巻号一覧
50 巻, 12 号
選択された号の論文の14件中1～14を表示しています
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劉 世程, 濱口 由和, 桑野 寿1986 年 50 巻 12 号 p. 1023-1031
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーStable ranges concerning composition and temperature have experimentally been determined for the intermetallic compounds in the ternary Fe-Cr-Mo system. The existence of stable and intermediate R-phases in the ternary alloy is confirmed and the relation with that in the Fe-Mo binary alloy is experimentally established. The χ-phase does not exist above 1473 K (1200°C). The isothermal sections of the equilibrium phase diagram in the Fe-Cr-Mo ternary system at 1523 K (1250°C) and 1123 K (850°C), which are different in part from those shown in the literature, are proposed.抄録全体を表示PDF形式でダウンロード (1805K) -
湯浅 栄二, 師岡 利政, 葉山 房夫1986 年 50 巻 12 号 p. 1032-1040
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーGraphite-dispersed alloys with the Al-Si matrix phase consisting of various amounts and sizes of silicon particles were prepared by the powder extrusion. Effects of the dispersion of silicon and graphite particles on wear characteristic of the alloy were investigated at various sliding speeds. In the graphite-dispersed Al-Si(C) alloy with the matrix phase consisting of coarse silicon particles, the wear rate has a small value in the range of low sliding speed, but it is remarkably increased at high sliding speed. The increase of the wear rate is caused by plastic deformation of the aluminum phase and its breaking-away at silicon or graphite particles. In the case of the graphite-disparesed Al-Si(F) alloys with the matrix phase consisting of fine silicon particles, the sliding speed which causes a small wear rate is higher than that of the alloy with the matrix phase consisting of Al-Si(C) alloy. The wear rate increases with increasing sliding speed, but it decreased with the formation of hard layer containing aluminum oxide and fine silicon particles, accompanied by the lubricating effect of the graphite particles. This tendency becomes remarkable with increasing silicon and graphite contents. When the sliding surface with an angle θ=90° to the extrusion direction was rubbed, the increase of wear rate with the sliding speed is higher than that in the case of θ=0°. In the graphite-dispersed alloy with the matrix phase prepared from Al-12 wt%Si alloyed powder, the wear rate attains a maximum at a certain sliding speed, then decreases and reaches a minimum with increasing sliding speed. At higher sliding speed, the wear rate again increases rapidly.抄録全体を表示PDF形式でダウンロード (2854K) -
野末 章, 野瀬 哲郎, 大久保 忠恒1986 年 50 巻 12 号 p. 1041-1048
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe purposes of the present study are to identify the transition of fracture morphology and the mechanism of microstructurally sensitive cracking in 18%Ni maraging steel by systematically changing microstructure size and cyclic plastic zone size ω′. It has been widely known that the steel definitely consists of lath martensite, block, packet and prior austenite grain boundaries. Displacement controlled stress intensity factor range ΔK decrease tests were carried out with two kinds of stress ratios, 0.1 and 0.9, between ΔK=20 MPa·m1⁄2 and the threshold stress intensity factor range ΔKth. The lath martensite boundary cracking, the dominant fracture in the vicinity of the ΔKth value, is related to the ratio of the ω′ value to the lath martensite boundary size. Hence the three-dimensional morphology and the size of the lath martensite were identified by the three procedures: The morphology of the lath martensite boundary cracking was clarified. The lath martensite boundary lines were analyzed on cleavage cracks nearly parallel to the main crack. The distribution of the lath martensite size observed with a transmission electron microscope was evaluated. Consequently, the lath martensite boundary cracking was found to occur most frequently when the ω′ value was nearly equal to the lath martensite size.抄録全体を表示PDF形式でダウンロード (2698K) -
小野 陽, 佐藤 敦, 太田 裕之1986 年 50 巻 12 号 p. 1049-1055
