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Kiyomitsu MAEDA, Takehiko SOMEYA, Byongjun LEE, Jun KOMOTORI, Masao SH ...
Article type: Article
Pages
295-296
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The purpose of this study is to investigate the effects of the physical vapor deposition (PVD) and gas-nitriding on the fatigue properties of titanium alloy (Ti-4.5Al-3V-2Mo-2Fe). Rotational bending fatigue tests were performed on five types of specimens; that are uncoated, TiN coated, gas-nitrided, annealed after TiN coating, and Ti-TiN coated. We obserbed the fracture process. The results are summarized as follows : 1) The fatigue strength of the gas-nitrided specimen was decreased less than that of the untreated and TiN coated specimens. This is because the matrix grain size increased because of a high temperature nitriding process (800℃ for 4 hours). 2). Fatigue limit of Ti-TiN coated specimens that was maked to progress fatigue strength of titanium alloy (Ti-4.5Al-3V-2Mo-2Fe) was decreased less than that of TiN coated specimens. This is because : firstly Ti coated surface was highly rough, secondly the thickness of Ti film was much smaller than that of diflusion layer of gas-nitrided specimen.
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Makoto HOSODA, Toshiyuki MESHII, Katsuhiko WATANABE
Article type: Article
Pages
297-298
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Near threshold fatigue crack growth (fcg) rate was measured under a stress intensity range (△K)-normalized crack length (a/W) relationship, equivalent to that for a circumferential crack in a thick-walled finite-length cylinder (which is suddenly cooled inside). The tests were conducted fundamentally in accordance with ASTM E-647. The objective of the experiment was to verify the validity of the thermo-elastic analysis for the crack by the authors. Tentative results showed that the threshold intensity range for the thermal-stress equivalent △K-a/W relationship was close to that obtained from that by standard ASTM K-decreasing near threshold fcg test.
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Shoichiro NAKAZAWA, Daisuke KANAMORI, Jun KOMOTORI, Masao SHIMIZU, Yos ...
Article type: Article
Pages
299-300
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In order to clarify the effects of super rapid induction heating and quenching process on fatigue properties of FDI (Ferritic Ductile Iron), rotation bending fatigue tests were performed. Measurement of thickness of martensite layer and observation of fatigue crack initiation and propagation were also carried out to investigate the fracture mechanism of the super rapid induction heating and quenching processed specimen.
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Kenji HATANAKA, Teppei SEIKI
Article type: Article
Pages
301-302
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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SUS304 stainless steel and cast austenitic stainless steel, of which matrix has the similar chemical compositions to those in SUS304 steel, were low-cycle fatigued under axial and diametral strain-controlled conditions at the test temperature 550℃. The relationships between inelastic strain amplitude △ε _<ins>/2 and fatigue life Nf, and stress amplitude △σ _s/2 and Nf showed that fatigue life is much shorter in cast stainless steel than in SUS304 steel. It was suggested from micro-structure observations that this is caused by the characteristic growth of fatigue crack initiated at inclusions and cast defects included in the cast stainless steel. Moreover, the much smaller strength was shown in the cast stainless steel than in SUS304 steel in cyclic stress-strain response determined from the test.
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Junji NODA, Hiroyuki AKEBONO, Daisuke YONEKURA, Jun KOMOTORI, Masao SH ...
Article type: Article
Pages
303-304
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This study was carried out to improve the fatigue strength of steel with many surface modifications. Wide Peaning Cleaning (WPC) process was developed recently. Three factors of high hardness, high compressive residual stress and deterioration of suface roughness are added on surface layer with WPC process, and it is said that these factors will define the fatigue strength. We estimated quantitately the effect upon the fatigue strength by these factors. Furthemore we presumed and verified the presence of the maximum size of dent that influences the fatigue strength. The analysis resuts were almost accordance with the experimental result and it is shown that the prediction of fatigue strength of the steel modified with WPC process.
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Haruo ENDOH, Naoto YAEGASHI, Yoichiro HIWATASHI, Tsutomu HOSHIMIYA
Article type: Article
Pages
305-306
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The imaging of the simulated surface-subsurface combined defect using photoacoustic microscope has been demonstrated. Simulated surface and subsurface defects are fabricated independently such that the former was drilled on a pure aluminum plate whereas the latter was machined with end mill. Specimen with subsurface defect alone was also carried out. The photoacoustic image obtained clearly showed the location and the size of both subsurface defect and the surface-subsurface combined defect. The photoacoustic method is useful for detection of the combined defect which is difficult to detect with present NDE techniques.
