巻号一覧
52 巻, 11 号
選択された号の論文の21件中1～21を表示しています
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仲田 清智, 吉田 寿美, 正岡 功, 斎藤 隆, Jacobs A. J., Wozadlo G. P., Yang W. J. S.1988 年 52 巻 11 号 p. 1023-1030
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーAustenitic stainless steels of Types 316 and 304 were neutron-irradiated up to 2.5×1025 n/m2 (>1 MeV) at 560 K, and the tensile test was performed at 561 K. An increase in yield strength and a decrease in both elongation and work-hardening rate were observed with irradiation dose in the solution-annealed specimens. These mechanical property changes in Type 316 steels were smaller than those in Type 304 steels. The addition of nitrogen to the steels was beneficial for suppression of radiation embrittlement, because the smallest reduction of elongation with irradiation occurred in the specimens with nitrogen of about 0.1%. On the contrary, a large reduction of elongation occurred in the specimens with a remarkably small amount of Si and other impurities. Smaller irradiation-induced changes in tensile properties were observed in the 20% cold-worked specimens than in the solution-annealed ones, and the effects of solute atoms were not observed clearly. The responce of the low-temperature sensitized specimens was similar to that of the solution-annealed ones.抄録全体を表示PDF形式でダウンロード (1769K) -
竹内 栄1988 年 52 巻 11 号 p. 1031-1038
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe latent heat of vaporization in the liquid state of metals in the temperature range from the melting to the boiling point is not so much different from the cohesive energy in the crystalline state near the melting temperature Tm. The energy of mutual interaction between neighbouring atoms in the liquid state is considered to be close to that in the solid state at Tm. The observed mean distance between neighbouring atoms is approximatly constant independent of temperature. The volume expansion with increasing temperature in the liquid state originates from the increase in the equilibrium concentration of vacancies included in the random close packed arrangement of atoms. The mobility of a vacancy in the random distribution of atoms is exceedingly higher than that in the ordered arrangement of atoms in the crystal. The migration of vacancies plays an essential role for the fluidity of liquid. The diffusion costant and the viscosity coefficient are evaluated as a function of vacancy concentration in good agreement with the observed values for liquid Pb, Na and K.抄録全体を表示PDF形式でダウンロード (1173K) -
竹内 栄1988 年 52 巻 11 号 p. 1039-1042
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe entropy change on melting ΔS for metals with the B.C.C. structure is about 0.75 of ΔS for metals with the F.C.C. structure. The mean distance between neighbouring atoms \barR observed experimentally in the liquid state of F.C.C. metals is very close to the atomic distance Rs in the solid state at the melting temperature, but \barR in the liquid state of B.C.C. metals is considerably larger than Rs. The atomic distribution in liquid state of B.C.C. metals is shown to be in the random close packed arrangement same as that in the liquid state of F.C.C. metals. From this fact, it is supposed that B.C.C. metals transform to the liquid state through a transient stage of the F.C.C. structure on melting. The latent heat of transition from the B.C.C. structure to the transient stage reduces the thermal energy neccessary for fusion of B.C.C. metals. From this point, the latent heat of fusion and the entropy change on melting for B.C.C. metals are evaluated.抄録全体を表示PDF形式でダウンロード (506K) -
佐藤 英一, 栗林 一彦, 堀内 良1988 年 52 巻 11 号 p. 1043-1050
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーDuring superplastic deformation, grain growth occurs more rapidly than without deformation, which can be divided into two components, the deformation induced (∂\barD⁄∂ε)t and the static (∂\barD⁄∂t)ε . In the present study, a method to separate these components is developed analytically. The former can be evaluated approximately by (\barD⁄\barDs), where \barD and \barDs are grain sizes after deformation and after the equivalent annealing without deformation, respectively. The deformation induced component causes flow hardening presented by the flow hardening parameter γ=mp(∂ln\barD⁄∂ε)t, where the constitutive equation is expressed as \dotε=K\barD−pσ1⁄m. Flow hardening stabilizes the deformation itself alike the work hardening at the ambient temperature.
