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Volume 56, Issue 10
Displaying 1-17 of 17 articles from this issue
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Teruo Asaoka, Taisuke Kamimura, Hideo Saito, Yoichi Ishida1992 Volume 56 Issue 10 Pages 1111-1117
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of hydrogen on the cyclic shape memory behavior of Ti-Ni alloy has been studied. A cyclic test machine was constructed. As the result, shape memory recovery stress and recovery % decreased with a small amout of hydrogen absorption. After degasing of the hydrogen following the cathodic charge, recovery stress and recovery % approached the level of a hydrogen-free specimen. The rate of this approaching depended on the amount of cyclic strains. During deformations at martensitic phases, no effect of hydrogen was observed on the coalescence of martensite variants. The decrease in recovery stress under mild hydrogen conditions, in which no hydride has been formed, was attributed to interactions between mobile hydrogen and dislocation introduced by the cyclic deformations.View full abstractDownload PDF (1007K) -
Takashi Maeda, Masanori Hosomi1992 Volume 56 Issue 10 Pages 1118-1126
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSHot working in the high temperature single α phase region have been employed to achieve a fine equiaxed lamellar grain structure in an α2+γ type Ti-Al intermetallic compound, which is expected to be the optimum microstructure for balancing the mechanical properties, such as room temperature ductility, fracture toughness and high temperature strength. Effects of hot working parameters, such as temperature, reduction and strain rates, and the subsequent cooling rate on the microstructures were systematically examined in the Ti-40 mol%Al alloy. The microstructures were characterized by the hardness measurement, X-ray diffractometry, optical microscopy and TEM.
It was clearly demonstrated that the refinement of fully lamellar grain structure is possible with the above method. It was revealed that the critical cooling rate for the formation of γ phase exists at 0.2 K/s when the alloy was deformed by 60% with 10−2s−1 at 1473 K. Parameters of hot working also strongly influence the lamellar grain size. Lower temperature, higher reduction and higher strain rates respectively promotes the refinement of lamellar grain size and an optimum combination of the working parameters produced the grain size of 100 μm. Furthermore, an isothermal process for the precipitation of γ phase after quenching into the α2+γ region achieved the grain size of 70 μm. The formation of γ phase in the α phase during continuous cooling and the role of hot working in the α phase on the eventual lamellar grain structures were discussed.View full abstractDownload PDF (3881K) -
Hiroshi Haji, Toshiaki Morita, Hideharu Nakashima, Hideo Yoshinaga1992 Volume 56 Issue 10 Pages 1127-1131
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to investigate the effects of organic contamination for Au-Al wire bonding, IC samples were contaminated in the out-gas from the conductive bond which is used in the IC assembly process. And a part of them were cleaned by Ar ion etching. These samples were analyzed by Auger electron spectroscopy and wire-bonded. Thin ・lms of the wire-bonded samples were prepared by microtome technique and observed by transmission electron spectroscopy. The effects of heating were also investigated by scanning electron spectroscopy and shear test. The results obtained are as follows.
(1) At the whole interface of the cleaned samples intermetallic-compound phases are observed, whereas at the interface of the contaminated samples a contamination layer is observed in some places instead of the intermetallic-compound. (2) The cleaned samples are generally higher in shear strength than the contaminated samples. (3) Both the contaminated and the cleaned samples have similar features for the change in shear strength due to heating. (4) Voids are produced by heating along the Au-intermetallic compound boundary.
From these results, the effects of organic contamination for Au-Al wire bonding are discussed.View full abstractDownload PDF (2248K) -
Noboru Yoshikawa, Haruhiko Aikawa, Atsushi Kikuchi1992 Volume 56 Issue 10 Pages 1132-1136
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA reactant gas mixture composed of TiCl4, H2 and N2 was introduced to the tubular reactor and TiN was deposited on the inner wall of the reactor under different conditions (temperature, total gas flow rate, PTiCl4, PH2/PN2 ratio). The growth rates of the films formed were obtained by measuring the thickness of the films.
At 1273 K and PN2/PH2=1, the growth rate of the film decreased as PTiCl4 increased in the range 1.52 kPa≤PTiCl4≤4.05 kPa.