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Junji TAKATSUBO, Shigeyuki YAMAMOTO
Article type: Article
Pages
307-308
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Nondestructive measurement of the thickness of thin coatings was investigated. After examining some ultrasonic methods to measure coating thickness, we considered that arrival time difference method was a most simple and effective method to measure coating thickness. It was found that the incident ray from the coating surface reflects at the bottom surface, while the incident ray from the bottom reflects at the interface between coating film and substrate. The arrival time difference is therefore appeared between the ultrasonic waves emitted from the surface and the bottom of the specimen. By use of this time difference, we can estimate the thickness of thin foils and coating films.
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Seiichi NISHINO, Kazuaki SHIOZAWA, Fumio INAYOSHI, Hiroyuki SHINJIN, T ...
Article type: Article
Pages
309-310
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Nondestructive evaluation method of the density and mean diameter of pore in the material using wavelet analysis of scattering ultrasonic waves was developed. The relationship between ultrasonic characteristics (noise energy and center of the frequency) and pore characteristics (diameter and density) was determined by numerical calculations. From the experimental results, it was found that the pore characteristics can be evaluated from the wavelet analysis of scattering ultrasonic.
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Kimihiko NAITO, Yoshihisa MINAKUCHI
Article type: Article
Pages
311-312
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The contact pressure measurement between plates is investigated by means of an ultrasonic technique. At first, the relations between the contact pressure and the change of the round-trip propagation time by using a surface wave probe are obtained by compressing calibration blocks under various surface roughnesses. Next, when a rectangular plate on the plate is compressed under locally uniform pressure, the change of the round-trip propagation time is measured using the surface wave probe. From the relations between the calibrated and measured curves, the contact pressure distribution between plates is quantitatively obtained. The experimental results agree fairly well with the analytical ones. Thus, the proposed ultrasonic method is useful for the measurement of contact pressure.
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Makoto SANO, Kenji GOMI, Kensuke ICHINOSE
Article type: Article
Pages
313-314
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The handling of the yield strength by cyclic loading becomes a problem, when the metal fatigue is examined from the initial stage. There is an example of making the stress in proportion to the strain of 0.2% on cyclic stress strain curve to be the cyclic yield strength. This time, the validity of the fact is not described, though the similar handling has been done without asking ductility and brittleness of the material. It is whether yield strength elongation by the tension load happens under cyclic loading, and it seems to determine the propriety of the fact. It seems to determine the propriety of the fact by whether yield strength elongation by the tension load occurs under cyclic loading or not. The handling method of the cyclic yield strength is determined, if this problem clears, and in addition, it seems to be useful for the investigation of the fatigue phenomenon in the initial stage. Here, it is tried to obtain cyclic stress strain curve by the constructed measurement system.
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Kiyotaka SAKINO
Article type: Article
Pages
315-316
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Strain rate tests are performed for pure iron using a modified Hopkinson pressure bar system in a strain rate range from about 1×(10)^<-3> to 2×(10)^4/sec. In order to evaluate the strain rate dependency of the dynamic flow stress over the wide strain rate range, activation energy E(ι) for deformation of pure iron obtained by Aono et al. is used. The flow stress at higher strain rates above about 1/sec is controlled by a thermally activated process of a formation of kink pairs, however the flow stress below the strain rate is controlled by the thermally activated process of a interaction of moving dislocations with forest dislocations.
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Kiyoto TAKEI, Yasuyuki KATO
Article type: Article
Pages
317-318
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In this paper, the research of the plastic behavior is done by paying attention to the shear deformation under large deformation, not only the direction of principal axis simply rotates in the space but also the replacement of the line element of principal axis occurs together with the progress of deformation. Then, the relation between isotropic and kinematic hardening is being examined experimentally, and the rationality of the Natural Strain theory is verified to the given problem.