The method to separate these two components is confirmed experimentally using microduplex Zn-22%Al alloy. In the superplastic deformation region, the deformation induced component is independent of strain rate, deformation temperature and initial grain size, as well as the magnitude of the static grain growth. Besides, it is indicated by ln(\barD⁄\barDs)=αε, where α\simeq0.3. The observed increase of flow stress under the constant strain rate tests can be ascribed to the whole grain growth.抄録全体を表示PDF形式でダウンロード (1312K) -
佐藤 英一, 栗林 一彦, 堀内 良1988 年 52 巻 11 号 p. 1051-1056
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーPlastic instability has been reanalyzed for superplastic materials with the strain rate sensitivity m and the flow hardening parameter γ. The condition under which a neck does not grow has been obtained as I≡(γ−1)⁄m≥0. Even though I<0, the neck broadens gradually provided I≥−1. In the case of −1>I>−2, the neck becomes initially sharper but it finally becomes broader. If I≤−2, the neck becomes sharp. Although the usual superplastic deformation is thought to proceed in an unstable state because I<0, a large elongation can take place provided that I>−2 and the neck becomes broader.抄録全体を表示PDF形式でダウンロード (782K) -
野末 章, 大久保 忠恒1988 年 52 巻 11 号 p. 1057-1062
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe purpose of the present paper is to clarify fatigue crack growth behavior in Ti-6Al-4V alloy consisting of primary α and matrix. The phase ratio of the primary α to the matrix was varied from about 65 to 20% with the solution treatment. The temperature range for this treatment was between 1148 and 1228 K. Fatigue tests were carried out in the ΔK region from the fatigue threshold to the critical fatigue fracture under constant load amplitude with CT specimens of 6 mm thickness. The crack propagated preferentially in the primary α phase compared with the matrix. On the fracture surfaces of the primary α phases, comparatively flat facets were observed in the low ΔK region and the striations were clearly observed in the high ΔK region. In addition, martensite boundary cracks existed in the matrix. It was found that the primary α fraction mainly controlled the fatigue crack growth rate in the region of the stable crack growth.抄録全体を表示PDF形式でダウンロード (2895K) -
小原 嗣朗, 武藤 範雄1988 年 52 巻 11 号 p. 1063-1069
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe degradation behavior of carbon fibers was investigated by measuring the change in tensile strength of the fibers. The fibers used in the present study are PAN-based HS type (Toray T-300), PAN-based HM Type (Toray M-40) and pitch-based (Kureha T-101S) fibers. Tows of carbon fibers were impregnated with the slurry of aluminum powder and then hot pressed in vacuum at temperatures at which aluminum becomes the liquid phase. The matrix of the hot pressed composites was dissolved with sodium hydroxide solution and the fibers were extracted from the composites. The extracted fibers were tension tested with a testing machine for mono-filament. The pitch-based carbon fibers were less degraded by molten aluminum compared with the PAN-based carbon fibers. The degradation of PAN-based carbon fibers depends on the temperature and holding time. At lower temperatures, the HS type carbon fibers were more degraded than the HM type carbon fibers in the early stage, but the HM type carbon fibers were more degraded in the later stage. At higher temperatures, the HM type carbon fibers were more degraded than the HS type carbon fibers from the early stage. The difference in the degradation behavior of the carbon fibers is attributable to the morphology of Al4C3 crystals formed at the interface between the fiber and molten aluminum.抄録全体を表示PDF形式でダウンロード (1208K) -
吉葉 正行, 宮川 大海, 水野 裕之1988 年 52 巻 11 号 p. 1070-1079
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーIn order to clarify an effect of material factors on the creep rupture properties of heat resisting alloys subjected to hot corrosion, creep rupture tests were performed of fourteen commercial heat resisting iron-nickel-chromium alloys at 1073 K in air and in the simulated hot corrosive environment using the 90%Na2SO4-10%NaCl salt mixture. The corrosion sensitivity of the creep rupture properties was found to be different considerably among the alloys, depending mainly on the alloy systems and the strength levels associated with a strengthening mechanism. In particular, the γ′ precipitation-hardened nickel-base superalloys with a Ni content more than approximately 70% yielded the most significant rupture strength degradation due to hot corrosion in spite of their inherent high-strengths. On the contrary, the precipitation-hardened nickel-iron-base superalloys exhibited the most improved rupture strength even in such an aggressive environment along with the minimized corrosion sensitivity.
