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Volume 30, Issue 6
Displaying 1-18 of 18 articles from this issue
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Masao Homma, Reiichi Ohno, Tsuneo Ishida1966 Volume 30 Issue 6 Pages 515-520
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to study the evaporation of manganese, copper and tin from molten iron, Fe-Mn, Fe-C-Mn, Fe-Cu and Fe-Sn alloys were melted at 1600°C under vacuum for 5, 10, 15 and 20 minutes by using a high frequency induction furnace. For the initial 10 or 15 minutes, the rates of loss of the alloying elements followed the first-order kinetics, and the following specific evaporation constants were obtained:
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From these values, the ratios CS⁄Cm of surface concentrations to the bulk concentrations were calculated for manganese, copper and tin according to the equations derived by Ward. The values of CS⁄Cm are as follows:
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The evaporation coefficient α and the distribution coefficient k which were derived by Olette and Fischer, respectively, were obtained experimentally, and also theoretically calculated according to their equations. In the case of Fe-Mn and Fe-Cu alloys, the theoretical value of α is greater than the experimental one. Generally in the melting for 5 minutes, the theoretical value of k is smaller than the experimental one. When the ratio CS⁄Cm is introduced into the coefficients α and k, the calculated values of the evaporation coefficient and the distribution coefficient are close to the experimental values.View full abstractDownload PDF (1442K) -
Kiyoshi Takayanagi, Natoshi Takezaki, Akira Negishi1966 Volume 30 Issue 6 Pages 521-527
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFactors affecting variations of properties of sintered thermoelements have been discovered and their effects investigated.
It is thought that many correlative factors affect the thermoelectric properties of sintered thermoelements. First, eight factors were taken into consideration from which five effective factors were selected by the statistical method. Then, their effects on specific resistivity ρ, thermoelectric power α, and α2⁄ρ were investigated for specimens of the N-type Bi2Te3 doped with AgI. The results obtained are as follows: The values of ρ and |α| of elements from the powder produced in air are lower than in nitrogen. As the time required for the powder production and the holding time of green compacts becomes longer, both ρ and |α| decrease. These results show that as the production process becomes more advantageous for the powder oxidation, ρ and |α| in the sintered elements decrease. Consequently, the oxidation of the powder is thought to be the main cause of the property variations in the sintered elements.View full abstractDownload PDF (2225K) -
Kiyoshi Takayanagi, Natoshi Takezaki, Akira Negishi1966 Volume 30 Issue 6 Pages 527-533
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of factors relating to powder oxidation of sintered Bi2Te3 thermoelements (N type) and the mechanism of the oxidation have been studied. First, the factors which seem to affect the powder oxidation were picked up by a statistical design method and their effects on the specific resistivity ρ, thermoelectric power α and α2⁄ρ were investigated by means of variation analysis. Then, the effects of the factors great in influence were exarained in detail in connection with the effect of the interval between powder production and sintering.
As a result of the experiment, it was made clear that the effects of the humidity and temperature during the powder production and of the particle size were remarkable.
The higher the humidity and temperature and the smaller the particle size, the lower the specific resistivity. Besides, the thermoelectric power and specific resistivity of the sintered elements decreased with the interval between powder production and sintering, but the lower the temperature and humidity during powder production, the more remarkable the tendency of decrease. The decreases in specific resistivity and thermoelectric power of sintered elements due to the powder oxidation was thought to be the donor operation of oxygen atoms occupying Te atom sites in the Bi2Te3 crystal. From the time dependence of electron concentration in the green compacts it was clarified that the increase in the electron concentration occourred during sintering.View full abstractDownload PDF (1891K) -
Masayoshi Hasegawa, Masafumi Okamoto1966 Volume 30 Issue 6 Pages 533-540
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to find the properties of the ternary alloys of iron and boron containing Si, Ti, V, Cr, Mn, Ni, Zr, Nb, Mo and W free from carbon, investigation have been made on the peritectoid reaction, microstructure, hardness, tempering properties, hardenability and mechanical properties. The boron contents in the specimens were 0.02% and 0.20%, and the alloying elements were added in consideration of the stoichimetric metal/boron ratio. The results are summerized as follows:
(1) Zr, Ti, Mo and Nb rose the peritectoid reaction temperature of Fe-B alloy, but Cr, Ni and Mn lowered it.
