巻号一覧
37 巻, 1 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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山本 博司1973 年 37 巻 1 号 p. 1-8
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーThis Study was intended to clarify the embrittlement of a doped tungsten wire by recrystallization.
The samples were tungsten wires of 0.205∼0.450 mm in diameter doped with Al, Si and K which were calculated to be 0.035∼0.050% Al2O3, 0.21∼0.30% SiO2 and 0.35∼0.50% K2O for W4O11. These wires were isothermally annealed at 2000∼2700°C and subsequently the changes in the structures and tensile properties were examined. Furthermore, the fracture of the secondarily recrystallized wires after the tensile test was observed, and the preferred orientation of the secondarily recrystallized grains was determined.
The doped tungsten wires usually become brittle by recrystallization. The embrittlement behavior of the wires depends on the annealing conditions. The following were the major results obtained:
(1) The wires, which had been highly doped, heavily worked (thin in diameter) and secondarily recrystallized at temperatures below 2300°C, showed relatively low yield points and high elongation, exhibiting high ductility.
(2) The grains in such wires were extraordinarily large with the preferred orientations near ⟨431⟩ or ⟨321⟩ and had extremely long and complicated boundaries.抄録全体を表示PDF形式でダウンロード (1225K) -
鈴木 寿, 林 宏爾, 棚瀬 照義1973 年 37 巻 1 号 p. 9-13
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーStudies on the recovery or aging processes in WC-Co alloy were carried out by means of specific heat measurements. Various specimens different in cobalt content, carbon content, mean grain size of WC and compressive strain were prepared. Structural changes corresponding to specific heat changes were examined by the X-ray diffraction method and transmission electron microscopy.
The results were summarized as follows: (1) The high carbon alloy: In the as-sintered specimen of high cobalt content (∼45%), a heat absorption probably due to the ε→γ reverse-transformation was only observed in the temperature range of about 480∼660°C. In the strained specimen (∼45% Co), a heat evolution probably due to the dislocation recovery in the binder phase was first observed above ∼400°C and then a heat absorption mainly due to the ε′→γ transformation was observed.
(2) The low carbon alloy: The heat evolution due to the precipitation of Co3W increases with increasing strain and decreasing grain size of WC, independently of cobalt content. As to the strained specimen, no heat evolution due to recovery or absorption due to transformation was not observed even in the high cobalt alloy. (3) A heterogeneous precipitation of Co3W on stacking faults in the binder phase was observed in the transmission electron micrographs. This fact would confirm the accelerated precipitation in the strained specimens as mentioned above.抄録全体を表示PDF形式でダウンロード (564K) -
鈴木 寿, 菅野 幹宏1973 年 37 巻 1 号 p. 13-18
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーThe effects of quenching and aging temperatures on the initial aging curves of Cu-Cr alloy were examined mainly by means of electrical resistivity measurements. Three Cu-Cr alloy specimens having 0.24, 0.74 and 1.0% Cr were solution-treated at 950∼1050°C, quenched into ice-water and subsequently aged at 300∼500°C.
The results obtained were as follows:
(1) At the very early stage of aging (within about 30 sec), an abrupt decrease of resistivity with lowering aging temperatures (TA) and rising solution temperatures (Ts) was observed at TA up to about 400°C. In contrast, a transient increase of resistivity with rising TA and lowering Ts was observed at TA from about 450 to 500°C. These phenomena seem to be caused by a rapid formation of solute clusters and the reversion of clusters formed during quenching, which are enhanced by quenched-in vacancies, respectively.
(2) The amount of precipitation increased at the latter stage of aging with rising Ts and TA as generally expected, where Ts was not so high as to form secondary defects.
(3) As a result, the initial aging phenomena in Cu-Cr alloy were revealed to be complicated against expectations. This was considered to be due to the migration energy of vacanciesso larger in Cu-base alloys than that in Al-base alloys, that the clustering or reversion phenomena at the initial stage of aging could be detected.抄録全体を表示PDF形式でダウンロード (502K) -
時沢 貢1973 年 37 巻 1 号 p. 19-25
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーDuring the compressive deformation of metals the lubricant trapping is enhanced by the formation of metal surface pits which are caused by local deformations under the hydrostatic pressure effect of trapped lubricants at a tool-metal interface. The present paper describes the results of a detailed study on the development of surface asperities produced during cold compression of single crystals, bicrystals and polycrystals of aluminum as well as polycrystalline copper, iron and zinc. The following results are obtained, for which a model of lubrication mechanism is proposed.