From the metallographic examinations of both creep-ruptured and creep-interrupted specimens by means of optical and electron microscopy along with X-ray microanalyses, it was revealed that the difference in such a corrosion sensitivity of the creep rupture properties was closely related with a change in the creep rupture behavior due to hot corrosion. The corrosion creep rupture behavior of different alloys was classified into three types, being associated with the resistance of each alloy to an aggressive intergranular attack under the applied stress. Furthermore the materials factors affecting the corrosion rupture properties were discussed mainly from the aspect of alloy chemistry.抄録全体を表示PDF形式でダウンロード (2380K) -
佐貫 須美子, 長谷川 昌弘, 新井 甲一, 位崎 敏男, 真嶋 宏1988 年 52 巻 11 号 p. 1080-1087
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe feasibility of new recovery process of pure alumina from the waste acid solution of electro-condenser works was investigated from a thermodynamic consideration and an experimental study based on the results of solvent extraction of Fe3+ and Al3+ from the waste acid solution, the crystallization of AlCl3·6H2O with HCl gas from the waste acid solution, the calcination of AlCl3·6H2O and the X-ray diffraction analysis of Al2O3.
The experimental results are summarized as follows:
(1) The extraction of Fe3+ with Amberite LA-1 from the waste acid solution in electro-condenser works is available. However, the extraction of Al3+ with Versatic Acid 10 is not so effective that it is difficult to use the separation of Al3+ from the waste acid solution containing a high concentration of Al3+.
(2) The crystallization of AlCl3·6H2O with HCl gas from the waste acid solution is available, and AlCl3·6H2O of high purity is obtained. However, the crystallization of AlCl3·6H2O with HCl gas from the waste acid solution containing a high concentration of Fe3+ is contaminated with Fe3+. Therefore, the removal of Fe3+ is necessary before the crystallization of AlCl3·6H2O.
(3) High-purity Al2O3 can be recovered by the calcination of AlCl3·6H2O.
(4) From the thermodynamic consideration and the experimental study, it is concluded that a new recovery process of pure alumina from the waste acid solution in electro-condenser works is available.抄録全体を表示PDF形式でダウンロード (1134K) -
和才 京子, 向井 楠宏1988 年 52 巻 11 号 p. 1088-1097
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThermodynamic properties of Fe-Al-O liquid alloy in equilibrium with α-Al2O3(s) were analysed by an associated solution model assuming the associated compounds, Fe3Al(a), FeAl(a), FeAl3(a), FeO(a), FeO·Al2O3(a), Al2O3(a) and Al2O(a). The results obtained are as follows.
(1) The calculated equilibrium curve (E.C.), that is, the relation between log[%O] and log[%Al] of the liquid alloy at 1873∼2183 K, has a minimun value of [%O] at [%Al]=0.5∼0.8 and a minimun value of [%Al] at [%O]=0.007∼0.045. This E.C. describes well the experimental data obtained by various investigators. The shape of E.C. characterized by the minimums is caused by the concentration changes of the associated compounds.
(2) Calculated [%Al] of the liquid alloy equilibrated with both Al2O3(s) and FeO·Al2O3(s) is by 1000 times larger than the activity, aAl,%\invdiameter at 1873 K.
(3) Contents of insoluble Aluminum (lnsol Al) in the liquid alloy were calculated by the assumption that they consisted of solidified associated compounds, FeO·Al2O3(s), Al2O3(s) and Al2O(s) which were insoluble in acid. The calculated and observed lnsol Al contents agreed well each other.
(4) Calculated relationships of logfO vs. [%Al] and logfAl vs. [%O] on E.C. are not linear. The discrepancies of the reported values of eOAl, eAlO and deoxidation constant K′ between various investigators are attributed to the treatments assuming that these relations are linear.抄録全体を表示PDF形式でダウンロード (1401K) -
原 茂太, 荻野 和巳1988 年 52 巻 11 号 p. 1098-1102
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーDensities and surface tensions of CaF2-MO(M: Mg, Ca, Ba) binary melts were measured by the Archimedean method and the maximum bubble pressure method, respectively. The results obtained were as follows:
(1) Molar volumes of the melts in the binary systems CaF2-MO satisfied the additive rule on volume. From the results obtained, the densities of the hypothetical melts of MgO, CaO and BaO at 1827 K were estimated to be 2.64×103, 2.66×103 and 4.49×103 kg/m3, respectively.
