase, as called the quasi-crystal, forms and Vickers hardness of the powder particle is about Hv=300. Moreover, Mg_<17>Al_<12> or Mg_2Zn_2 phases also forms together with Mg_<49>(AlZn)_<32> phase in the case of high aluminum and zinc contents. Obtained MA powder was mixed to AZ30B alloy chips with various contents and then extruded at various temperatures. Mechanical properties and structural change in the extruded alloy are investigated.
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Shin-ichi MATUOKA, Motoki OGURI, Tutomu MURAI
Article type: Article
Session ID: 1104
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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The effect of zine and Al content on extrudabillity of Mg-Al-Zn system alloys have investigated. And it turns out that this has big influence on the mechanical properties of an alloy. Example, Manganese has the effect of increasing the tensile strength, 0.4% proof stress and elongation.
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Seiichi MASA, Shin-ichi MATSUOKA, Toshirou YAGO, Norio FUTAKUCHI
Article type: Article
Session ID: 1105
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Wear Resistance of hard-coated die on aluminum extrudability have investigated. Nitrided layer was prepared by radical nitriding method, and the 3μm hard coat films, TiAlN were by arc ion plating. In the case of nitrided die, whole coated area was oxidized, scraches (depth:max180μm) had occurred in the direction of extrusion and roughness (Ra) was increased after 20 extrusions. On the contrary, the roughness of the coated area with TiAlN films hardly changed after 40 extrusions. TiAlN coated die showed higher durability in comparison with dies coated with nitrided, because of the higher oxidation resistance of TiAlN.
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Hisashi IMAI, Shin-ichi MATSUOKA, Yuuichi AOKI
Article type: Article
Session ID: 1106
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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The ultrasonic welding technique can be carried out in many different ways, such as in direct welding. And the ultrasonic welding method is expected as the substitution of brazing or welding. For example, the ultrasonic welding of A1050H24/A1050O can be accomplished under the condition of 8MPa and 2.0s. The welding energy effectively works in the ultrasonic welding method using mild materials and narrow pressurization area. Oxide film and organic film are removed bonded interfaces periodically by the vibration of ultrasonic wave.
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TOMOAKI ISHIKURO, Shinichi MATSUOKA
Article type: Article
Session ID: 1107
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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This paper gives a description of an experimental study of ultrasonic welding of aluminum and alumina by using inserts. For example, the ultrasonic welding of 5N-Al sheet (0.2t) and anodized aluminum by means of vaporized aluminum (5N-Al, A1050, A2017, A6061, A7075) as inserts can be accomplished under condition of 5MPa and 0.1s. With the exception of vapor-deposited 5N-Al film, the vaporized film used for auxiliary purpose played a role of binders to facilitate welding, with short welding time and with low welding pressure, but much difference in welding strength was not found the welds with each aluminum alloy.
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Hiroshi KURATA, Kaoru HARA, Toshiyuki YASUHARA, Naoto OHTAKE, Hiroya M ...
Article type: Article
Session ID: 1108
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Carbon nanotubes (CNTs) and Carbon nanofibers (CNFs) are expected to be a new functional material. Moreover polymer matrix composites filled with CNT or CNF is expected as structural members like a space frame for automobile and bicycle as well as mechanical components for aerospace fields. In this study, we tried to form a pipe-shape molded CNT composite by extrusion molding set up designed for CNT composites. Extrusion molding is a low cost and continuously process. We can control an orientation of CNT with shear stress that is occurred by extruding flow and alternated rotation of inner and outer dies. In this way, we can give directionality of mechanical properties to products. Orientation of filler is observed when conventional carbon fibers are filled as a tracer.
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Shu FUJIWARA, Kazuki ENOMOTO, Toshiyuki YASUHARA, Naoto OHTAKE, Hiroya ...
Article type: Article
Session ID: 1109
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Carbon nanofibers(CNFs) and Carbon nanotubes(CNTs) are expected to be fillers of polymer matrix composites. We have measured thermal conductivity of polypropylene(PP) matrix composites filled with vapor grown carbon fibers (VGCFs) and vaper grown carbon nanofibers(VGNFs). Specimens were fabricated by injection molding with changing the concentration of the fillers in the composites from 0 to 50wt%. Thermal conductivity increased with increasing the filler concentration and the value of 3.46W/mK was obtained when VGCF concentration was 50wt% with highly oriented along measuring direction of thermal conductivity. This value is approximately seventeen fold higher than that of the pure PP(0.20W/mK).
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Kazuki ENOMOTO, Norifumi SATO, Toshiyuki YASUHARA, Naoto OHTAKE, Hiroy ...