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe scheme recently proposed by the authours on the basis of the Taylor model to deal with the deformation of polycrystals caused by the stress induced martensitic transformation (SIM) has been further extended to describe the recovery stress associated with the reverse transformation upon unloading. According to this scheme, the “modified” Taylor factor, M′ has been calculated as a function of grain orientation for the cases of tension and compression deformation in the shape memory alloys such as CuZnAl, CuAlNi and TiNi. The results demonstrated the difference in the plastic anisotropy for SIM of grains under the polycrystalline constraint from that of isolated crystalites. The strain hardening due to the internal stresses caused by the grain orientation dependence of volume change has been shown to be insignificant in these alloys. General discussion has been given to the yield stress, recovery stress, pseudoelastic hysteresis, recovery strain, ductility, and strain hardening of the shape memory alloys, in relation to the magnitude and orientation dependence of M′.抄録全体を表示PDF形式でダウンロード (1028K) -
川崎 亮, 渡辺 龍三, 島田 平八, 鈴木 英夫1986 年 50 巻 12 号 p. 1056-1060
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe strain distribution across jointed interface of metals and ceramics has been studied by speckle photography, by which a small strain of the order of 10−4 mm/mm with a gauge length less than 0.5 mm can be detected. Samples of molybdenum/silicon nitride and steel/copper/silicon nitride joints were tested under static compression at room temperature and thermal free-expansion heating up to about 573 K in air. The finite element calculation (FEM) was also made for thermal deformation. As a result, the applicability of speckle photography to determination of strain distribution across jointed interface of metals and ceramics was confirmed, and the results of the thermal strain measurement by speckle photography coincided well with those of thermal deformation analysis by FEM in the region of this study.抄録全体を表示PDF形式でダウンロード (1103K) -
陳 効列, 中佐 啓治郎, 武井 英雄1986 年 50 巻 12 号 p. 1061-1067
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーDelayed failure tests in air were carried out on the Ni-Cr-Mo steel specimens which were hydrogen pre-charged after quenching from 1123 K and tempering at 637 K, in order to investigate the effect of the crack propagation rate da⁄dt (which expressed the concentration of hydrogen inside the specimen) on the stress intensity factor at crack branching KIB and the crack branching angle. The results were compared with those of the specimens no hydrogen pre-charged and tested in water.
For the specimens pre-charged and tested in air, the crack branching occurred when the crack propagation rate da⁄dt was higher than 20×10−6 m/s and KIB decreased with increase in da⁄dt, while when da⁄dt was lower than 20×10−6 m/s, the unstable crack propagation occurred without crack branching. The branching angle of the pre-charged specimen tested in air was smaller than that of the no pre-charged specimen tested in water. These results can be explained both by a criterion which was introduced by a combination of hydrostatic tensile stress with hydrogen concentration at crack tip and by the difference in hydrogen diffusion path between the no pre-charged specimen tested in water and the pre-charged specimen tested in air.抄録全体を表示PDF形式でダウンロード (1147K) -
杉野 重明, 萩原 久人1986 年 50 巻 12 号 p. 1068-1074
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe activities of Zn in liquid Cu-Zn-X (X=Al, Ni) ternary alloys have been measured by the use of isopiestic method at temperatures 1423 K and 1373 K and in the composition range, NZn<0.09 and NX≤0.08. From the activity data the first and second order interaction parameters between Zn and X in molten Cu have been determined. The activity of Zn in Cu-Zn binary liquid alloys is increased by the addition of a small amount of Al and decreased by Ni. The activity coefficients of Zn in Cu-Zn-X ternary liquid alloys are well expressed by a quadratic relation,
lnγZn=lnγZn°+εZnZnNZn+εZnXNX+ρZnZnNZn2+ρZnXNX2+ρZnZnXNZnNX, in the composition range, NZn+NX≤0.10.
