巻号一覧
35 巻, 8 号
選択された号の論文の15件中1～15を表示しています
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2粒子の接近について八木 秀次, 森 勇蔵, 紺田 功, 井出 敞1988 年 35 巻 8 号 p. 719-724
発行日: 1988/11/25
公開日: 2009/12/04
ジャーナル フリーThe amount of interpenetration of the two-particle system was studied analytically and experimentally. Using the models of neck growth in various sintering mechanisms, the geometrical relationship between the neck radius and the amount of interpenetration was derived. In the consideration of the atomic flow the following three shrinkage mechanisms were assumed: variable-radius-interpenetration mechanism, constantradius-interpenetration mechanism and deformation-interpenetration mechanism. The amount of interpenetration became larger in the above order in the same neck radius.
In the experiment, the amount of interpenetration in sintering was measured in two particles system using SEM. After the corrections, the amount of shrinkage in the experiment was distributed between the variable-radius-interpenetration and constant-radius-interpenetration in the calculated result.抄録全体を表示PDF形式でダウンロード (1451K) -
横田 勝, 高瀬 朗, 永井 宏, 庄司 啓一郎1988 年 35 巻 8 号 p. 725-730
発行日: 1988/11/25
公開日: 2009/12/04
ジャーナル フリーAs a preliminary experiment, influence of oxygen in atmosphere on the wettability of Pb to Fe plates was investigated. At constant oxygen partial pressure in atmosphere, wettability and infiltration behavior between Pb or its alloys and Fe plates or Fe green compacts were also examined. Results obtained were as follows:
(1) Wettability of Pb to Fe plates was significantly affected by oxygen in atmosphere; wetting proceeds successively with decreasing oxygen partial pressure. This is explained by the hydrogen-reduction of oxides on Pb drops and Fe plates. At constant oxygen partial pressure, wetting proceeds with raising temperature, this being explained mainly by the reduction of surface tension of liquid Pb.
(2) Addition of Sn to Pb is efficient in wetting to Fe plates, especially at lower temperature. In contrast to this, addition of Cu is effective at higher temperature. Addition of both Sn and Cu to Pb is most efficient in wetting to Fe plates over a range from lower and higher temperature.
(3) Infiltration of Pb to Fe green compacts is, as is in the wettability, difficult, but the addition of Sn or Cu to Pb improved the infiltration. Addition of both Sn and Cu improved the infiltration preferencially. Once these infiltrants start to penetrate into Fe green compacts, infiltration is accomplished completely in a few minutes.抄録全体を表示PDF形式でダウンロード (3910K) -
鈴木 良和, 広木 栄三, 窪田 大, 下川 勝義, 鵜沼 英郎1988 年 35 巻 8 号 p. 731-736
発行日: 1988/11/25
公開日: 2009/05/22
ジャーナル フリーRecently, a new technique, SHS process (Self-propagating High-temperature Synthesis), has been applied to the production of ceramic and metallic compound materials. The technique is characterized primarily by a large amount of heat of reaction which is produced during the sintering process and also, by a low production cost.
The analogous SHS process accompanied melting by exothermic reaction was observed during a two step heating of the Ni-Ti (50-50 at%) compact under a partial vacuum of 1 x 10-3 Pa: the exothermic melting reaction of the Ni-Ti compact took place at 820°C, when the temperature was quickly elevated from 600°C in the second heat stage. It was also observed that gases evolved from the compact during the two stage heat treatment.
This report shows that melted Ni-Ti alloys are obtained from 48 to 56 at%Ni in Ti by the processing, and the oxygen and the hydrogen are discharged from the compact with exothermic melting reaction in a short time, and consequently there is little oxygen and hydrogen in the compound with a homogeneous phase.抄録全体を表示PDF形式でダウンロード (5362K) -
金子 武, 天野 良成1988 年 35 巻 8 号 p. 737-741
発行日: 1988/11/25
公開日: 2009/05/22
ジャーナル フリーThe distribution of impurities (H, C, O, S, P, etc.) in the fracture surfaces of liquid sintered tungsten base composites has been measured by means of an Ion Microprobe Analyzer and also the mechanical properties have been investigate ?? .
Composites (91.3-95.5% W/5.8-3.0% Ni/2.9-1.5% Fe) were fabricated by the liquid phase sintering of powder (-2 μm) at 1460-1500°C in hydrogen atmosphere.
Three kinds of samples with different mechanical properties were analysed in terms of the amount of impurities in the tungsten grains, the binder phase and the interface between them.