At 1273 K and PTiCl4=2.43 kPa, the growth rate of the film had a maximum in the case of PN2/PH2=1.
The rate equations were obtained at 1273 K in the range 1.52 kPa≤PTiCl4≤4.05 kPa as follows:
R∝P−0.1TiCl4·PH20.5·PN2(PN2/PH2≤1),
R∝P−0.1TiCl4·PH2·PN20.5(PN2/PH2≥1)
The apparent activation energy of the growth rate of the film at PN2/PH2=1, PTiCl4=2.43 kPa was determined to be 230 kJ/mol (1173∼1273 K).View full abstractDownload PDF (631K) -
Zhongda Yu, Kusuhiro Mukai1992 Volume 56 Issue 10 Pages 1137-1144
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present study has been conducted to clarify the local corrosion of solid oxide at the slag surface where the dissolution of solid oxide into the slag results in the reduction of its surface tension through direct observation of the local corrosion in SiO2(s)-(FetO-SiO2) slags. The results obtained are as follows: (1) The major part of the local corrosion zone occurs in the meniscus region of the slags which is called “slag film”. (2) The film has two types of characteristic movement. One is a rotational movement around the specimen surface on the initial stage of the local corrosion of the rod specimen; Another is an up and down movement of the whole slag film all at once along the specimen surface on the developed stage of the local corrosion of the rod specimen, and on the whole stage of the corrosion of the prism specimen. (3) Linear rate of corrosion, dL/dt, at the most corroded portion in the local corrosion zone increases with increasing temperature and FetO content. dL/dt at the corner of the prism specimen is \sqrt2 times as large as that at the plane. In a word, the cross section of the prism specimen keeps a square during the whole stage of the corrosion. For the rod specimen. dL/dt decreases with increasing initial diameter of the specimen. (4) A mechanism of the local corrosion for the present slag system has been estimated qualitatively from the standpoints of the Marangoni effect of the slag film induced by the dissolution of the specimen into the slag, and the wetting between the specimen and slag.View full abstractDownload PDF (1266K) -
Sei Kimura, Ryokichi Shimpo, Yasushi Nakamura1992 Volume 56 Issue 10 Pages 1145-1151
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA ceramic superconductor, YBa2Cu3O6.5+x, decomposes to liquid and Y2BaCuO5 at about 1280 K in air. In this study, effects of the oxygen partial pressure (PO2) on the decomposition were examined by means of powder X-ray diffraction analysis, thermal gravimetry and differential thermal analysis.
The relation between PO2 and the temperature of decomposition was obtained by the analysis of X-ray diffraction for the samples equibrated at various temperatures in various oxygen partial pressures, and was expressed in the equation of ln(PO2/P°)=−113700/T+88.5[1218-1313 K. P°=101325 Pa]. The weight loss caused by the release of oxygen was also measured at the decomposition of YBa2Cu3O6.5+x under various oxygen partial pressures. The relation between x in YBa2Cu3O6.5+x and temperature when the decomposition occured was expressed as x=0.00353T−5.08[1218-1313 K]. The composition of the liquid formed by the decomposition was also determined.View full abstractDownload PDF (978K) -
Fumiyoshi Kirino, Noriyuki Ogihara, Norio Ohta1992 Volume 56 Issue 10 Pages 1152-1160
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe simple layer structure disk for magneto-optical recording was studied for applications of the erasable optical disk. Pt and Nb doped TbFeCo films had high corrosion resistance such as the dry corrosion, pitting corrosion, and wet corrosion. The recording film peels off from the PC substrate, as it was exposed in 60°C-95%RH for the simple sturucture disk to produce on the polycarbonate substrate (PC substrate). To increase the adhesive force, the TbFeCoPtNb film was protected from corrosions by the metal nitride layer such as TbFeCoPtNbN at the surface of the TbFeCoPtNb film. This nitride layer (5∼10 nm in thickness) was effective for increasing the corrosion resistance and bonding of the PC substrate. The carrier to noise ratio (C/N) was 43 dB at the recorded data at this disk. This disk has the high corrosion resistance such as dry corrosion, wet corrosion and pitting corrosion. The C/N was changed by the dry and wet corrosions, and the jitter width was changed by the pitting corrosion. These results show that the simple layer structure disk is suitable as the erasable optical disk because of its high reliability.View full abstractDownload PDF (1320K) -