(2) In the Fe-B ternary alloys solution-quenched, the aciccular structure consisting of body-centered cubic appeared, and the fomation of this structure was closely related to the cooling rate and the alloying element.
(3) Si, Ni, Mn and Cr had a weak tendency to form alloy boride (special boride) and mainly formed iron boride, but Ti, Zr, Nb, Mo and W had a strong tendency to form alloy boride.
(4) W, Nb, Mo, Ti and Zr forming the fine-distributed alloy boride markedly increased the hardness of the Fe-B alloy annealed and solution-quenched.
(5) In the tempering of Fe-B ternary alloys after water-quenched from 1100°C, a secondary hardening associated with the precipitation of iron boride or alloy boride was found. In the specimens alloyed with Ni, Si and Cr, the peak hardness was developed at 100° to 200°C, but at 450° to 600°C in cases of Nb, Mo and W.
(6) W, Nb, Mn and Mo markedly increased the tensile strength of Fe-B alloys air-cooled and water-quenched at room temperature, but deteriorated their ductility and toughness.View full abstractDownload PDF (3403K) -
Michitomo Kato1966 Volume 30 Issue 6 Pages 540-546
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSGrain boundary sliding and migration at various constant temperatures under constant shear load were observed in high-purity aluminium bicrystals with the boundary misorientation angles of 4°58′ and 32°13′. The bicrystal specimen was prepared by the Bridgeman method. The constant temperature shear test was carried out in the temperature range from 250° to 400°C.
The grain boundary sliding versus time curve changes stepwise in the constant load test, i.e., the active boundary sliding period and boundary migration period (horizontal part of the curve) proceeded alternately. Grain boundary sliding was observed to take place accompanied by the localized deformation in a region adjacent to grain boundary. The contribution of grain boundary sliding to the deformation amount of the specimen became smaller with the test time, and the maximum value was found to be about 34% at 400°C for 100 minutes. A plot of the logarithm of the amount of grain boundary sliding per second versus the reciprocal of the absolute temperature resulted in a series of straight lines. The activation energies for grain boundary sliding which were calculated from the slope of the straight lines were 10200 cal/mol in the case of the misorientation angle of 32°13′, and 8600 cal/mol in the case of 4°58′, respectively.View full abstractDownload PDF (1853K) -
Michitomo Kato1966 Volume 30 Issue 6 Pages 546-551
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe behavior of grain boundary during the deformation by shear at a constant load and temperature was studied by the use of bicrystal specimens of Al-0.2∼0.5%Cu alloy. The alloy used is a solid solution at the test temperatures. The bicrystal specimens with the boundary misorientation angle of 33°06′∼34°16′ have been prepared by Bridgemann method. The experimental results are summarized as follows. (1) The addition of 0.2%Cu greatly affected the grain boundary sliding of pure Al, but the addition of 0.2∼0.5% Cu did not. (2) Grain boundary sliding versus time curves showed a tendency to show wavy variation after a linear change in the first stage, and this tendency was weakened with increase of the Cu content. (3) The contribution of grain boundary sliding to the deformation amount of the specimen became smaller with increase of the solute atom, and its maximum value of Al-0.2%Cu alloy was found to be about 16% at 400°C for 100 minutes. (4) A plot of the logarithm of the amount of grain boundary sliding per second versus the reciprocal of absolute temperature resulted in a series of straight lines. The activation energy for grain boundary sliding was calculated from the slope of those lines.View full abstractDownload PDF (2304K) -
Tetsuro Ishizaka, Keizo Yamabe, Toshio Takahashi1966 Volume 30 Issue 6 Pages 552-558
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt is well known that in silicon-iron alloy about 6.5% silicon-iron alloys has the highest permeability but the alloys containing above 5% silicon are very hard and brittle, and cannot be cold-rolled. Therefore, to prepare thin plates, the has warm-rolling method been employed. To enable the alloys containing up to about 6.5% silicon to be cold-rolled, the authors investigated the effects of hot-rolling conditions on the cold workability of these alloys.
