巻号一覧
52 巻, 2 号
選択された号の論文の17件中1～17を表示しています
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弘津 禎彦, 上原 雅史1988 年 52 巻 2 号 p. 129-138
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーHigh-resolution electron microscopy has been applied to microstructural observations of an amorphous Pd77.5Cu6Si16.5 alloy. In all the specimens prepared at different cooling rates, images of microcrystalline domains were clearly observed and thereby the formation of the medium range order (MRO) in this alloy was proved. The average size of these MRO domains was found to vary from 3.0 to 1.5 nm depending on the cooling rate and on the melt temperature on cooling. From the geometries of the crossed-lattice images and also from the microarea electron diffraction, the structure of the MRO domains was identified as that of palladium with the face-centered cubic structure.抄録全体を表示PDF形式でダウンロード (4173K) -
古屋 泰文, 島田 平八, 松本 実, 本間 敏夫1988 年 52 巻 2 号 p. 139-143
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーRecently, the robot actuator worked by the driving recovery-force in thermoelastic martensitic transformation of shape memory alloys (SMA) is under development. In general, such a SMA actuator necessitates a number of cyclic repeated motions, so that the investigation of the gradual decrease of recovery force with repeated motion cycles as well as the prevention of such a degradation of shape memory effect (SME) are very important for the actual use as a robot actuator. However, such research and discussions about the degradation of SME are very few up to the present. Therefore, in the present study, the most basic, single axial SMA actuator of Ni-Ti wire is made, and the cyclic motion (i.e. fatigue) test by the alternative, heating up and cooling down of SMA Ni-Ti wire is performed. Heating up of wire is done by a direct current method, and cooling down by fan in air. The characteristics on the cyclic motion and its degradation of SME is discussed. As a result, the degradation in SME can be devided in two factors; the cyclic deformation by martensitic-trasformation and the gradual elongation of Ni-Ti wire. From the investigation in the changes of these two factors with repeated motion cycles, it is found that the latter factor contributes to the degradation to a much greater extent than the former under the present fatigue test condition of Ti-Ni wire. The efficiency of training before the use of SMA material is confirmed as one of the useful measures to prevent the degradation of SME in engineering applications.抄録全体を表示PDF形式でダウンロード (572K) -
池田 勝彦, 小松 伸也, 杉本 隆史, 亀井 清1988 年 52 巻 2 号 p. 144-149
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe composition and temperature dependence of resistivity ρ was studied for Ti-2∼25 mass%Mo alloys quenched from 1173 K. The retained β phase after water quenching from 1173 K was observed in the alloys containing more than 9 mass%Mo. The anormal, so-called “negative”, temperature dependence (NTD), characterized by a larger ρ value at liquid nitrogen temperature than that at room temperature, appeared in the composition range between 10 and 23 mass%Mo. The observed anormal NTD was completely reversible and could be classified into three types at elevating measurement temperature by the behavior of the temperature coefficient of ρ, δρ⁄δT:
(i) In the lower NTD composition range (10 and 12 mass%Mo), δρ⁄δT changed from positive to negative after passing through a maximum in ρ.
(ii) δρ⁄δT was always negative over the whole temperature range of measurement in the medium part of the NTD composition range (12-15 mass%Mo) and
(iii) In the higher NTD composition range (20 and 23 mass%Mo), δρ⁄δT changed from negative to positive after passing through a minimum in ρ.