(1) It is observed that the amount of surface pits of deformed metals is much larger in polycrystalline metals than in single crystals. It is also found that the grain-boundary angle and the slip-direction depending upon crystal orientations affect markedly the formation behavior of surface pits.
(2) The low coefficient of friction observed in materials of small grain size can be explained by the fact that the amount of lubricants trapped in surface pits formed during the deformation is large in these materials.
(3) The distance between the micro-plateau of surface asperities is found to be nearly equal to the grain size in fcc and bcc metals such as Al, Cu and Fe, and each grain contributes to one micro-plateau. In hcc metals such as Zn and Mg, an aggregate of several grains contributes to one micro-plateau on the deformed metal surface.抄録全体を表示PDF形式でダウンロード (1119K) -
喜多 清, 松田 昭三, 苧野 兵衛, 中村 宏, 堀川 武, 岡崎 章三1973 年 37 巻 1 号 p. 26-32
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーThe relation between fatigue strength and micro-structure of tufftrided mild steel (SS 41, S 15CK) has been studied by means of fatigue test, optical and electron micrography, the hardness test and X-ray diffraction. The results obtained are summarized as follows:
(1) Fatigue strength of SS 41 by a Schenck fatigue tester is increased with tufftriding time.
(2) S 15 CK tufftrided specimens are examined by Ono fatigue tester. It’s strength is reduced by tempering.
(3) According to tempering conditions, two types of plate-like nitride are precipitated in the diffusion zone. The larger one is γ′-Fe4N and the smaller is α″-Fe16N2.
(4) In addition to fatigue striations and rub marks, tire tracks are observed in the diffusion zone of the fracture surface.抄録全体を表示PDF形式でダウンロード (1276K) -
藤村 全戒, 石井 仁1973 年 37 巻 1 号 p. 33-39
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーTo provide a better understanding of the mechanical properties of high Cr-low Ni two-phase stainless steels, tensile behaviors at low temperature as well as at room temperature and the effect of strain aging on them were studied. Materials used in this report were three kinds of (α+γ) two-phase stainless steels containing 25% Cr and, 4, 7 and 10% Ni. Specimens which were annealed mainly at 900°C were studied and the principal results were as follows. (1) Shape of the stress-strain diagrams at room temperature is identical to that of common materials without yield point. However, at −196°C a phenomenon similar to the so-called yield point can be observed after a few percent deformation in the 4 and 7% Ni specimens, containing 40 and 50% γ phase, respectively. (2) This phenomenon can also be observed in both specimens annealed at 1000°C, but disappears as the annealing temperature rises to 1100°C. It becomes obscure as the testing temperature decreases to −78°C. (3) Strain hardening rate during the uniform plastic deformation of the specimens with 4 and 7%Ni, especially 4% Ni, at −196°C is very large for a wide range of strain and this is also found to occur at −78°C. However, uniform elongations at −196°C are as large as those at room temperature in all cases. (4) In the specimens with 7% Ni, as the amount of predeformation by tension at −196°C increases the tensile strength at room temperature increases greatly. (5) Strain aging appears in every specimen and its extent becomes more prominent as the Ni content decreases and the a phase increases. (6) The above-mentioned yield point phenomenon, the increase in strain hardening rate and the increase in tensile strength by predeformation are all due to the formation of the deformation-induced martensite from the γ phase. On the other hand, the a phase plays an important role in the strain aging.抄録全体を表示PDF形式でダウンロード (811K) -
鈴木 敏之, 増本 剛1973 年 37 巻 1 号 p. 39-43
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーIn order to clarify the precipitation and its hardening effect, and the relation between aging temperature and composition of precipitates in Ni-rich NiTi, the changes in hardness and microstructure with aging temperature and time have been examined. The composition of precipitates has also been determined by an electron probe microanalyser.
In the solution treatment of Ni-rich NiTi, the higher the cooling rate the higher becomes the hardness. A significant hardening effect is obtained even by air cooling. The hardness of water-quenched specimens decreases with aging time in the temperature range from 400 to 700°C. No hardness peak is detected at these temperatures. Optical microstructure experiment shows that no precipitates exist in the water-quenched specimens, but the precipitates appear after aging for 1 to 10 hr at 600°C or 0.1 to 1 hr at 700°C. The compositions of the precipitates determined in the specimens aged at 600 and 700°C are close to Ni3Ti2 and Ni3Ti, respectively.