The samples were melted by the high frequency furnace in open atomsphere and hot-rolled in various conditions and the mechanical properties and cold workability were measured. After hot-rolling at 1000°C, the tensile strength and elongation fell rapidly above 5% and 4.5% silicon respectively, but when the rolling temperatures were lower the peak of strength sifted to the higher silicon side and the elongation of the higher silicon alloys increased. The tensile strength of the 6.45% silicon alloy, hot-rolled by 91% at 750°C, was 120 kg/mm2 and the elongation was 1%, and by the bending test some ductility was observed in the rolling direction. This is because the crystal grains were elongated in the rolling direction by the hot-rolling. Thus the alloys containing up to about 6.5% silicon could be cold-rolled from 1 mm to less than 0.3 mm by the hot-rolling above 70% at 600°∼750°C and the slitting of the side edges.
Magnetic properties of the 0.3 mm thick 6.45% silicon alloy were as follows: The initial permeability μ0=1460, the maximum permeability μm=22500, the coercive force Hc=0.15 Oe and the watt loss W10⁄50=0.58 watt/kg.View full abstractDownload PDF (2152K) -
Kaizo Monma, Hajime Suto1966 Volume 30 Issue 6 Pages 558-562
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn a previous paper, it has been pointed out experimentally that the role of interaction between dislocations and “I.S.” atmosphere is very important for the high temperature strength of low alloy steels. The “I.S.” atmosphere named by the authors is the atmosphere of the complex of interstitial atoms (I) and substitutional atoms (S) combined chemically to each other. In this paper, the dragging force due to various solute atmospheres is calculated with Cottrell’s equations. It is concluded that the dragging force due to “I.S.” atmosphere in the iron-2% chromium alloy is about 4 kg/mm2 at a creep rate of 0.01%/hr at 800°K.View full abstractDownload PDF (1744K) -
Ryoichi Nozato1966 Volume 30 Issue 6 Pages 563-568
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe specific heat vs. temperature curves were obtained during the re-heating of the lead-0.4 wt%Mg alloys aged for various times at the ageing temperature (room temperature, 50° and 100°C). The shapes of the specific heat vs. temperature curves obtained in this experiment were discussed, and the amounts of heat evolution and heat absorption observed on the specific heat vs. temperature curves were plotted as a function of the ageing time prior to specific heat measurements. (1) The heat evolution and the heat absorption, which were observed at 80°∼180°C and 180°∼225°C respectively on the specific heat vs. temperature curve of the alloy aged at 100°C (a high ageing temperature), were interpreted respectively as accompanying the formation of the stable precipitate Mg2Pb and the re-dissolution of its precipitate into matrix lead. (2) An additional heat absorption followed by the heat evolution accompanying the formation of the stable precipitate was observed at about 110C° on the specific heat vs. temperature curves of the alloy aged at low ageing temperatures (below 50°C). This additional heat absorption could be explained due to the “reversion phenomena” (the dispersion of G-P zone into matrix lead). (3) An irregularity in the valley of the heat evolution accompanying the formation of the stable precipitate was observed at about 110°C on the specific heat vs. temperature curve of the alloy aged 10∼70 hr at room temperature. This irregularity was also considered due to the reversion phenomena. (4) The fractional change (f) of precipitation heat with ageing time (t) at 100°C seemed to be represented Johnson-Mehl’s equation: f=1−exp(−btn), where b and n are the constants. The value of n was about 2.5.View full abstractDownload PDF (1684K) -
Katsuya Watanabe, Shigeyasu Koda1966 Volume 30 Issue 6 Pages 568-574
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDislocation lines in the θ phase which coexisted with aluminum were observed by transmission electron microscope. In the annealed state, tangled dislocations were high in density in aluminum grains, whereas their density was very low in the θ phase. Dislocation lines in the θ phase were nearly straight. This means a high Peierls-Nabarro force for the motion of dislocations in the θ phase. When the specimen was compressed below the deformation temperature of about 400°C, the dislocations in the θ phase were multiplicated but restricted on the glide planes. Above the temperature, when compressed, the multiplicated dislocations became possible to climb and formed a network structure. Also at a high temperature and a high density of dislocations, aluminum precipitated along ⟨110⟩ directions of the network structure in the θ phase. The relation between the deformation temperature and the apparant yield stress for the compression of the θ phase showed that the θ phase becomes plastic above 400°C. The result was consistent with the electron microscopic observations. The {310} plane was considered the most probable glide plane of the θ phase in view of the atomic positions of Cu and Al in the lattice of the θ phase and also of the directions of dislocation arrays determined by the electron diffraction patterns.View full abstractDownload PDF (2231K) -
Juzo Shirogane, Yoshinori Onodera, Masakazu Fukai1966 Volume 30 Issue 6 Pages 574-579
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy the chemical transport reaction of iodine, the growth of the ZnSe single crystal was studied. The optimum conditions for the growth were found to be: the evaporation temperature, 1025°C; the crystallization temperature, 825°C; the iodine content, 5.5 mg/cm3. The dimensions of the single crystal were 5×5×2 mm.