Chengxiang Wu, Atsushi Nishikata, Tooru Tsuru, Atsushi Takei1992 Volume 56 Issue 10 Pages 1161-1167
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAC impedance technique has been applied to the evaluation of corrosion resistance of high temperature protective Aluminized coatings in Na2SO4-Li2SO4 melt at 973 K. The monitoring of corrosion behavior was conducted by the continuous measurement of impedance at 10−2 Hz. These data reveal that the substrate materials have a great effect on the corrosion resistance of Al coatings. Also, it is found that the corrosion resistance of Al coatings can be improved by preoxidation. The results from AC impedance measurements were well correlated with the results of SEM surface observation. On the basis of the obtained impedance characteristics, a simple model of equivalent circuit has been set up to explain the corrrosion process of Al coating. The AC impedance method is shown to be a useful tool for the evaluation of molten salt corrosion.View full abstractDownload PDF (2142K) -
Takao Hanawa, Osamu Okuno, Hitoshi Hamanaka1992 Volume 56 Issue 10 Pages 1168-1173
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe surfaces of Ti-Zr alloys before and after immersion in an electrolyte which contains inorganic ions found in the biological system were characterized using X-ray photoelectron spectroscopy (XPS), in order to know the changes in the surfaces of the system. Plates of Ti-25Zr, Ti-50Zr, Ti-60Zr, and Ti-75Zr alloys (in mass%) and metallic Ti and Zr were polished and immersed in the solution at 310 K for 3.6 ks (1 h), 86.4 ks (1 d), or 2.6 Ms (30 d) in sealed bottles. After immersion, the specimens were washed and analyzed using XPS. The XPS data revealed that the ratios of the relative concentrations of Ti to those of Zr in the surfaces were almost the same as those in the bulks. In the surface oxide layer, Ti and Zr were uniformly distributed along the depth direction. The thickness of the surface oxide of the alloys before immersion increased with increasing the Zr content in the alloys. The chemical state of Zr was stabler than that of Ti in the surface oxide layer. In surface layers of the alloys, mainly oxidation primary proceeded by the immersion and then hydroxidation occurred. Calcium phosphate was only formed on Ti-25Zr immersed for 2.6 Ms and metallic Ti whereas titanium phosphates and/or zirconium phosphates were formed under other conditions.View full abstractDownload PDF (814K) -
Yoshinobu Nakada, Toshimoto Koutsuka, Kazuhisa Mine, Hisaaki Suga1992 Volume 56 Issue 10 Pages 1174-1178
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe purposes of this study were to evaluate the influences of the primary ion beam current and the primary ion beam sweep area on the quantitative analyses of carbon and oxygen in silicon single crystals by secondary ion mass spectrometry (SIMS). The influences of them were examined in consideration of the slope of calibration curves and the form of craters. Five different (100) silicon single crystals, whose carbon and oxygen concentrations were determined by Fourier Transformation infrared spectrometry (FT-IR), were used as samples.
The best analytical conditions of carbon and oxygen obtained were 0.6 μA and 1.0 μA for the primary ion beam current and 200 μm×200 μm and 100 μm×100 μm for the primary ion beam sweep area, respectively. The high primary ion beam current density was suitable for the oxygen analysis, and the medium primary ion beam current density for the carbon analysis. The reason of the difference of suitable primary ion beam current density is explained with a difference of mechanism of adsorption of carbon-containing molecules and oxygen-containing molecules under the ion bombardment. Adsorption of carbon-containing molecules on the sample surface is enhanced under the ion bombardment, whereas that of oxygen-containing molecules is not enhanced. So, the high primary ion beam current density is not suitable for the carbon analysis since the background intensity is increased by adsorption of carbon-containing molecules.