The above results indicate that the quench-hardening is caused by quenched-in substitutional defects and that although age-hardening occurs the hardness peak does not appear because the hardening effect is cancelled by lowering of quench-hardening as the number of substitutional defects decreases.抄録全体を表示PDF形式でダウンロード (1415K) -
大竹 周一, 本橋 嘉信1973 年 37 巻 1 号 p. 44-51
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーStress-strain curves, slip lines of the crystal surfaces and dislocation etch-pit distribution before and after deformation were studied on bismuth single crystals oriented for the (111)[10\bar1] primary glide and deformed in tension at room temperature.
The principal results obtained are as follows. (1) Stress-strain curves are divided into three stages. The work-hardening parameters have the orientation dependence, and their values are 3∼8×10−4 G, 1∼3×10−3 G and 4∼6×10−4 G for the first, second and third stages, respectively. (2) In the first stage, it is observed that single slip bands of the (111)[10\bar1] primary glide are formed, and that both edge and screw dislocations are distributed at random. (3) In the second stage, the deformation bands formed by the polygonization of the edge dislocations are observed, and the dense parts of dislocations which are distributed at random are also observed. (4) In the third stage, in addition to the (111)[10\bar1] glide in the matrix crystals, the (111)[01\bar1] glide is partly observed in the specimen oriented near ⟨11\bar2⟩, and the secondary glide systems are active in the whole crystals.
These results are discussed compared with those observed on fcc and hcp metals.抄録全体を表示PDF形式でダウンロード (1660K) -
野原 清彦, 平野 賢一1973 年 37 巻 1 号 p. 51-61
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーThe self-diffusivities of iron and manganese, DFe* and DMn*, in Fe-Mn alloys containing from 1.04 to 33.98 at% Mn were determined in the γ phase (FCC) region at 990∼1240°C by the residual activity method. At the same time, the interdiffusion coefficients, \Tilde{D}, were determined by the Matano method in the temperature range between 850 and 1300°C, using diffusion couples of pure iron and 33.98 at% Mn alloy.
It was shown that DFe* is smaller than DMn* in the experimental concentration and temperature ranges. The Kirkendall markers in the interdiffusion couple were found to move towards the higher Mn-concentration side. The intrinsic diffusion coefficients, DFe and DMn, for the composition in the vicinity of 24 at% Mn were calculated, and it was also shown that DFe is smaller than DMn.
The values of \Tilde{D} for 1177°C calculated using the experimental values of DFe*, DMn* and the activity coefficients applying Darken’s equation were shown to be in fairy good agreement with the experimental values of \Tilde{D} in the composition range lower than 20 at% Mn. Moreover, for \Tilde{D} in the composition range higher than 20 at% Mn, a better agreement between them was also obtained taking into account the effect of vacancy flow.
For each concentration, the activation energy for self-diffusion of iron, QFe* was shown to be larger than that of manganese, QMn*, and it was found that QMn*<\Tilde{Q}<QFe* in the whole concentration, where \Tilde{Q} is the apparent activation energy for interdiffusion. QFe*, QMn* and \Tilde{Q} showed the minimum value at the respective compositions lower than 10 at% Mn. The calculated values of QFe* and QMn* using the empirical equation proposed by Toth et al. were in good agreement with the observed values. The apparent activation energy for interdiffusion \Tilde{Q}, was considered as the total of three components: temperature dependence of thermodynamic factor, temperature dependence of the effect of vacancy flow, and temperature dependence of DFe* and DMn*. It was shown that the vacancy flow produced an effect which decreased the calculated value of \Tilde{D} in the whole range of composition.