Because of the complete reversibility, the NTD was related to a diffusionless phase transformation, e.g. athermal ω formation, without any hystereses and not to aging phenomena with diffusion. The NTD with a maximum and minimum in ρ can be explained qualitatively from summation of a normal temperature dependence of stable β phase and an increase in ρ due to the formation of the athermal ω phase with decreasing temperature.抄録全体を表示PDF形式でダウンロード (882K) -
羽坂 雅之, 万 永, 内山 休男, 古賀 秀人1988 年 52 巻 2 号 p. 150-156
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe phase relationship and the phase transformation in the rare earth-cobalt (R-Co) alloys were investigated by using a pair approximation. The structures of the alloys investigated were RCo5 (CaCu5 type), R2Co17 (Th2Zn17 type), and R2Co7 (Gd2Co7 type), It was proposed that RCo5 and R2Co17 phases coexist stably with each other because the value of ordering energy depends on the distance between atoms. The phase separation of RCo5→RCo5+R2Co17 in Sm-Co and Gd-Co alloys follows spinodally if ordering of the Th2Zn17 type occurs. The composition of the eutectoid transformation RCo5→R2Co7+R2Co17 shifts to the Co-rich side with decreasing ordering temperature and increasing eutectoid temperature.抄録全体を表示PDF形式でダウンロード (1012K) -
落合 鍾一, 上野 学1988 年 52 巻 2 号 p. 157-162
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーMartensitic transformation start (Ms) temperatures have been measured in binary NiAl sintered alloys (36-38 at%Al) using an electrical resistivity method. The composition dependence of the Ms temperature has been investigated by a statistical approach employing the Bragg-Williams approximation. The results obtained are as follows: (1) In these alloys, the linear relationship between Ms tempearture and aluminum content, having a slope of about-160 K/at%Al, was observed. The Ms tempertaure is about 30 K below the corresponding Af temperature. (2) There are no differences in the composition dependence of the Ms temperature between the sintered and cast alloys. (3) The Composition dependence of the Ms temperature is found to have a good correlation with that of To. (4) The interaction parameter VNiAl′ between Ni and Al atoms in the martensite phase could be estimated at about −12.7 kJ/mol. (5) The composition dependence of the Ms temperature is closely related to the interaction parameters in the parent and martensite phases and the temperature dependence of the difference in the Gibbs free energy of constituent elements between the Al (fcc) and the A2 (bcc) crystal structure.抄録全体を表示PDF形式でダウンロード (777K) -
湯浅 栄二, 師岡 利政, 葉山 房夫1988 年 52 巻 2 号 p. 163-170
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーGraphite-dispersed Al-Si alloys were prepared by the combined process of sintering and hot extrusion (sintering/hot-extruding process). The wear characteristics of the products were examined at various sliding speeds and compared with those of sand castings of Al-Si alloys (casting process) and of the graphite-dispersed Al-Si alloys prepared by re-melting and freezing in a quartz tube after extruding the mixture of aluminum, silicon and graphite powders (re-melting process). Effects of the matrix structure and graphite particles on the wear characteristics of these graphite-dispersed alloys were discussed. In the sintering/hot-extruding process the values of wear rates of these alloys with the matrix phase of fine eutectic structure were extremely small in the range of low sliding speeds. In all the alloys the wear rates increased with increasing sliding speed and then attained a peak value. The increment of the wear rate in this range of sliding speeds decreased with increasing silicon content in the matrix phase and with increasing volume fraction of the graphite particles. With a further increase of the sliding speed, the wear rate decreased and attained a small value. However, the contents of silicon and graphite in these alloys exerted a negligible effect on the decrement of the wear rate. When the alloy having a soft matrix phase as with a low silicon content was rubbed in the range of high sliding speeds, the wear rate showed a low value, but it was remarkably increased by adhesion to a counterface as the sliding speed increased.抄録全体を表示PDF形式でダウンロード (2593K) -
東田 賢二, 高村 仁一, 成田 舒孝, 松平 恒昭, 後藤 勝彦, Suzuki Francisca M.1988 年 52 巻 2 号 p. 171-179
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーCorroborative evidence for the origin of generation of secondary slip at stage II in the stress-strain curve has been obtained by detailed analyses with the etch-pit technique in copper crystals. It is shown that a sudden occurrence of secondary slip at stage II is directly related to the formation of deformation bands, particularly to the building-up of kink-band walls that is, as reported previously, the trigger for the transition from stage I to II. Among secondary slip systems actually observed in the kink-band wall region, the operation of the cross slip system (S42) is of particular interest because of its Schmid factor being zero. This strongly suggests that the sudden generation of secondary slip is caused by the internal stress induced by primary main slip (S11) dislocations piled-up against the kink-band wall. From the calculation based on a pile-up model, it is understood that primary coplanar slip S13 and secondary systems such as critical main slip S31, conjugate main slip S21, critical coplanar slip S23 and cross slip S42 are subject to fairly large internal stresses due to the pile-up of S11 dislocations. Especially, the operation of S21 and S33 is important because of their interaction with S11 which leads to the formation of Lomer sessiles.抄録全体を表示PDF形式でダウンロード (2249K) -
中島 英治, 岩崎 浩司, 後藤 正治, 吉永 日出男1988 年 52 巻 2 号 p. 180-188
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーIn order to clarify the combined effect of solution and dispersion hardenings at high temperature, the internal stress, the effective stress and dislocation density in Al-3 mol%Mg-1 mol%Mn alloy have been measured and compared with those in Al-3 mol%Mg alloy. The measurement has been carried out by applying the stress-relaxation technique to the steady-state tensile deformation at temperatures from 573 to 723 K and at strain rates from 3×10−5 s−1 to 3×10−3 s−1.