(2) On the basis of the findings on the density and surface tension, it is suggested that the CaF2-BaO binary system should be treated as a CaF2-CaO-BaF2 ternary system.
(3) The melts of the CaF2-MgO and CaF2-CaO systems can be treated as the regular solutions. The interaction parameters are estimated to be 22 kJ/mol for the CaF2-MgO system and 40 kJ/mol for the CaF2-CaO system.抄録全体を表示PDF形式でダウンロード (737K) -
柏谷 悦章, 石井 邦宜1988 年 52 巻 11 号 p. 1103-1112
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe morphology and formation mechanism of carbon decomposed from CO gas on pure iron foil has been investigated at temperatures from 673 to 973 K. Carbon formed on iron foil consisted of two types of carbon, the particle-like carbon in the surface of the deposited layer and the fiberous one in the inner layer. On the other hand, the carbon deposited on powdery carbonyl iron was also fiberous. Thus the most of the precipitated carbon was fiberous. The carbon fiber had always a particle composed of C and Fe, so it appeared to grow from the particle acting as catalyst. The selected area diffraction (SAD) pattern of the particle was consistent with that of Fe-C (ASTM 3-0400), which has been known as the Fe-bearing graphite solid solution. The particle decomposed to the stable compound of Fe3C and ordinary graphite during annealing (773 K, 1.8×104 s) in He. A similar reaction proceeded under electron beam irradiation in an ultra-high voltage electron microscope (UHVEM), and it was found that the particle transformed to a stable phase through a Fe-C→Fe5C2→Fe3C process.
It was also observed by the UHVEM that each fiber was composed of a finer texture of graphite. The angle between the graphite ⟨002⟩ and the direction of fiber growth was about 20° and ⟨002⟩(Fe-C)\varparallel⟨002⟩(graphite). The mechanism of growth of the fiber was considered from those experimental results as follows: (1) CO molecule adsorbs on Fe-C making the atmosphere around the Fe atom in catalyst. (2) The CO adsorbed decomposes to the carbon atom and CO2, and then the free carbon atom accumulates as intercalant between Fe-C(002) carbon planes. (3) As the intercalated carbon atoms increase, the atoms form a new A-stacking plane of Fe-C. (4) The old A-plane of Fe-C moves to the [111] direction, that is, the direction of fiber growth, and forms a new B-stacking plane of graphite. Then the growth axis and [002] of graphite make an angle of 20°, in good agreement with the value obtained by electron microscope observations.抄録全体を表示PDF形式でダウンロード (3894K) -
真島 一彦, 平田 武彦, 山本 光政, 永井 宏, 庄司 啓一郎1988 年 52 巻 11 号 p. 1113-1120
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーStatic tensile properties of as HIP’ed Ti-Fe alloys and heat treated Ti-Fe alloys after HIP were studied, and metallographic and fractographic observations were also carried out by means of the back scattered electron images and a scanning electron microscope.
Despite the low level of oxygen content, the HIP’ed specimen using Hunter Process sponge fines as the titanium source showed poorer ductility than the HIP’ed specimen using hydride-dehydride Kroll process sponge fines of high oxygen content as the titanium source.
The improvement of the mechanical properties was not recognized neither by the two step HIP treatment of HIP’ing at 973 K in the (α+β)-region after HIP’ed at 1223 K in the β-region, nor by (α+β)-quenching after β solution treatment, where the acicular like α phase was recognized in the two step HIP treated specimen, and the grain coarsening and grain boundary α phase were recognized in the (α+β)-quenched specimen. The mechanical properties, however, were remarkably improved by the method in which the β solution treatment was first carried out on the as sintered Ti-Fe specimens, and then the specimens were hot isostatically pressed in the (α+β)-region.抄録全体を表示PDF形式でダウンロード (2841K) -
稲葉 道彦, 野村 貴美, 氏平 祐輔1988 年 52 巻 11 号 p. 1121-1126
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーSheets of the invar alloy (Fe-36Ni), a useful material of shadow mask in color television, were vacuum-annealed in 10−2 Pa at temperatures from 1273 to 1473 K for 3.6 ks.