The activation entropy ΔS* for self-diffusion which was calculated from the experimental values of the frequency factor D0*, was shown to be expressed by ΔS*=α(Q*⁄Tm)+ΔS0, where Tm is the melting temperature, ΔS0 is a negative term of the activation entropy which arises from the altered vibrational frequencies of the atoms constituting the saddle point configration, and α is a constant.抄録全体を表示PDF形式でダウンロード (968K) -
辻本 得蔵, 斎藤 一男, 橋本 健紀1973 年 37 巻 1 号 p. 61-67
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーThe decomposition process of Cu-4% Ti alloy during the isothermal aging at relatively low temperatures, 200∼260°C, has been studied by means of X-ray small-angle scattering technique. From the analyses of the data of the integrated scattered intensity and the application of Porod’s law, it is suggested that spinodal decomposition takes place in the early stages of aging of this alloy and that sinusoidal composition fluctuations are produced in the alloy. The determination of the values of the amplification factor demonstrates that the kinetics of the decomposition is well in accord with Cahn’s theory of spinodal decomposition. At the later stages of the aging, the sinusoidal composition wave is considered to transform into a step-like one with well-defined interface between matrix and solute-enriched regions. The critical temperature, below which the alloy is allowed to decompose spinodally, is estimated to be about 350°C.抄録全体を表示PDF形式でダウンロード (602K) -
辻本 得蔵, 橋本 健紀, 斎藤 一男1973 年 37 巻 1 号 p. 67-72
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーAging processes of Cu-4% Ti alloy after the stages of spinodal decomposition and for the stages of the formation of side-bands have been studied by means of small-angle scattering of X-rays. The scattered intensities observed for the both stages of aging can be explained by the existence of particles, i.e. square-wave concentration distribution, and not by the existence of sinusoidal concentration fluctuation due to spinodal decomposition of the alloy. Scattered intensities for the specimens accompanying side-bands are analyzed on the assumption of the formation of zone-complex. The size of the inner zone of the zone-complex increases in proportion to a logarithm of aging time. The formation of zone-complex is almost completed after 1 min aging at 350 and 400°C, and thereafter the coagulation of zone-complex is a main process of the aging. On aging at 450°C, the amount of precipitate increases with the decrease of the solute concentration in the matrix.抄録全体を表示PDF形式でダウンロード (508K) -
諸住 正太郎1973 年 37 巻 1 号 p. 72-81
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーCast-billet extruded SR and CR grade beryllium were warm-swaged at about 550°C and annealed mainly at 700 to 800°C. Then they were tensile-tested at 25 to 550°C. The results obtained are as follows:
(1) Ultimate tensile strength (UTS), 0.2% proof stress (PS) and percent elongation (E) at 25°C are propotional to d−1⁄2, where d is the average grain size in units of mm. UTS and PS at 300 to 550°C are also propotional to d−1⁄2. In the case of PS, however, values of d should be corrected with those of subgrains instead of those of normal grain size measured by optical microscopy.
(2) Each of true stress (σ)-true plastic strain (εp) curves is divided into three stages: The first is associated with the yield point phenomenon. Second and third stages are expressed by equation σ=σ0+Kεpm, where σ0, K and m are constants. The value of m in second stage is about 0.6 at 25°C and about 0.3 at 200 to 500°C. The value of K in the stage decreases with increase in temperature.
(3) The yield point phenomenon is most clearly observed in the SR annealed at 750°C and stretched at 500°C, whose structure consists of fine subgrains. It is deduced that this structure is a major factor contributory to the phenomenon.
(4) At 25 to 200°C, most fractures are brittle fractures. River pattern, twin formation and separation at grain boundary are observed in the fractured surfaces. At elevated temperatures, however, void formation at triple points of grain boundaries prevails and is frequently associated with transcrystalline cracks. Connection of voids leads the specimen to fracture and well-developed dimples of the order of grain size are observed at the fractured surface.抄録全体を表示PDF形式でダウンロード (1519K) -
新宮 秀夫, 大槻 徴, 尾崎 良平1973 年 37 巻 1 号 p. 82-87
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーThe relation between lamellar spacing λ and growth rate v has been studied from the energetic considerations for the lamellar eutectic growth. Three free energy sinks were considered; namely, the kinetic process for solidification, diffusion and solid phase boundary formation. The free energy for the kinetic process was estimated to be less than that for the formation of phase boundary. The free energy necessary for the diffusion process can be calculated by the use of the principle of irreversible thermodynamics. By obtaining the λ value which minimizes the rate of free energy supply necessary for the growth of lamellar structure, the relation λ2v=const. is given for the case where the diffusion occurs in the liquid, and λ3v=const. for the case where the diftusion is restricted in the boundary layer between solid and liquid. The constants in these relations are less complicated than those obtained by other methods and are advantageous for the numerical calculations based on them.抄録全体を表示PDF形式でダウンロード (519K) -
堀 茂徳, 佐治 余興, 大谷 三郎, 村瀬 光俊1973 年 37 巻 1 号 p. 88-93
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーThe effect of prestraining by tension on the brittleness of electron beam melted pure molybdenum was studied and the following conclusions were obtained:
(1) The brittleness of the recrystallized pure molybdenum sheets can be improved considerablly below room temperature by prestraining about 5∼10% in the ductile range. The effect of prestraining increases with the amount of prestrain and changes with the temperature at which prestrain was given.
(2) The prestrained specimens containing many edge dislocations show better ductility at low temperature than the prestrained specimens containing many screw dislocations.