At the best analytical condition of oxygen obtained, the sputtering rate was 15 nm/s and the form of crater after ion sputtering became like a corn. Therefore, the depth resolution was wrong and sensitivity is not compatible with depth resolution on SIMS analysis.View full abstractDownload PDF (764K) -
Takashi Kimura, Masatoshi Fukamachi, Akira Ohba1992 Volume 56 Issue 10 Pages 1179-1184
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to reveal the segregation of small amount of Ga in iron ores, a technique of computer image processing was applied to improve the resolution of concentration in EPMA X-ray images. In this technique, first, the net X-ray intensity was obtained by applying a back-ground correction on a pair of X-ray images observed with the wave-lengthes at the peak and the tail positions of the profile of characteristic Ga X-ray, respectively. Next, a computer image processing of the moving average with a large filter size was applied to improve the resolution of concentration in the X-ray images.
This technique was applied to reaveal the segregation of Ga in the region smaller than a few micron meters in the concentration range of 100∼250 ppm in the iron ore with the average concentration of Ga 54 ppm. The magnetite contained fine minerals of the order of a few micron meters and Ga was concentrated in these small minerals.View full abstractDownload PDF (1593K) -
Kiyoshi Ichikawa, Masakazu Achikita1992 Volume 56 Issue 10 Pages 1185-1191
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe electrical conductivity and the mechanical properties of dispersion-strengthened (DS) coppers produced by compocasting at a rotating speed of 25 s−1 with the addition of fine carbide particles in the range of 0.5 to 30 mass%WC, TaC, TiC, VC and NbC were experimentally analyzed. Homogeneous dispersion of carbide particles was observed in the microstructures of all the DS coppers containing more than 5 mass% carbide. If any carbide particle had the same size of 1 to 2 μm in the DS coppers, the Vickers hardness, Hv, was given by the following equation: Hv=53.4+3.5 V0.9P, where VP was the volume percentage of carbide particles. The ultimate tensile strength of carbide particles could be evaluated using the measured ultimate tensile strength value of copper, the fractions of area occupied by copper and carbide particles, and the measured ultimate tensile strength value of DS copper. The calculated ultimate tensile strength values of WC, TaC, TiC, VC and NbC particles were 961 MPa, 539 MPa, 568 MPa, 641 MPa and 755 MPa, respectively. Similarly, the electrical conductivity of carbide particles could be also evaluated. Their calculated electrical conductivity values were in the range of the published values of electrical conductivity of the carbides.View full abstractDownload PDF (1313K) -
Kohei Amano, Katsuhisa Sugimoto1992 Volume 56 Issue 10 Pages 1192-1199
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to obtain composite oxide films with corrosion resistances against both aqua regia and concentrated NaOH solutions, Ta2O5-ZrO2 films were formed on Pt and Si substrates by low pressure CVD techniques using tantalum pentamethoxide (Ta(OCH3)5), zirconium-tetra-isopropoxide (Zr(O-i-C3H7)4) and oxygen. The films obtained were composed of composite oxides of which the indepth composition was uniform. The changes in the corrosion resistance of the films were investigated as a function of film composition. The corrosion resistance of the films in aqua regia increased with increasing Ta(V) cation ratio but that in a 10.0 kmol·m−3 NaOH solution increased with increasing Zr(IV) cation ratio. The highest corrosion resistance aginst both aqua regia and 10.0 kmol·m−3 NaOH solutions was obtained at the Ta(V) cation ratios between 0.3 and 0.5. The films with such composition have fine and uniform structures.View full abstractDownload PDF (2261K) -
Seiji Miura, Yoshinao Mishima, Tomoo Suzuki1992 Volume 56 Issue 10 Pages 1200-1206
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe temperature, strain-rate and orientation dependences of strength are investigated in single crystalline Ni3(Al, 5.0Si), and the results are compared with those on Ni3(Al, 2.5Si) single crystals reported previously by the present authors. The magnitude of the anomalous positive temperature dependence of strength is found to increase with increasing Si additions and the value of activation energy to yield the mechanical anomaly is found to be in good accordance with that being predicted from the data for polycrystals. For an orientation near [\bar111], where the cube slip governs the plastic behaviour above the peak temperature, the temperature and strain-rate dependences of strength are found to differ considerably from what was found in Ni3(Al, 2.5Si). This is shown to be caused by the difference in the deviation from stoichiometry and not by the difference in Si content of the alloys. On the other hand, the steady-state deformation behaviour being governed by the octahedral viscous flow for the orientation near [001] resembles that in Ni3(Al, 2.5Si), where the stress exponent as well as the activation energy for the deformation is found to be nearly identical. The activation energy evaluated is of the same order as that for diffusion of Si in Ni3Al.View full abstractDownload PDF (1010K) -