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Hiroaki KATORI
Article type: Article
Pages
319-320
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Katsuhiko MURASE, Takakazu ONDA, Tatsuya HIRAI, Hitoshi WADA
Article type: Article
Pages
321-322
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This paper describes the characteristics about the plastic collapse of thin-walled beams subjected to dynamic load. The basic equation of the visco-plastic constitutive relation was shown for the local buckling on the thin-walled members. The static function is necessary because visco-plastic term depend on the over-stress which is difference of dynamic and static stress. The expression of the function and experiments for static collapse for thin-walled members are studied.
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H. TOBUSHI, K. TAKATA, K. OKUMURA, M. ENDO
Article type: Article
Pages
323-324
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The behavior of the interface and the lateral to longitudinal stain ratio due to the stress-induced martensitic transformation (SIMT) were investigated in the regions of superelasticity (SE) and shape memory effect (SME) in a TiNi shape-memory alloy wire through the tensile test. The interface between a parent phase and a martensitic phase which appears due to SIMT during the loading process and its reverse transformation during unloading starts at both ends in the gripping parts of a wire and propagates towards the central part. When the two interfaces meet, SIMT completes.
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Atsuhisa SHIODE, Masataka TOKUDA, Tadashi INABA, Soichi SUGINO
Article type: Article
Pages
325-326
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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A shape memory alloy has various interesting characteristics. One of them is the so-called two-way shape memory effect which remembers both of shapes of the low and high temperature sides. Training is a way to give the two-way shape memory effect to SMA. In this research, the cyclic bending was applied to Ni-Ti shape memory alloy wire, and the two-way shape memory effect was observed and discussed.
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N. Okabe, M. Tsutsumi, H. Iwakuma
Article type: Article
Pages
327-328
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Shape memory alloy has the properties of the pseudoelasticity and the shape memory effect, therefore, shape memory alloy is applied to various fields such as industrial and medical materials. The objective of this work is to invastigate to investigate the effect of Cu content and heat temperature on pseudoelasticity of TiNiCu shape memory alloys. The results show that the transformation start and finish stress and strain energy are affected by heat temperature and Cu content.
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M. Tsutsumi, N. Okabe, H. Iwakuma
Article type: Article
Pages
329-330
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Shape memory alloys have the properties of the pseudo-elasticity and the shape memory effect. Therefore, shape memory alloys are applied to various fields such as industrial and medical materials. The objective of this work is to investigate the effect of Cu content and heat temperature on pseudo-elasticity of Ti-Ni-Cu shape memory alloys. It was found from the results that the transormation start and finish stress and strain energy can be estimated from Cu content and their dispersions of show Weibull distribution.
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Tatsumi INOMATA, Toshio SAKUMA, Uichi IWATA, Yasuo OCHI, Takashi MATSU ...
Article type: Article
Pages
331-332
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The shape memory alloy (SMA) is well known as functional material, and drawn attention to apply to various fields such as medical, engineering and so on. However for the farther extension of the SMA applications, it is necessary to improve functions and fatigue life. In generally, the method of hardening with cold working is treated to metal for improving the fatigue life. In this paper, the thermo-mechanical cyclic test for Ti-41.7 Ni-8.5 Cu SMA samples with different cold working ratio (10-40%) are examined, and the effect of cold working ratio on fatigue life is investigated. And the observations of fatigue fracture surface are carried out. As the result of this examination, it becomes clear that the fatigue life Ti-Ni-Cu SMA under the condition of thermo-mechanical cycles decrease with increasing of cold working ratio.
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Toyoaki TANBO, Hideki KYOGOKU, Shinichiro KOMATSU, Toru WATANABRE, Fus ...
Article type: Article
Pages
333-334
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Ti-Ni shape memory alloy (SMA) was fabricated by the spark-plasma sintering method using elemental powders. The sintering and heat-treatment conditions were investigated to fabricate superior SMA by this method. Also, the influence of Ni content on the thermo-mechanical properties was investigated. The density of the compact sintered at 1153K was the highest, and the relative density was 96.6%. The sintered compact improved greatly in mechanical properties and thermo-mechanical properties by the heat treatment. The more the Ni content, the higher the deformation resistance and the recovery stress. The solution-treated compact was more than 400 MPa in tensile strength and more than 5.5% in elongation at any Ni content, and the solution treated Ti-51.0at%Ni compact was 320 MPa in recovery stress.
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Minoru MATSUMOTO, Jinhao QIU, Junji TANI, Daisuke NIKAIDO, Yuta URUSHI ...