(3) Strain ageing due to interstitial impurities is negligible below 300°C.
(4) As an important mechanisum, free dislocations and some Frank-Read sources introduced by the prestraining release the stress concentration when the prestrained specimens were tensile-tested at lower temperature, and the brittleness can be improved.
(5) Ageing at 500°C after prestraining at 300°C decreases the ductility of prestrained specimens at low temperature. This is due to the dislocation locking caused by the interstitial impurities.抄録全体を表示PDF形式でダウンロード (763K) -
大沢 直1973 年 37 巻 1 号 p. 94-99
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーIt is indispensable for the aluminium joint by soldering or brazing to remove the oxide film from base metal with a caustic flux. The process of oxide removal in aluminium brazing has been studied in terms of changes in the electrochemical potential of a cell set up between the oxide-coated aluminium plate and platinum in molten brazing flux. Measurements of the potential of the oxide-coated aluminium during the course of the fluxing action show that the rate of potential change is related to the flux efficiency. In this experiment the effects of fluoride addition to the LiCl-KCl system brazing flux on the fluxing action were examined.
Joining aluminium by reaction soldering also has been carried out to apply a replacement reaction between aluminium base metal and metal chlorides such as zinc-, cadmium- stanous- and lead-chlorides in molten flux. The results obtained are as follows:
(1) The flux efficiency was affected by kinds and contents of fluoride added to the LiCl-KCl base flux. Additions of alkaline and alkaline earth metal fluorides to the LiCl-KCl base flux make the flux efficiency higher than aluminium fluoride and cryorite.
(2) The oxide films are nearly completely removed from the aluminium base metal by dipping for 4 sec in the flux containing 3% sodium fluoride.
(3) The metal deposition on the aluminium base metal from the molten flux containing metal chloride is influenced by the reaction temperature and the concentration of metal chlorides. The metals deposited on the aluminium base metal flow rapidly as the filler metal to form fillets when the reaction temperature is higher than the melting points of deposited metals.
(4) The molten deposited metals of high flowability are zinc and tin, and flow factors of these metals indicating brazability, the ratio of the volume of the deposited metal to the volume of formed fillets, are larger than 1.0 at higher temperature. In case cadmium and lead which can hardly be alloyed with aluminium as the deposited metals, however, the flow factors are smaller than 1.0 usually.抄録全体を表示PDF形式でダウンロード (471K) -
尾崎 誠, 小畑 直巳, 桐原 朝夫1973 年 37 巻 1 号 p. 100-103
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーThe partial molar free energies of thorium in ThC-UC solid solutions were measured from 700 to 950°C by means of the solid state galvanic cells of the type Th, ThF4/CaF2/ThF4, Th1−xUxC. The following results were obtained:
(1) The partial molar free energy of thorium in ThC-UC solid solution increases negatively with decreasing thorium content, and the absolute value of partial molar entropy of thorium shows the maximum near Th0.5U0.5C. (2) As the ThC-UC solid solution is assumed to be a quasi-binary system of thorium and uranium, the partial molar free energy of uranium was calculated from that of thorium, and the free energy of mixing was estimated. (3) The interaction energy between thorium and uranium in Th-U-C system was calculated according to a model of the strictly regular solution. The interaction between thorium and uranium is attractive and its temperature dependence corresponds fairly well with partial molar entropy of thorium in ThC-UC solid solution.抄録全体を表示PDF形式でダウンロード (335K) -
北田 正弘1973 年 37 巻 1 号 p. 104-109
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーThe critical current densities in magnetic fields, the superconducting transition temperature and the critical magnetic field of Nb-(55∼75 at%) Ti-(0∼2 at%) Ge alloys were measured to investigate the effect of Ge addition.
The obtained results are as follows:
(1) The critical current density of Nb-Ti-Ge alloys increases with increasing Ge concentration and saturates at about 1% Ge. The ageing time for the critical current density to attain a maximum in Nb-Ti-Ge alloys decreases with increasing Ge concentration and the most suitable ageing temperature is about 450°C.
(2) The critical current densities of Nb-Ti-Ge alloys depend on Ti concentration, and the largest critical current density is obtained at a composotion of Nb-60 Ti-1 Ge. The critical current density of Nb-60 Ti-1 Ge alloy aged at 450°C for 10 hr is 7×104 A/cm2 at 80 kOe.