It has been demonstrated that the quadratic formalism proposed by Darken is valid for Cu-Zn-Al ternary liquid alloys in the composition range, NZn≤0.08 and NAl≤0.06.抄録全体を表示PDF形式でダウンロード (926K) -
大野 湶, 大古殿 秀穂, 春山 志郎1986 年 50 巻 12 号 p. 1075-1080
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーNickel-phosphorous alloys 10−100×10−6 m in thickness were produced by pulse plating. X-ray intensities diffracted from the deposits were progressively lowered with decreasing duty cycle of pulse and faded away for the deposit prepared with the duty cycle of 0.2 at the average current density of 2×102 A/m2. The Tafel slope and exchange current for hydrogen evolution of the deposited Ni-P alloys in a sulfuric acid solution were 0.060 V and 10−7 A/m2, respectively, whereas those of Ni were 0.12 V and 1×10−3 A/m2, respectively. Anodic polarization curves of the Ni-P alloys did not exhibit any passivity and were less sensitive to the pH value of the solution. The Ni-P alloy pulse-plated at an optimum condition is highly corrosion resistant in contrast to those produced by d-c plating.抄録全体を表示PDF形式でダウンロード (789K) -
植田 幸富, 西 隆之, 大石 敏雄, 小野 勝敏1986 年 50 巻 12 号 p. 1081-1088
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe thermodynamic properties of the liquid Ti-Co alloys have been determined over the entire composition range at 1873 and 1973 K. A Y2O3 Knudsen cell-mass spectrometric technique was used to carry out the measurements of the ionic intensity ratios for the alloy components. The thermodynamic activities show negative deviations from Raoult’s law. The activity coefficients at infinite dilution are γTi°=0.011 and γCo°=0.014 at 1873 K and γTi°=0.021 and γCo°=0.028 at 1973 K. The minimum values of the molar free energies of mixing ΔGM are, respectively, −32.1 kJ·mol−1 at 1873 K and −30.9 kJ·mol−1 at 1973 K (NCo=0.49). The molar enthalpies of mixing ΔHM and the molar entropies of mixing ΔSM are negative. The minimum value of ΔHM is −50.5 kJ·mol−1 (NCo=0.48) and the minimum value of ΔSM is −9.9 J·mol−1K−1 (NCo=0.48). The partial molar enthalpies of mixing Δ\barHTi and Δ\barHCo at infinite dilution are −152.2 kJ·mol−1 and −195.7 kJ·mol−1, respectively. The oxygen concentrations in the alloys were determined by analysis, and the effect of dissolved oxygen on the activity of the alloy and the selection of oxide crucible material for the alloy have been discussed.抄録全体を表示PDF形式でダウンロード (1006K) -
林 宏爾, 木原 宏1986 年 50 巻 12 号 p. 1089-1094
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe densification of compacts from Fe and Cu ultrafine powders (average particle sizes, 0.02 and 0.05 μm, respectively; oxygen contents, 15 and 6 mass%, respectively) and the average grain size in the sintered compact were investigated in relation to the relative density (Dg) of the green compact, heating-rate (dT⁄dt) and sintering temperature.
The sintered compact with full density and almost free from oxygen or oxide was obtained by sintering at 973-1073 K for each powder, when the sufficient reduction and also degasification were made to take place by decreasing both Dg and dT⁄dt to values considerably smaller than those usually set for normal coarse powders. In the case of large Dg and/or dT⁄dt, the Fe and Fe-50%Cu sintered compacts contained a large amount of remaining oxygen or oxides, although they were fully dense; the Cu compact was not fully dense, although it was free from oxygen. The reason for the difference was able to be explained from the viewpoint of PH2O⁄PH2 equilibrium pressure ratio in the reduction of the oxide by hydrogen. The average grain sizes in the fully dense and oxygen free sintered compacts were as small as 0.3-1.5 μm, although they were considerably larger than those of starting powders.抄録全体を表示PDF形式でダウンロード (1592K) -
花立 有功, 藤田 直也, 宮城 政和1986 年 50 巻 12 号 p. 1095-1100
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーSheets of a Cu-27.6Zn-3.8Al(mass%) alloy were quenched from a temperature in the β-phase range to 273 K and bent at 293 K. The sheets were then heated up to a temperature between 823 K and 1123 K and cooled down to room temperature.