Article type: Article
Pages
335-336
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Fe-30Mn-5.5Si shape memory ally with added element of Co or Ge were fabricated. The transformation temperatures and shape recovery force of these specimens were measured. In Fe-(30-x)Mn-xCo-5.5Si(x=2∿15), reverse martnesitic transformation start and finish temperature, As and Af, increased with increase of Co content. Recovery force increased up to 2% of Co content and it was almost constant above 2% of Co content. In Fe-30Mn-(5.5-x)Si-xGe(x=0.5∿5), As decreased by Ge addition and shape recovery force decreased with increase of Ge content.
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Fumitaka MATSUBA, Tomohiro WATANABE, Kikuaki TANAKA
Article type: Article
Pages
337-338
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Austenite-start condition is studied experimentally under tension/compression-torsion stress state in an Fe-Mn-Si polycrystalline SMA after non-proportional pre-loading. When the specimen is subjected to a successive axial and shear loads, the martensite variants induced during loading transform back to the parent phase in the subsequent heating process. The austenite-start temperature, determined by monitoring the dilatation curves during heating, can be represented as an austenite-start plane in the axial hold stress-shear hold stress-temperature space. The austenite-start plane rotates around the temperature axis while the shear preload increases. The position of the plane in the stress-temperature space also changes, depending on the amount of shear load.
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Mariko Takahashi, Hideki Hosoda, Hiroaki Suzuki, Shuichi Miyazaki
Article type: Article
Pages
339-340
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Diaphragm type microactuators were fabricated utilizing a Ti-Ni thin film sputter-deposited on a Si wafer by etching the Si. The shape of the diaphragms is a square with the dimensions ranging from 1,200 to 200mm. The microactuators were subjected to cooling and heating to expand and flatten due to the martensitic transformation and its reversion, respectively, under various constant gas pressures. The shapes of the microactuators were measured at various temperatures by laser beam measurement method. The actuator characteristics such as the actuation distance and work output were measured as a function of actuator size and gas pressure.
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Masahiro Hirano, Makoto Taniguchi, Hiroaki Suzuki, Shuichi Miyazaki
Article type: Article
Pages
341-342
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Ti-Ni shape memory alloy thin films are considered to be an attractive material for fabricating microactuators. The r.f. magnetron sputtering method was used to fabricate the Ti-Ni thin films. The thin film was deposited on a Si substrate covered with oxide layers. To clarify the effect of heat-treatment on the actuator characteristics, three Si chips with Ti-Ni thin films were heat-treated at different temperatures. Diaphragm type microactuators were fabricated by an anisotropic etching method after heat-treatment at 773K, 873K and 973K, respectively. In order to evaluate the characteristics of each microactuator, a laser beam was used to measure the shape of the actuators at various temperatures upon cooling and heating.
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Koji OKANO, Hitoshi TAKAGI, Tetsuya YAGI, Hiroaki MISAWA, Shigeki MATS ...
Article type: Article
Pages
343-344
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In recent years, electronic devices are miniaturized, and we wish to develop microactuator. Ni-Ti shape memory alloy is a material adapted to micro actuator as it can keep high power/weight ratio if it's miniaturized. So, a lot of studies have researched on this field. But, the research on the performance of thin films for actuator specifically did not reported frequently. Therefore, in our study, we researched recovery behavior of Ni-Ti shape memory alloy thin films; it is important for its practical application into microactuator to research on recovery force and response behavior.
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Masafumi SENOO
Article type: Article
Pages
345-346
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Yasushi Niitsu, Sota Yamamoto, Tomo Ikebe
Article type: Article
Pages
347-348
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The Raman spectrum of silicon that is applied uniaxial stress in several directions are observed by micro-Raman spectroscopy in order to obtain the relation between the Raman shift and the local stress present. In this paper, the influence of stress-strain state on the Raman shift for {110} surface of silicon single crystal. From polarization selection rules, we can selectively observe eigenvalues of optical phonons in {110} face of silicon and determine the effect of the stress on optical phonons theoretically. However, the Raman shift depends on both stress-strain state and polarization configuration for {110} face. In our measurements, the uniaxial stress was applied to the samples which were oriented three different directions. The experimental results are good agreement with the theoretical estimations.