(3) The superconducting transition temperature and the critical magnetic field of Nb-60 Ti-1 Ge alloy are 9.6°K and 120 kOe (4.2°K), respectively.抄録全体を表示PDF形式でダウンロード (424K) -
砂野 豊治朗, 高野 道典, 下平 三郎1973 年 37 巻 1 号 p. 110-117
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーEffects of Cr or Cu as an alloying element, heat treatment and applied stress on the grainboundary corrosion and stress corrosion cracking of Al-4.57% Zn-1.35% Mg (alloy A), Al-4.63% Zn-2.46% Mg (alloy B), Al-4.86% Zn-1.44% Mg-0.3% Cr (alloy C) and Al-4.43% Zn-1.34% Mg-0.13% Cu (alloy D) have been studied at room temperature in Keller’s solution (H2O-HCl-HNO3-HF, pH 2.58).
Deep pitting that has an acute square, pentagonal or hexagonal shape proceed along the edges of three adjacent grainboundaries (triple point pitting) in both of the alloys A and B. The triple point pitting is irregular in shape and shallow in the alloy C. The acute triple point pitting also grows in the alloy D, but is smaller and shallower than that in the alloys A and B. The triple point pitting is strongly influenced by the heat treatment and accelerated remarkably at any applied stresses. The stress corrosion cracking susceptibilities are parallel to that of the triple point pitting in Al-Zn-Mg alloys.抄録全体を表示PDF形式でダウンロード (1851K) -
有冨 敬芳1973 年 37 巻 1 号 p. 118-126
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーAs a preliminary experiment to investigate the applicability of alloy softening with platinum group metals to the ductility improvement of polycrystalline molybdenum, the effects of single additions of Ru and Pt and of complex additions of 0.15 wt% Ru and C or B on the room-temperature ductility of an electron-beam melted molybdenum ingot have been studied. The results are as follows: (1) Room-temperature hardness of the ingot was lowered by 35∼45 in Vickers hardness by the single additions of 0.1∼0.2 wt% Ru and Pt. However, these softened ingots were apt to fracture intergranularly at a low stress and displayed virtually no ductility. (2) The complex additions of 0.15 wt% Ru and a suitable amount of C or B made the ingot ductile and soft, the room-temperature hardness of which was about 30 in Vickers hardness lower than that of the unalloyed ingot. These ductile ingots could be rolled sufficiently at 1200°C as in the case of the ingots alloyed with C and B respectively, without Ru, though Ru increases the high-temperature hardness of ingot. (3) It can be concluded that alloy softening with Ru may be useful to the ductility improvement of polycrystalline molybdenum when the intergranular brittleness is suppressed.抄録全体を表示PDF形式でダウンロード (1947K) -
有冨 敬芳, 三喜田 浩1973 年 37 巻 1 号 p. 127-134
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーTo clarify the applicability of alloy softening with Ru to the ductility improvement of polycrystalline molybdenum, two kinds of recrystallized 1 mmφ wire specimens, the one alloyed with 0.14 wt% Ru and the other without it, both of which contained 0.02 wt% C, have been tested in tension. The grain size was varied from 0.013 to 0.3 mm. The testing temperatures were −76, 25 and 200°C at a strain-rate of ∼10−4 sec−1, and the strainrate was varied from ∼10−4 to ∼10−1 sec−1 at 25°C. From the differences in tensile properties between the two specimens, effects of 0.14 wt% Ru are summarized as follows: (1) The decrease in room-temperature hardness of the ingot by the addition of Ru corresponds to the decrease in yield stress, but Ru increases strain-hardening. (2) The decrease in yield stress with Ru addition is attributed to the decrease in the temperature- and strain-rate-dependence of yield stress. Ru increases the yield stress at high temperatures. (3) Ru contributes to the increase in ductility at a low temperature and high strain-rate through lowering the yield stress, whereas it decreases slightly the reduction in area at fracture when the specimen is at a high ductility level. (4) Ru increases markedly the uniform elongation and so called “working range” at room temperature. (5) In conclusion, it is expected that Ru additions give favorable effects on the some kinds of practical fabrication process at room temperature.抄録全体を表示PDF形式でダウンロード (916K) -
1973 年 37 巻 1 号 p. 134
発行日: 1973年
公開日: 2008/04/04
ジャーナル フリーPDFを参照． （誤）材料としては特殊な熱処理を加えて, （脱落）, Sij(×10−5 cm2/kg) （正）材料としては特殊な加工または熱処理を加えて, S11 , S11 and S11−S12−½S44(×10−5 cm2/kg)抄録全体を表示PDF形式でダウンロード (52K)
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