Moreover, these materials were reheated at 1200°C for 9 hours in vacuo and at 850, 1050, 1250, and 1420°C for 6 hours in hydrogen atmosphere, respectively, and the impurities in the surfaces of these reheated test pieces were also analysed.
The existence of the impurities in the interface area was clarified. The mechanical properties were controlled by the strength of W-binder phase boundaries and W grain boundaries.
These findings support that the impurity segregation can be responsible for mechanical properties in the alloys.抄録全体を表示PDF形式でダウンロード (2838K) -
谷口 尚, 佐藤 隆, 近藤 建一, 澤岡 昭1988 年 35 巻 8 号 p. 742-747
発行日: 1988/11/25
公開日: 2009/05/22
ジャーナル フリーDynamic compaction of Fe-based amorphous alloy powder was performed by using a gun-type momentum trap method. Residual shock effects on the amorphous alloy samples was characterized by microstructural analysis (i.e. optical, SEM, and TEM observations), X-ray diffraction analysis, tensile strength test, and measurement of it's soft magnetic properties. Two attempts have been conducted to control the shock duration time and compression rate in the shock compaction process. It is found that magnetic properties of shock consolidated Fe-based amorphous alloy powder are strongly affected by impactor thickness which influences on shock duration time. The difference of the magnetic properties depending on the shock duration time is, however, reduced by appropriate heat treatments at the post shock stage. On the other hand, it is also found that a stepwise shock wave front structure, which can be produced by using the buffer material, is preferred to produce the consolidated amorphous alloy powder having superior soft magnetic properties.
The problems to produce the superior shock consolidated product of amorphous alloy were discussed, based on the results obtained in the present study.抄録全体を表示PDF形式でダウンロード (4497K) -
黒木 英憲1988 年 35 巻 8 号 p. 748-752
発行日: 1988/11/25
公開日: 2009/05/22
ジャーナル フリーCylinders, d40 mm×h40 mm for small-sized Charpy specimens and d10 mm×h10 mm for electrical conductivity measurements during compacting, and 10 mm cubes for dilatometry were compacted. Electrolytic and reduced-ore iron powders were pressed by admixing 0.7 mass% of zinc-stearate, or by die-wall lubricating alone under 98-588 MPa, de-waxed at 600°C for 30 min, anc sin tered at 1100°C for 60 min in dissociated ammonia. Small-sized Charpy specimens were cut out from the 40 mm cylinders in the pressing or axial direction, and in the radial direction. The electrical conductivity was measured in the 10 mm diameter die lined with zirconia. Cubic compacts for the dilatometry were compressed slightly in the compacting direction after ejecting from the die.
The toughness of the specimens with their length in the radial direction increased with test temperature, while those in the pressing direction remained almost constant, leading to an increased anisotropy of the toughness.
The electrical conductivity decreased more in the elctrolytic iron powder compacts than in the reducedore ones, and during the ejecting rather than during the unloading.
Re-pressing green compacts led to a decreased anisotropy of the toughness and decreased axial shrinkage during the sintering.抄録全体を表示PDF形式でダウンロード (1619K) -
河野 通, 山岸 宜行, 宮川 幸栄1988 年 35 巻 8 号 p. 753-756
発行日: 1988/11/25
公開日: 2009/12/04
ジャーナル フリーThe mechanical properties of 90%W-4%Mo-4%Ni-2%Fe sintered alloys were studied in this experiment.
The specimen which was not sufficiently reduced in the heating process before the rapid densification which occurred by the liquid generation (above 1453°C), showed inferior mechanical properties even if the sintering time was prolonged. It was considered that the deterioration of the mechanical properties was caused by the lowering of the boundary strength owing to the segregation of oxygen. The mechanical properties of the specimen which was sufficiently reduced and sintered, were much improved by the heat treatment. For example, mechanical properties of the specimen heated up at about 6.3°C, /min, sintered at 1500°Cfor 90 min in H2 and then quenched after keeping for 60 min at 1000°Cin N2 were as follows; the tensile strength is 96.7 kgf/mm2 and the elongation is 20.4%.抄録全体を表示PDF形式でダウンロード (3890K) -
金子 武1988 年 35 巻 8 号 p. 757-762
発行日: 1988/11/25
公開日: 2009/05/22
ジャーナル フリーThe present report describes the fracture toughness of W-Ni-Fe alloys. These alloys with nickel and iron as the constituent element (91.3-95.5% W/5.8-3.0% Ni/2.9-1.5% Fe) were fabricated by the liquid phase sintering of well grained powders (-2 μm) at 1460-1500°C in hydrogen atmosphere.