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Yuichi NAKAMURA, Ikuya FUJISHIRO
Article type: Article
Pages
349-350
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In the present study, elastic modulus of the order of GHz frequency were evaluated by measuring Brillouin scattering light under high pressure, employing a diamond-anvil high-pressure cell and a laser light scattering optical system. The sound velocity on transverse mode, longitudinal mode and elastic modulus were obtained for polyphenylether up to 4 GPa. The slope change in pressure-sound velocity diagram was confirmed at about 0.3 GPa. The change of elastic modulus by pressure from Brillouin scattering was larger than static one and its difference decreased with raising pressure. Application of a viscoelastic model with a volume viscosity for these features was attempted.
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Tadashi HASEBE
Article type: Article
Pages
351-352
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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This article describes quantum field theoretical approach which has been advocated by the author. Dipoler substructure formation is taken an example and the governing equation responsible for patterning is derived. In the derivation, Stratonovich-Hubbard transformation is introduced to evaluate the Feynmann path integral, which gives the partition function for a system of large number of dislocations, and the effective Hamiltonian is obtained.
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Shigenobu OGATA, [in Japanese]
Article type: Article
Pages
353-354
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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I discuss that an ab-initio molecular dynamics method for investigating deformation and fracture of materials. I also show a result of an ab-initio tensile testing simulation of an interface between aluminum and aluminum nitride.
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Shigeo KOTAKE
Article type: Article
Pages
355-356
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Jippei SUZUKI, Eitoku NAKANISHI, Kiyoshi ISOGIMI
Article type: Article
Pages
357-358
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The laser machining were carried out on unsatulated polyester by using CO_2 and Nd-YAG lasers. And the machined holes were observed to study the influence of the wave length of laser. The polyester was cracked by the heat shock and the hole was not formed by using YAG laser. The holes can be made by CO_2 laser without crack. The CO_2 laser machinings were performed by using some parameters, including irradiating time, power of laser and the defocusing, which influence the shape and size of the holes.
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Yasuyuki Suzuki
Article type: Article
Pages
359-360
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Masaomi Kinoshita, [in Japanese], Masahumi Senoo, Yasuyuki Suzuki, Sig ...
Article type: Article
Pages
361-362
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Shigeo KOTAKE, Yasuyuki SUZUKI, Masafumi SENOO
Article type: Article
Pages
363-364
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Yohei FUJIMOTO, Kimiharu KAYUKAWA, Akihito MATSUMURO, Kazuo SATO
Article type: Article
Pages
365-366
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Yoshiro SHIMOJO, Keiji KUSUMOTO, Tadashi SEKIYA
Article type: Article
Pages
367-368
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Relaxor-type ferroelectric perovskites Pb(Ni_<1/3>Nb_<2/3>)O_3-Pb(Sc_<1/2>Nb_<1/2>)O_3(PNN-PSN), though very difficult to obtain in single phase by the usual mixed oxide method, were prepared by a process consisting of heat treatment and then acid treatment of the oxide mixture containing PbO in amount greater than in the perovskite composition. For the crystallization of perovskite phase without the formation of pyrochlore phase and therefore with desirable composition, it was essential that the mole ratio of PbO to the perovskite composition is 2 : 1 or more and the calcination temperature is 950℃ or more. Removing the excess PbO by leaching with a 1N acetic acid solution, then the ceramic sintering was made at 1200-1360℃ in a PbO atmosphere. From the measurement of the dielectric constant against temperature, it was found that the Curie temperature linearly increased from PNN (-150℃) to PSN (100℃). The dielectric constant peak turned from broad to sharp and became higher with increasing PSN content. The actuator function was highly improved by the introduction of PbTiO_3 (PT) into PNN-PSN.
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Keiji KUSUMOTO, Yoshiro SHIMOJO, Tadashi SEKIYA, Satoaki MORI
Article type: Article
Pages
369-370
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Relaxor-type ferroelectric perovskites, (1-x)Pb(Ni_<1/3>Nb_<2/3>)O_3・xPbTiO_3 with x between 0.32 and 0.4,were prepared through process of heat treatment and then acid treatment of oxide mixtures containing PbO in amount greater than in the perovskite composition. The perovskite phases were crystallized without the formation of pyrochlore phase from the mixtures 5PbO+(1-x)NiO+(1-x)Nb_2O_5+3xTiO_2 at 950℃. By leaching with a 1N acetic acid solution to remove the excess PbO, the perovskite phases were obtained in discrete and cube-shaped particles of 1-5μm size. The ceramic sintering was made at 1180℃ for 3h. Relatively good dielectric and electromechanical properties were observed in the ceramics with x=0.34 to 0.39. The most remarkable was that the ceramic with x=0.36 showed a large longitudinal strain of 0.28% at 1600V/mm near room temperatures.