It is found that the additive rule of hardenings by solute Mg atoms and dispersed Al6Mn particles holds in the low Z region, but the effect of dispersion hardening decreases with the increase of Z, which is the Zener-Hollomon parameter. This behavior is explained by the relative value of the inter-dislocation spacing to the inter-dispersoid spacing. In the low Z region where the dislocation spacing is larger than the dispersoid spacing, nearly all dislocations undergo the resistance of dispersoids, and the additive rule holds. In the high Z region, however, the dislocation spacing becomes smaller than the dispersoid spacing, and the part of dislocations not directly contacting with the dispersoids increases as Z increases, resulting in the decrease of the effect of dispersion hardening.抄録全体を表示PDF形式でダウンロード (1590K) -
原 信義, 杉本 克久1988 年 52 巻 2 号 p. 189-198
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーPhotocurrent iph and photopotential Vph vs. time t curves of thin γ-Fe2O3 films (<10 nm) deposited on Pt by MO-CVD technique were measured under intermittent illumination of white Xe arc light at various electrode potentials in neutral Na2SO4 solutions. Bode diagrams of the same film-solution systems were also measured over a wide frequency range in darkness and under continuous illumination.
A fast photocurrent transient was observed in the iph vs. t curve immediately after the illumination; the photocurrent increased to a maximum value iph,t within 10 ms, and then decreased down to a stationary value iph,s. The iph,t, which was observed above 0.3 V, showed the maximum of ca. 1.5 A·m−2 at 1.0 V. The increase in iph,s occurred when the potential exceeded 0.8 V. Time-dependent changes in the transient photocurrent were very similar to those in the differentiated photopotential, showing that the intermittent illumination causes capacitance charging and discharging of the film. The Bode diagrams showed the existence of surface-state with a large relaxation time (2 ms-1 s) at the film-solution interface and the increase in the capacitance of the surface-state with increasing potential and with illumination. From these results, it was thought that both the transient photocurrent and the photopotential arise from the displacement of charges in the space-charge layer of the film, which is attributed to the trapping and accumulation of photo-generated holes in the surface-state.抄録全体を表示PDF形式でダウンロード (1534K) -
三重野 正寛, 吉田 豊信, 明石 和夫1988 年 52 巻 2 号 p. 199-203
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーBoron nitride films were deposited on silicon substrates by reactive sputtering of h-BN target in H2/N2 or He/N2 discharge at the substrate temperature range of 298-1073 K. Prepared films were investigated by means of infrared spectroscopy (IR), Auger electron spectroscopy (AES), reflection high energy electron diffraction (RHEED) and X-ray diffraction (XRD), and plasma was monitored by optical emission spectroscopy.