Enriched impurities and the Ni/Fe ratio change on the surface layer were analyzed by the Auger electron spectrometer with Ar ion sputter-etching. Lattice parameters of the sample surface layers were calculated using (220) peaks/obtained by a thin film X-ray diffractmeter. Their internal magnetic fields were analyzed by conversion electron and X-ray Mössbauer spectra. These data are compared with the lattice parameters and Curie temperature diagrams in bulk of the samples, and the influence of surface enrichment phenomena on them were discussed. The results obtained are as follows.
(1) As the annealing temperature increased, the surface enrichment of chromium and the surface decrease of nickel were accelerated. In the 1473 K sample, the surface chromium concentration was about one thousand times as large as that in the bulk, and its enrichment layer thickness is less than 10 μm.
(2) The lattice parameters of the surface layers decreased in the range of 0.001 nm. Half of this decrease arises from the chromium enrichment and the rest from the decrease of nickel.
(3) The internal magnetic field decreased with increasing annealing temperature. In the 1473 K sample, ferromagnetism disappeared at the surface layer. These results suggested that chromium was solid-soluted in the surface layer phase.抄録全体を表示PDF形式でダウンロード (1243K) -
村山 順一郎, 幸 英昭, 工藤 赳夫1988 年 52 巻 11 号 p. 1127-1136
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーCorrosion films formed on high alloyed materials in aqueous H2S-Cl− environments at high temperature have been investigated from the standpoint of the corrosion resistance. The surface film thickness decreases with increasing corrosion resistance. Nickel-based alloys have high corrosion resistance as compared with iron-based alloys. Chromium and molybdenum were the alloying elements which improved the corrosion resistance. The corrosion films formed on the iron-based alloys in the H2S-Cl− environment have a double layer structure which was composed of Fe-S in the outer layer and Fe-Cr-O-S in the inner layer, while the nickle-based alloys have a double layer structures, Ni-S in the outer layer and Cr-OH in the inner layer. These differences in film structure between the iron- and nickel-based alloys could be understood in terms of the solubilities of sulfides and oxides of Cr, Ni and Fe in solutions adjacent to the alloy surface. The formation of the Cr-OH layer is essential to maintain the corrosion resistance in these environments. The reason why the nickel-based alloys have higher corrosion resistance than the iron-based alloys is that the former is liable to produce a pure Cr-OH layer.抄録全体を表示PDF形式でダウンロード (2260K) -
秋山 哲也, 寺崎 俊夫, 米田 博之1988 年 52 巻 11 号 p. 1137-1143
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーThe effect of cold working following the sensitizing heat treatments on the degree of sensitization ratio, the effect of cold working before the sensitizing heat treatments on the time at which the degree of the sensitization shows a maximum value, and the effect of cold working on this maximum value have been investigated by the reactivation ratio obtained from the EPR test.
The materials used in this experiment were type 304 stainless steel plates having 0, 5, 15 and 30% plastic strains. For the sensitizing heat treatments, isothermal heat treatments were used.
The cold working following the sensitizing heat treatments does not affect the degree of sensitization. However, before the sensitizing heat treatment, it shortens the time needed for the degree of sensitization to reach the maximum value, but it does not affect this maximum value.抄録全体を表示PDF形式でダウンロード (1551K) -
渡辺 隆二, 安藤 寿, 岩下 喜代次, 黒沢 幸夫1988 年 52 巻 11 号 p. 1144-1148
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーVarious electrode materials for low surge vacuum circuit breakers which were impregnated with silver-10 mass%Te alloy into the sintered matrices of Co, Fe, Ni, Cr, Fe-50 mass%Co and WC-12 mass%Co were prepared in vacuum.
The microstructures and basic electrical properties for the electrodes have been examined. Silver-10 mass%Te can be impregnated to the Co, Fe, Ni, Fe-Co matrices very well. Defects are not found in these alloys at all.
The maximum chopping current values of the materials are approximately 2∼3 A and the average are in the range of 1∼2 A except (WC-Co)-(Ag-Te).
Especially the chopping currents of Co-(Ag-Te) and (Fe-Co)-(Ag-Te) electrodes are very stable and low even after interruptions.