A distinct shape change, winding on cooling and unwinding on heating, was observed at high temperature during the thermal cycle, when the treating temperature did not exceed 1023 K. The higher the maximum temperature, the larger the amount of shape change. The total amount of winding on cooling was found to be larger than that of unwinding on heating, and these amounts were unchanged on repeating thermal cycles. Accordingly, the sheet was successively wound as the number of cycles increased.
The shape change was found not to be affected by the external force, and so this phenomenon would be applied to production of RSM tools which work well even at high temperature.抄録全体を表示PDF形式でダウンロード (1617K) -
吉川 昇, 須藤 一1986 年 50 巻 12 号 p. 1101-1108
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーAlthough the properties of Y2O3-ZrO2 alloys have been extensively investigated for high strength ceramics, solid electrolyte and so on, the phase diagram of this alloy system in the temperature range over 1600°C (1873 K) has not been determined experimentally. In the present paper, the phase diagram of yttria partially stabilized zirconia (Y-PSZ) is proposed. The shapes of cubic-tetragonal (c-t) phase boundaries are like those in the diagrams of Co-Cu and several iron-base binary alloy systems in which Curie-point lines intersect miscibility gaps. The reason can be explained in the considerations that the c-t transition for pure ZrO2 is para-ferroelastic type and that the lattice parameter of t-ZrO2 changes with Y2O3 content continuously to that of c-ZrO2.
Then the formation mechanisms of complex microstructures of Y-PSZ, for examples, {100} type ferro-elastic domain, spinodally decomposed {111} type modulated structure, lath- or lenticular-tetragonal martensite and herring-bone structure, are discussed by using presumed free energy-composition curves.抄録全体を表示PDF形式でダウンロード (3631K) -
長谷川 英雄1986 年 50 巻 12 号 p. 1109-1115
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーThe Y2O3 doped PSZ and FSZ sintered ceramics were mechanically polished with SiC abrasive paper. The crystal structure of the abraded surface layer was examined by X-ray diffraction, and the flexural strength and the fracture toughness of PSZ subjected to polishing were measured, in order to clarify the influence of the surface modification on the structure and the mechanical properties of zirconia.
\ oindentThe results are summarized as follows:
(1) In the abraded surface layer, the cubic matrix phase (C-phase) was found to transform readily to rhombohedral phase (R-phase) having a distorted fluorite structure with respect to the specific [111] direction (α′=89.5°). This structure was approximately similar to the rhombohedral phase (α′=89.8°) induced by ion implantation.
(2) The C→R phase transformation is thought to be induced by a stress introduced by polishing. With increasing the roughness of the abrasive paper, the R-phase was formed more remarkably in PSZ than in FSZ. This can be explained by assuming that in FSZ, the stress imposed by the polishing is easy to relax by causing microcracks.
(3) By pulverizing and annealing, the R-phase disappeared to transform reversely to the original C-phase through stress relaxation. This suggests that the R-phase is metastable and exists only in the surface layer under stress.
(4) By forming the R-phase in the surface of PSZ, the flexural strength was found to increase by over 20% and the apparent fracture toughness by two to three times. The increases of the mechanical properties are thought to be caused by the surface compressive stress developed through the volume expansion associated with the C→R phase transformation.抄録全体を表示PDF形式でダウンロード (1533K) -
1986 年 50 巻 12 号 p. 1116
発行日: 1986年
公開日: 2008/04/04
ジャーナル フリーPDFを参照． （誤）932頁，Fig. 10の横軸の説明が印刷されておりませんでしたので，次の図とさしかえます． （正）932頁，Fig. 10の横軸の説明が印刷されておりませんでしたので，次の図とさしかえます．抄録全体を表示PDF形式でダウンロード (28K)
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