The following results were obtained: N/B ratio in the films increased with increasing partial pressure of H2 in H2/N2 discharge, but such an effect did not occur in the He/N2 discharge because of penning ionization. High-pressure phases appeared at the substrate temperature above 873 K, and the phase content increased in consequence of increasing the substrate temperature, rf power, working pressure, partial pressure of H2 and substrate-target distance, especially the substrate temperature and the rf power. These conditions were considered to promote either to activate the surface of growing film or to decrease the deposition rate.抄録全体を表示PDF形式でダウンロード (678K) -
上埜 修司, 早稲田 嘉夫1988 年 52 巻 2 号 p. 204-210
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーA theoretical equation for the activity coefficient of the solute at infinite dilution in metallic solutions has been described by the pseudopotential formalism coupled with the hard sphere model. The approximate equation for the pseudopotential term has also been proposed in terms of the molar heat of solution at infinite dilution, in order to allow simple estimation of the activity coefficient in various metallic solutions.
It was found from the calculation of the excess entropy of the solute at infinite dilution that the electron gas term is generally less than 5% of the hard sphere term and therefore the contribution from the electron gas appears to play an insignificant role in determining the sign and absolute values of the excess entropy or the activity coefficient of the solute at inifinite dilution. The present theory has been applied to 33 cases in non-ferrous alloys such as Al-base, Pb-base and Cu-base solutions and 15 cases in Fe-base solutions. The calculated values of the activity coefficient of the solute at infinite dilution were found to be in reasonable agreement with the experimental data in both non-ferrous and ferrous solutions. It should be, however, noticed that the present results do not explicitly include the entropy effect of 3d electrons which is likely singnificant in ferrous solutions.抄録全体を表示PDF形式でダウンロード (959K) -
八尾 伸也, 濱 信郎, 赤田 明彦, 幸塚 善作1988 年 52 巻 2 号 p. 211-216
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe activity coefficients of oxygen, γ0, in liquid Ag-Bi, Ag-Cu and Ag-Bi-Cu alloys at 1373 K have been measured utilizing a modified coulometric titration method with the electrochemical cell: O in liquid alloy/ZrO2(+CaO)/air, Pt. The composition dependence of γ0 in liquid Ag-Bi-Cu alloys at 1373 K was determined over the entire composition range by combining the present results with previous ones in liquid Bi-Cu alloys. The iso-γ0 lines exhibit convex curves toward Ag, and the lnγ0, values, plotted along the composition lines, i.e., Ag-Bi0.5Cu0.5, Ag0.85Bi0.15-Cu0.85Bi0.15, Ag0.85Cu0.15-Bi0.85Cu0.15, lie on downwardly convex curves. The solution model of Kapoor, which was the extension of the Wagner model to the oxygen in ternary alloys, gives a satisfactory representation of the data.抄録全体を表示PDF形式でダウンロード (674K) -
能登谷 久公, 米谷 茂, 高辻 雄三1988 年 52 巻 2 号 p. 217-222
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe effect of the residual grinding stress on the volume fraction of martensite in the ground surface layer of austenite stainless steel was investigated. When the austenite stainless steel is worked, a part of austenite transforms to martensite, and the volume fraction of martensite depends on the degree of working. From the experimental studies, it should be concluded that the structures in the ground layer retransforms to austenite by the heat of grinding, and the top of the surface layer changes in specific volume. The increasing austenite in the top of the surface layer increases with the residual stress of the ground layer.抄録全体を表示PDF形式でダウンロード (695K) -
大森 正信, 賀屋 章, 原田 泰典, 吉田 総仁, 伊藤 操1988 年 52 巻 2 号 p. 223-228
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーTensile properties of sintered powder chromium (99.9 mass% purity) produced by a cold isostatic press (CIP) and a hot isostatic press (HIP) were preliminarily examined to find conditions favorable to the plastic working of the sintered chromium. Specimens A and B1 taken from a sintered ingot A and a half of an ingot B, respectively, were annealed at 1823 K higher than 1473 K encountered in the present HIP. Specimen B2 from the remainder of the ingot B was not heat treated.