The microstructure of liquid sintered tungsten base composites consists of rounded and single crystal tungsten grains in a binder phase.
The fracture toughness of W-Ni-Fe heavy alloys was investigated with GVN slow bend specimens and cracked KIC specimens.
The CVN slow bend tests using standard CVN specimens and the static KIC bend tests using cracked specimens in accordance with the ASTM proposed for practice were carried out in the temperature range -40°C to +20°C.
As the results, it is confirmed that the fracture toughness, energy absorptions and static bending strength are dependent upon the W content, test temperature and strain rates.抄録全体を表示PDF形式でダウンロード (4365K) -
井手 恒幸, 中野 和属, 高木 研一1988 年 35 巻 8 号 p. 763-768
発行日: 1988/11/25
公開日: 2009/05/22
ジャーナル フリーEffects of Ni and C content on the liquid phase sintering of Fe-6 wt%B-48 wt%Mo-(0-7)wtooNi-(0.0l-0.3)wt%C alloys are studied by means of DTA, dilatometric measurements, microstructural observations and mechanical properties. The results are summarized as follows.
(1) In proportion to the increase of Ni and C contents, the temperature ranges of liquid forming reactions of γ-Fe+Fe2B→L1 and γ-Fe+Mo2FeB2→L2 shift to lower temperatures, respectively. As the C content increases, another liquid forming reaction, γ-Fe+Fe3C→Lc, occurs in addition to the L1 and L2 forming reactions. The Lc forming reaction occurs slightly below the temperature range in which the L1 reaction occurs.
(2) When the Ni content is in the range of 2-3 wt% and the C content is low (0.01 wt%), the sintered alloy consists of Mo2FeB2, a small amount of Fe2B as hard phases and a martensitic binder. However, transverse rupture strength and hardness are not improved.
(3) Highest transverse rupture strength values around 2.2 GPa are obtained for the Fe-6 wt%B-48 wt%Mo-3 wt%Ni-0.1 wt%Calloy, which consists of the martensitic binder phase.抄録全体を表示PDF形式でダウンロード (2786K) -
高木 研一, 駒井 正雄, 井手 恒幸, 渡辺 忠雄, 近藤 嘉一1988 年 35 巻 8 号 p. 769-774
発行日: 1988/11/25
公開日: 2009/12/04
ジャーナル フリーFe-5B-xMo model alloys with five levels of Mo content corresponding to Mo/B atomic ratio ranging from 0.7 to 1.1 were prepared to study the effects of Mo/B atomic ratio on the mechanical properties and phase formation during liquid phase sintering. The effects of Mo/B ratio on the morphology, chemical composition and lattice parameters of a Mo2FeB2 type complex boride were also studied.
In conclusion, a high transverse rupture strength of approximately 2.2 GPa was obtained for the alloys when Mo was added to match the stoichiometric Mo/B atomic ratio, 1.0 of Mo2FeB2. In addition to the two main constituents, namely the Mo2FeB2 type complex boride and the ferrous binder, in the Mo deficient alloys of which Mo/B atomic ratio was below 1.0 the Fe2B was detected as a third phase, while Mo excess alloys of which Mo/B atomic ratio was above 1.0 contained M6C (M: Metal). The morphology, chemical composition and lattice parameters of the Mo2FeB2 type complex boride varied when the Mo/B atomic ratio of the alloy was high in a manner related to the atomic ordering in the Mo2FeB2 structure.抄録全体を表示PDF形式でダウンロード (3635K) -
小堀 景一, 植木 光生, 谷口 〓朗, 鈴木 寿1988 年 35 巻 8 号 p. 775-780
発行日: 1988/11/25
公開日: 2009/05/22
ジャーナル フリーThe flank wear (VB) of cemented carbide tool affected by cutting fluids, that is, water soluble cutting fluid (W.S; JIS WI-1) and non-water soluble one (Non-W.S; JIS 2-3) was studied in drilling tests of S45C. When the true cutting speeds (vi) at the fixed position of cutting edge were noted, a single curve was obtained between VB and vi for each fluid, the shape of curve being very similar to the one well known in dry turning tests. It was found that the VB-vi curve of W.S shifted to the higher speed side comparing with the one of Non-W.S, so that the VB at lower vi increased markedly for W.S. It was also found that the VB at low vi was promoted for W.S, because carbide grains dropped out from the cutting edge plowed the flank face. This phenomenon in W.S was attributed to the so much larger cooling effect of W.S than the other.抄録全体を表示PDF形式でダウンロード (4350K) -
評価アルゴリズムの提案とPSZの寿命予測杉田 忠彰, 上田 完次, 西 誠1988 年 35 巻 8 号 p. 781-786
発行日: 1988/11/25
公開日: 2009/05/22