Further, it has been found that the materials are superior in withstand-voltage and interruption-ability to the conventional electrode (Cu-0.75 mass%Pb).抄録全体を表示PDF形式でダウンロード (1018K) -
伊藤 操, 吉田 総仁, 大森 正信1988 年 52 巻 11 号 p. 1149-1153
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーIn the strain rate range from 8.5×10−5 to 4.5×10 s−1, a low carbon steel with small crystal grains or with a small critical impact tensile velocity was tested in tension at the atmospheric pressure after being pressurized or under hydrostatic pressure. The findings in the present investigation are summarized as follows:
(1) The yield stress of the pressurized specimen quasi-statically tested at the atmospheric pressure began to decrease at a pressurization of 400 MPa, while the decrease in the stress of the specimen tested under hydrostatic pressure began to occur at the considerably lower pressure of 250 MPa. The tensile strength was unchanged by the pressure in both tensions.
(2) The fracture elongation measured in a quasi-static tension was 40%, being independent of the pressure. Although the elongation in a high speed tension (900 mm·s−1 in tensile speed and 4.5×10 s−1 in strain rate) was about 12% at the lower pressure, it began to increase at a pressurization of 400 MPa or at 250 MPa in the tension under pressure. The pressure of 400 or 250 MPa at which the elongation began to increase was quite the same as the pressure at which the yield stress began to decrease. This implies that the critical impact tensile velocity of the specimen was increased by lowering the yield stress.
(3) The strain rate sensitivity of the yield stress was considerably smaller in the pressurized specimen than in the specimen without pressurization. However, the sensitivity of the flow stress at a larger strain beyond the Lüders elongation was as small as the sensitivity of the yield stress for the pressurized specimen and was independent of pressurization treatment.抄録全体を表示PDF形式でダウンロード (838K) -
田畑 裕之, 平野 敏幸1988 年 52 巻 11 号 p. 1154-1158
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーSingle crystal growth of MoSi2 was carried out by the floating zone method using infrared heating. The following results were obtained:
(1) The large single crystals 6∼8 mm in diameter were successfully grown toward [100] and [001] directions.
(2) The crystal faces of {013} or {001} were clearly observed on the [100] oriented crystal parallel to the growth direction. However, no crystal face was observed on the [001] oriented crystal, and fine cylindrical stripes following the fluctuation of diameter were observed.
(3) The chemical compositions of the crystals were slightly Mo rich (about 0.9 at%) as compared with the stoichiometric composition. There was a very small compositional fluctuation along the growth direction.
(4) The refinement of the MoSi2 crystals was carried out by the Rietveld analysis of X-ray powder diffraction patterns. The 2a-site occupancy by Mo is 0.988 and the 4e-site occupancy by Si is 0.981. These values show that the grown single crystals are highly ordered.
The technique of MoSi2 single crystal growth by the floating zone method has been established.抄録全体を表示PDF形式でダウンロード (752K) -
橋本 健紀, 土肥 春夫, 笠原 和男, 中野 理, 辻本 得蔵, 鈴木 朝夫1988 年 52 巻 11 号 p. 1159-1166
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーMechanical properties of intermetallic compound TiAl base alloys which contain Nb, Zr, Mn or V as the third element have been examined at room temperature by means of hardness, compression and bending tests. The following results have been obtained, and the relation between ductility and metallographic factors reported in our previous paper has been discussed.
Plastic deformation at failure in the compression and bending tests increases by the additions of a small amount of V or Mn to two-phase alloys consisting of TiAl(γ) and Ti3Al(α2). In the case of Zr addition the ductility is not improved, but the strength at failure in the compression or bending tests increases remarkably, although the existing phases in the alloys is not altered. For γ single-phase alloys containing a larger amount of Nb the ductility is improved.
Four factors are considered important for improving the ductility in the TiAl base alloys containing the third elements: The fineness of microstructures, the increase of annealing twins in the γ phase, the decrease of the α2 phase, and the decrease of Al content in the γ phase. These factors can be controlled by selecting the kind and amount of the third element.抄録全体を表示PDF形式でダウンロード (1410K) -
仲田 清智, 吉田 寿美, 正岡 功, 斎藤 隆, Jacobs A. J., Wozadlo G. P.1988 年 52 巻 11 号 p. 1167-1168
発行日: 1988年
公開日: 2008/04/04
ジャーナル フリーPDF形式でダウンロード (438K)
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