Article type: Article
Session ID: 1110
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Carbon nanofibers (CNFs) can be considered a kind of carbon nanotubes (CNTs). This paper describes about dispersion of CNFs in the polypropyrene matrix composites and mechanical properties of specimens fabricated by injection molding. Dispersion of CNFs in the composites is quantified by the residual cluster rate and the maximum cluster size. The residual cluster rate is almost constant when the kneading time is 5min. or more, but the maximum cluster size slightly decreases with the kneading time. Young's modulus of the composites fabricated on the optimal conditions obtained from the relations between the mechanical properties and the kneading conditions was 1.4 times higher than that of neat PP when the CNF content was 10wt%.
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Tamotsu MURAKAMI, Taku YADA, Kazuhisa TAKUMI
Article type: Article
Session ID: 1120
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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This paper proposes a new stereolithography using liquid photo-initiator and base resin (photopolymer resin without photo-initiator) separately. First, base resin is supplied as a layer, and then a mask pattern is drawn onto the surface with photo-initiator using inkjet printing. When the surface is exposed with a UV lamp, only the drawn pattern is cured by the photo-initiator. In this process, the photo-initiator works as a positive mask and the uncured base resin can be used again because it is not mixed with the photo-initiator. The merits of this method are: (a) an area exposure instead of dot scanning enables fast fabrication, (b) no use of a mask device such as LCD or a laser leads to low cost, (c) keeping the base resin and photo-initiator separately leads to longer pot life of materials, (d) low viscosity and no curability of liquid photo-initiator itself enable more stability and liability of inkjet process, and (e) colored photo-initiator enables color fabrication. The basic idea, fabrication system implementation and the results of some fabrication experiments are presented.
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Kenichi HANYU, Masashi TAMURA, Terutake HAYASHI, Katsuhiro MAEKAWA
Article type: Article
Session ID: 1121
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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Recently, it has been recognized that treatment using regenerative medicine is a powerful tool for bone diseases, in which osteoblasts or osteogenic cells contained in transplant materials lead to the rebirth of positive bone tissue. The aim of this research is to manufacture artificial porous bones with titanium for the substitution of autologoas bones. Although the Greentape Laser Sintering (GTLS) method can be utilized for this purpose, some problems have arisen, including presice control of porous structures and dimensional accuracy. The main reason is the quality of the greentape. The mask printing method is successfully applied to the forming of a thin greentape with uniformly distributed titanium powder.
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Katsuhiro MAEKAWA, Yoshiaki WATANABE, Terutake HAYASHI
Article type: Article
Session ID: 1122
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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In this paper, a frequency analysis is introduced to distinguish geometric features included in three-dimensional objects such as pottery. The surface topography is then analyzed by the first Fourier transformation to plot a correlation between its power spectra and the spatial frequency that is defined by the number of waves per unit distance. The frequency characteristics are then utilized to design surface texture of an artificial 3D object. The artifact with such kansei texture is made substantial by using stereolithography, which is followed by the SD evaluation to see how it works form a kansei point of view.
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Masao KOHZAKI, Takeshi SAKAKI, Katsuya MATSUMOTO
Article type: Article
Session ID: 1123
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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In this work, the films have been prepared on silicon substrates by DC magnetron sputtering using a sintered B_4C target in Ar plasma. The DC power was fixed at 250W, ad the substrate temperature was varied from 50 to 250℃. The influences of H_2 addition as a plasma gas on the nano-indentation hardness, the adhesive strength and the friction coefficient of the films were investigated. Nano-indentation studies show that the film prepared at 250℃ without H_2 addition possessed high hardness of GPa. H_2 addition had the small effect of lowering the hardness and the adhesive strength of the film to the substrate was improved significantly by H_2 addition. Therefore, H_2 addition in the film formation process is effective for producing thin films containing boron with high hardness and high adhesive strength.
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Masaya KUROKAWA, Toru MINAMI, Naoto OIKO
Article type: Article
Session ID: 1124
Published: September 04, 2004
Released on J-STAGE: August 01, 2017
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The surface of a polymethylmethacrylate (PMMA) plate was irradiated by synchrotron radiation for patterning 15×15 clusters with spacing of 100 micron meter, and each cluster being constituted of 30×30 pieces of well that shaped with 10 micron meter diameter and that aligned with a pitch of 30 micron meter. By moving a x-ray mask systematically during this patterning process, micro structures having an optional side-wall inclination could be established on PMMA plate. The distance between the x-ray mask and the PMMA plate also was found to be one of the important factors for determining the side-wall inclination due to the effect of x-ray diffraction. On the basis of the patterned PMMA plate, used as a master plate, a nickel mold part was made by electro-forming process. The process proved to be effective in producing the Ni-made mold part having replicated micro-patterns with aspect ratio 1.7 (10 micron meter diameter and 17 micron meter height) on the surface. Then, the mold part was inserted in a mold base and polystyrene (PS) was injection molded to produce micro-well PS plates. By selecting suitable molding conditions, it was clarified that the PS chips with excellent transcription for patterns of the mold part without warp can be mass-produced by this method.
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