Transition from ductile to brittle fracture occurred very sharply, i.e., in a small range of temperature, and at the higher temperature in a testing at the higher speed of deformation. Ductile-to-brittle transition temperature of the specimen B1 was lower than that of the specimen B2 suggesting that the annealing at 1823 K is effective in lowering the transition temperature. Small plastic tensile prestrain given to a specimen at a temperature slightly beyond its transition temperature considerably reduced the brittleness of the specimen. This prestraining effect is supposed to come from free dislocations generated in the prestrained specimen. At temperatures between 700 K to 1023 K, flow stress was never changed even when the strain rate was increased from 1.7×10−4 s−1 to 1.7×10−1 s−1, and the decrease of the stress with increasing temperature was small.抄録全体を表示PDF形式でダウンロード (904K) -
矢野 哲夫, 柳沢 平, 大森 正信1988 年 52 巻 2 号 p. 229-235
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe stress distribution in a fiber reinforced composite induced by cooling and heating and its change by subsequent tensile/compressive loading are calculated. The results are discussed in the light of various experimental data for the Al-Al3Ni eutectic composite.
The method used for the analysis of stress and strain distribution is based on Brown’s one, into which the effect of thermal is incorporated. The constitutive equation for the Al matrix is assumed to be two-fold. In the high temperature range (above 523 K), an equation which is derived from the data for steady state deformation of pure aluminum with Orowan’s stress taken as the threshold stress is applied. In the low temperature range, a power law equation which is obtained from tensile tests of pure aluminum is assumed.
It is shown that the present calculations are useful for the understanding of the thermomechanical behavior of the Al-Al3Ni eutectic composites with different interfiber spacings.抄録全体を表示PDF形式でダウンロード (939K) -
大島 聡範, 林 忠夫, 高橋 忠義1988 年 52 巻 2 号 p. 236-242
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーApplicability of Manson’s rule to low cycle fatigue of cast steel containing small casting defects is examined taking account of the dependance of fatigue life upon tensile fracture strain.
Results are summarized as follows.
(1) Manson’s rule is applicable to the low cycle fatique of the defective cast steel, on the ground of the correlation between the increase in defectivity and the reduction in tensile fracture strain.
(2) Low cycle fatigue lives of the defective cast steels decrease with the increase of the total strain intensity factor range of initial defects.
(3) Low cycle fatigue life prediction of the defective cast steel using Paris’ rule based on the initial defect size corresponds well to the prediction using Manson’s rule based on defectivity.抄録全体を表示PDF形式でダウンロード (1193K) -
盛田 芳雄, 梅田 高照, 木村 康夫1988 年 52 巻 2 号 p. 243-250
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーSm-Co-Cu-Fe-Zr phase diagram near compositions of magnet alloys, that is, Sm-Co-7.0 at%Cu-22.0 at%Fe-(0, 1.4, 2.0 and 3.0 at%)Zr sections of the phase diagram were determined in the Sm content range from 6 to 16 at% above 1073 K, and effects of Zr on the phase transformation and magnetic properties of the magnet alloys were investigated. The results are summarized as follows:
(1) Addition of Zr by 1.4 or 2.0 at% expands the Sm solubility in 2/17 phase towards both richer and poorer side, and changes the crystal structure of 2/17 phase to TbCu7 and/or Th2Ni17 type structure(s) at high temperature. Addition of Zr by 3.0 at% expands (2/17+2/7) phase region, in which 2/17 phase has the TbCu7 and/or Th2Ni17 type structure(s).
(2) Sm(Co, Cu, Fe, Zr)z alloys possess high coercivity, when homogenized in 2/17 single phase with TbCu7 (Zr 1.4 and 2.0 at%) at high temperature and decomposed into 2/17 phase with Th2Zn17 type structure and 1/5 phase with CaCu5 type structure by aging treatment. The alloys which have this phase transformation shift the Sm content towards poorer Sm as the Zr content increased, and possess high coercivity in the above-mentioned Sm and Zr content range.抄録全体を表示PDF形式でダウンロード (1200K)
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