Seiji Miura, Motoyuki Koike, Kung Wang, Yoshinao Mishima, Tomoo Suzuki1992 Volume 56 Issue 10 Pages 1207-1213
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to make a comparison of the plastic behaviour between Ni3Al and Ni3Ge, where Al is a 3B and Ge a 4B-subgroup element, effects of temperature, orientation and strain-rate on the temperature dependence of strength are investigated in Ni3Ge single crystals with 76 at%Ni. It is found that at 77 K there is an appreciable orientation dependence in compressive 0.2% flow stress. For orientation near [\bar111], the onset of cube slip is found to occur at as low as ambient temperature which is unusual for the L12 single crystals. The thermal component of critical resolved shear stress for the cube slip vanishes also at a much lower temperature and the athermal component is found to exhibit a slight negative temperature dependence arising from the temperature dependence of shear modulus. For orientation near [001] and at the temperatures above the peak, the characteristic yield drop and the following steady-state deformation are found as in other L12 intermetallic compounds. The activation energy for the steady-state deformation is found to be 277 kJ/mol which is reasonably in good agreement with the value for the diffusion of Ge in Ni3Ge.View full abstractDownload PDF (977K) -
Seiji Miura, Yoshinao Mishima, Tomoo Suzuki1992 Volume 56 Issue 10 Pages 1214-1220
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe temperature, orientation and strain-rate dependences of strength are investigated in single crystalline Ni3Al-4Cr (74 at%Ni-22 at%Al-4 at%Cr) in which Cr substitutes both Ni and Al sites. It is found that the solid solution hardening evaluated at 77 K by Cr addition is small and that the activation energy for the thermally activated cross slip yielding the mechanical anomaly becomes slightly larger by the addition. In the temperature range and for an orientation near [\bar111] where cube slip governs the plastic deformation, the athermal component of the critical resolved shear stress (CRSS) is evaluated to be as small as 40 MPa, whereas the thermal component at 0 K is estimated to be 2250 MPa being as large as the value reported for the Ni-rich Ni3Al single crystals. For an orientation near [001], where the octahedral viscous flow governs the plastic behaviour, the activation energy for the steady-state deformation is evaluated to be 317 kJ/mol which is in good agreement with the value for diffusion of Cr in Ni3Al. It is also found that the oxididation resistance of Ni3Al-4Cr is superior to Ni3(Al, 5.0Ti) but is inferior to Ni3(Al, 5.0Si). It is concluded, therefore, that the stoichiometry of Ni3Al-Cr cannot be made unequivocally.View full abstractDownload PDF (1143K) -
Masami Taguchi, Hiroaki Takahashi1992 Volume 56 Issue 10 Pages 1221-1227
Published: 1992
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSChromium nitride films were deposited on glass substrates by r. f. reactive ion plating, and the deposition rate, the structure and the corrosion resistance of the films were investigated. The deposition rate increased, but the nitrogen content of the nitride film tended to decrease with increasing the current of electron beam for evaporating chromium at a constant nitrogen pressure. X-ray diffraction showed that the film was a solid-solution of Cr and N (α-Cr) at the current of 100 mA, a mixture of Cr2N and CrN at 60 mA, and a single phase of CrN at 10∼50 mA. The decrease in current led to a transformation in the film structure; a structured film changed to a nearly amorphous, dense film with a smooth surface, and a great improvement in the corrosion resistance. The Cr and α-Cr film were rapidly corroded in 1 kmol·m−3 H2SO4 at 373 K, while the single phase of CrN hardly corroded. On the mixture of Cr2N and CrN, the Cr2N was selectively corroded and the amount of dissolved chromium was about two orders of magnitude larger than that for the single phase of CrN. The films deposited with low electron beam current were bent due to the difference in the thermal expansion between the film and the substrate, and some of them were peeled off during the corrosion test.View full abstractDownload PDF (1316K)
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