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Minoru MATSUMOTO, Hisamichi KIMURA
Article type: Article
Pages
371-372
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Shape memory ally Ti-Pd-Ni films were made by the melt spinning apparatus with a single roll of rapid solidification method. Obtained specimens were ribbon shaped films, 20∿30μm in thickness and 1mm in width. The structures of the surfaces were observed by an optical microscope. The crystal structures at various temperatures were studied by the X-ray diffraction. Preferred crystal orientation was observed in these films. The martensitic and the reverse martensitic transformation temperatures were determined by the temperature changes of X-ray diffraction patterns and a differential scanning calorimeter. These transformation temperatures were lower than that of bulk specimens. After annealing at 800℃, these transformation temperatures did not increase up to that of bulk specimens.
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H. Tobushi, S. Hayashi, K. Okumura, M. Endo
Article type: Article
Pages
373-374
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The main functional properties of shape memory polymer are shape fixity and shape recovery. Gas permeability is also observed in polyurethane-shape memory polymer. Shape memory polymer is light, shows large deformation and is easy to be formed. The glass transition temperature of shape memory polymer can be set around the room temperature. Shape memory polymer is expected to be applied as an intelligent material.
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Hisamichi KIMURA, Akihisa INOUE, Kenichiro SASAMORI, Yoshiharu WAKU
Article type: Article
Pages
375-376
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Al_<85>Ni_<10>Ce_5,Ti_<40>Zr_<10>Cu_<50> and Zr_<65>Al_<10>Cu_<15>Ni_<10> amorphous wires were produced by a newly designed method, i.e., melt extraction using a high frequency and an arc furnace. The wires have a circular cross section and a smooth peripheral surface, but small flaws are observed on the surface. The structure of the amorphous alloy wires is nearly the same as that of the melt-spun amorphous ribbons. The tensile strength and elongation are 930 MPa and 1.5%, respectively, for the Al_<85>Ni_<10>Ce_5 wire and 2000 MPa and 2.0%, respectively, for the Ti_<40>Zr_<10>Cu_<50> wire. The Zr_<65>Al_<10>Cu_<15>Ni_<10> wire has a large supercooled liquid region of 95 K, the coefficient of thermal expansion of 9.2×(10)^<-6> K^<-1>, tensile fracture strength of 1590 MPa and fracture elongation of 2.2%.
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Takashi TORIYAMA, Kazuya OGURI, Akira TONEGAWA, Yoshitake NISHI
Article type: Article
Pages
377-378
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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A crack-reduction EB treatment for carbon fiber, used without the traditional method of accompanying heat, was developed to modify the surface properties at lower temperature. The EB irradiation to reduce crack is new concept which can be broadly applied in the engineering fields of aerospace and rapid transit.
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Toshio HAGA
Article type: Article
Pages
379-380
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Clad strip casting was tried using a twin roll caster. The clad strip could be cast directly from melt. The two pieces of strips could be connected easily by very small force, for example, 5N/mm width. Interface between the strips was formed clearly, and two pieces of strips were connected strongly. To cast strongly connected clad strip, connecting surface had to be semi-solid condition. Both of overlay type clad strip and inlay type clad strip could be cast using the twin roll caster in this study. Wire could be inserted easily into the clad strip using this twin roll caster. The clad strip was rapidly solidified like a single strip. Casting conditions which affected the connection of the strips, the interface between the strips and diffusion of the element were investigated in the present study.
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Junro KYONO, Norio SHINYA
Article type: Article
Pages
381-382
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Long-time creep fracture in austenite stainless steels is caused by the initiation and growth of creep voids at grain boundaries during creep. Present work was intended to propose a healing process for the creep voids and improve the creep rupture properties. Addition of B, N and Ti and also removal of S in the 304 stainless steel promoted the precipitation of BN at surface of creep voids. This stable precipitation of BN showed the possibility of controling the growth of creep voids by the healing effect. It was thought that the extension of rupture life and improvement of ductility observed in the steel are attributed mainly to the healing effect.