ジャーナル フリーThe main objective of this study is to evaluate the strength reliability of ceramics for mechanical com-ponent applications based on fracture mechanics. This paper discribes an algorithm for the strength reliability evaluation of ceramics and prediction of the life of PSZ (Partially Stabirized Zirconia) components according to the proposed algorithm. Extensive crack growth is observed prior to the final fracture during cyclic three-point bending and it is confirmed that PSZ exhibits a linear relationship on logarithmic scale between the fatigue crack growth rate da/dN and the stress intensity factor range ΔK. Statistical charac-teristics of the crack growth rate parameters C, m and the fatigue fracture toughness value Kfc are also found to fit well with Weibull distribution. It was found that the estimated life of PSZ components decreases with increasing stress range and initial crack length and with decreasing fracture probability.抄録全体を表示PDF形式でダウンロード (1584K) -
山本 孝, 岡崎 清1988 年 35 巻 8 号 p. 787-792
発行日: 1988/11/25
公開日: 2009/05/22
ジャーナル フリーIn general, the porous lead- titanate-zirconate ceramics, Pb(Zr, Ti)O3 exhibit the excellent properties for ultrasonic sensor, though the mechanical properties are not so good for their porous structure. The wide application for electronics components was restricted because of their poor reliance. In this study, the Pb(Zr, Ti)O3/SiC whisker composites (PZT/SiC) were prepared by the normal ceramics processing. With the increase in the contents of SiC whisker, the electrical and mechanical properties changed gradually. For the study of the change in properties, the microstructures were investigated by the scanning electron microscopy (SEM) and transmittion electron microscopy (TEM). The results obtained is as follows;
SiC+2O2 ?? SiO2+CO2
SiO2+Pb(Zr, Ti)O3 ?? Pb, Zr, Ti, Si glass.
The grain boundary and three pockets were coated by this glass. As a result, the mechanical properties of bending strength and fracture toughness, K1c increased. By using this idea, the porous PZT ultrasonic sensor with a high mechanical strength has been developed and the excellent sensor properties were obtained;
piezoelectric constant=99-110×10-3 Vm/N
bending strength =50 kg/cm2.抄録全体を表示PDF形式でダウンロード (2420K) -
上山 守, 和田 弘, 上原 秀秋1988 年 35 巻 8 号 p. 793-798
発行日: 1988/11/25
公開日: 2009/05/22
ジャーナル フリーWe studied the effects of alumina content and firing temperature on the electrical properties of alumina substrate. Alumina content was varied within the range 91.5% to 98.8%, and firing temperature, within the range 1, 480°C to 1, 640°C. The higher the firing temperature, the greater become the volume resistivity, Te value, dielectric constant (ε), and dielectric loss tangent (tan δ). When the alumina content is increased, the coefficient of electric loss (ε×tan δ) which is a representative parameter of substrate properties of high frequency decreases, while the volume resistivity, a representative parameter of substrate insulated properties, and the Te value remain invariable.抄録全体を表示PDF形式でダウンロード (377K) -
勝村 祐次, 小林 正樹, 小堀 景一, 鈴木 寿1988 年 35 巻 8 号 p. 799-804
発行日: 1988/11/25
公開日: 2009/12/04
ジャーナル フリーThe cutting performance (flank wear VB, flank notch wear VN) of Al2O3-25 vol%SiC ceramics tool for such works as cast iron (FC35), steel (S48C) and Inconel 600 was examined in comparison with that of Al2O3-25 vol%TiC and Al2O3-30 vol%SiC whisker ceramics tools. The results obtained were briefly summarized as follows: The Al2O3-TiC ceramics tool showed the smallest VB and largest VN for Inconel 600, among three sorts of tools, reflecting the difference of the reactivity between TiC and SiC to the works and that of the resistance to oxidation between TiC and SiC contained ceramics, rspectively. Comparing Al2O3-SiC ceramics tool to Al2O3-SiC whisker one in cutting tests of Inconel 600, VB and VN of the former were somewhat smaller and larger, respectively. The phenomenon was explained by the fact that, in the SiC whisker contained tool, the reactivity on the works was enhanced, but abrasive wear at flank notch was checked, owing to the anisotropic array of whiskers like sticking the flank surface from inside.抄録全体を表示PDF形式でダウンロード (4554K)
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