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Mamoru Omori, Toshinori Isobe, Tomoko Shibuya, Toshio Hirai
Article type: Article
Pages
383-384
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The structure of eutectic composites consists of coupled single crystals, and their properties are expected to differ from conventional composites. Eutectic ceramics composites are fundamentally prepared form melt. The melting point of heat-resisting ceramics is near 2000℃. Unidirectional solidification is adopted to form eutectics without pores and cracks. The size and shape of the unidirectionally solidified are restricted, and not applied to complex large parts. The spark plasma system (SPS) makes it possible to consolidate materials in electric field. The eutectic powder prepared from solid was consolidated by SPS. Eutectic structure was reproduced, coupled crystals being joined each other and grown.
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Tsunemichi IMAI, Sumito KOJIMA, Numenori ONO
Article type: Article
Pages
385-386
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Hiromasa YABE, Kazuya OGURI, Haruhisa UCHIDA, Yoshihito MATSUMURA, Hir ...
Article type: Article
Pages
387-388
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The low magnetic field induced shape memory effect (MSME) was investigated of the Fe-45at%Pd thin film prepared by magnetron sputtering. The reversible relationship was obtained between shape change and applied magnetic field from earth magnetic field to 0.25 kOe. The high magnetostrictive susceptibility was detected at low magnetic field below 0.25 kOa at room temperature. The maximum magnetostrictive susceptibility was about 1.1ppm/Oe. It was higher than that of Tb_<0.3>Dy_<0.7>Fe_2 thin film developed.
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Y. Furuya, M. Wuttig, S. Yamaura, H. S. Kimura, T. Onoki, T. Watanabe
Article type: Article
Pages
389-390
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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In the ferromagnetic shape memory alloy actuator, magnetically induced twin variants grow and they are re-arranged along the favorable orientation to the external magnetic field. In this study, rapidly solidified Fe-30at%Pd alloy foil was by melt-spinning method. From the grain boundary character distribution (GBCD) analysis by SEM/EBSP, this rapid-solidified unique microstructures had strong crystal (100) plane anisotropy by fine columnar grain as well as high frequency low energy (small Σ-value) grain. Thermo-magneto-mechanical properties were measured by cantilever-type internal friction and mechanical spectroscopy equipment in the magnetic field strength controllable coil. Resonance vibration frequency, damping factor and magnetostriction were changed clearly depending on temperature and magnetic field strength. Short annealing for strengthening texture (i.e. crystal anisotropy) seems to work on larger magetostriction and it can be concluded that the repidly solidified, strongly textured ferromagnetic shape memory Fe-Pd alloy has the possibility of new type of giant magnetostrictive sensor/actuator at a narrow range of temperature near inverse As〜Af transformation point.
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Yasubumi FURUYA, N. W. Hagood
Article type: Article
Pages
391-392
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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The concept of design for "Smart Board" which combines the non-destructive magnetic inspection and shape recovery function in the material itself is proposed as one of the and then, we try to make the advanced composite material system. The developed ferromagnetic shape memory alloy will be used as the embedded fillers for reinforcement of composite board and magnetic Barkhausen noise (BHN) analysis will be applied as a magnetic non-destructive evaluation technique. Besides, self-repair and internal damage suppressing functions will be able to be realized by thermo-elastic shape memory effect of embedded SMA fillers.
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Kiyoshi MIZUUCHI, Masami SUGIOKA, Masao ITAMI, Yoshihira OKANDA, Kenic ...
Article type: Article
Pages
393-394
Published: July 31, 2000
Released on J-STAGE: August 01, 2017
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Aluminum alloy powder containing a 20vol% TiNi SMA alloy short fiber was hot-extruded into a composite. The microstructure and mechanical properties of the composite thus obtained were examined. Aluminum alloy powder containing 20vol% TiNi short fiber was easily extruded into a composite at 773K without blistering. A dense reaction layer 20μm thick was formed along the boundary between the fiber and the matrix by a heat treatment performed at 873K for 7.2ks after the hot-extrusion. The thickness of the interface formed at 873K increased from the outside of the fiber toward the inside with increasing heating time, and the structure of the interface changed from double to triple-layer type. The yield strength of the composite treated at 373K was higer by about 40MPa than that at 293K.
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