The as-grown crystal has a cubic structure, a lattice constant of 5.66 Å, and a high etch pit density. The single crystal was found to contain about 180 ppm iodine by mass spectrography. The resistivity of the as-grown crystal was about 106∼107 Ω-cm. This result suggests that iodine in the single crystal acts as donor at a relatively deep level or isolated as molecule or separate phase. The heat treatment in molten Zn reduced the initial high resistivity to a few Ω-cm.View full abstractDownload PDF (1859K) -
Kenzaburô Kumada1966 Volume 30 Issue 6 Pages 579-584
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effect of nickel on the sigma transformation in Fe-45%Cr alloys, was studied by dilatometric, magnetic measurements and microscopic observations. Specimens were transformed into the sigma phase in the temperature range from 650°∼800°C for various periods of time. It was established that the rate of the sigma transformation in Fe-Cr alloys and the expansion coefficient of sigma increase with the increase of the nickel content up to 4%. Some effects of nickel on physical and mechanical properties of ferrite of Fe-Cr alloys were also studied.View full abstractDownload PDF (1496K) -
Tatsuro Kunitake1966 Volume 30 Issue 6 Pages 585-590
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of various factors on the concentrating process of carbide forming elements into cementite during the tempering of low-alloy steels have been investigated. The experimental results on the effect of the austenitizing temperature, the initial microstructures prior to tempering and the carbon contents of steels on the reaction are compared with the theoretical expectations. It is shown that the effects of these variables can be explained on the basis of the proposed diffusion-in-ferrite controlling model.View full abstractDownload PDF (1912K) -
Isao Gokyu, Keijiro Suzuki, Hirokazu Tanabe, Kiichi Akasaka1966 Volume 30 Issue 6 Pages 591-596
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSInvestigations have been made on the relationships among the texture, r-value and work hardening exponent n for various tensile directions, grain size and press formability of 2S aluminium and copper. Correlation between the conical cup value and the texture has been obtained. The growth of the cube texture lowers press formability involving drawing and stretch forming simultaneously. However, the difference between Al and Cu cannot be explaind by the texture. Copper, of which the (100)[001] component is stronger than that of aluminium, has much better formability, probably due to the higher work hardening exponent of Cu.
On the other hand, good conformity is shown between the conical cup value and the average value (\barr) or the r-value in the 45° direction. Particularly “r45°” which follows variations of the (100)[001] or (112)[111] component seems to indicate deep drawability of f.c.c. metals which contain (100)[001] as one of the main texture components.
There is a direct relationship between the Erichsen cupping value and the mean work hardening exponent \barn which increases not only with the grain size but with the cube texture. It has been noticed that the cube texture may be desirable for stretch forming, although in such a deformation the work hardening of the textured sheets may be different from that under uniaxial stress.View full abstractDownload PDF (1952K) -
Isao Gokyu, Keijiro Suzuki, Hirokazu Tanabe1966 Volume 30 Issue 6 Pages 597-603
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMany investigations have been made on the earing phenomenon of deep-drawn cup. In predicting the relationship between texture and earing, caluculations have been carried out on the assumption that only the circumferential compressional stress is effective for the development of ears. Assuming as a first approximation that the radial and circumferential stresses equal in magnitude are uniformly distributed in the blank. Tucker has obtained good agreement between the predicted and experimentally measured values for cups pressed from aluminum single crystals.
To clarify the reason of such a good agreement in spite of the unrealistic assumption of such an overall uniform stress field, strain measurments during deep-drawing have been made on the blank of the cubically oriented copper sheet. From the measurment of strain variations in the blank during the deep-drawing operation, validity of Tucker’s assumption can be explained. In this deep-drawing process, fractures are observed to initiate in the parallel and perpendiclar directions to the rolling direction where the r-values are maximum and the elongation to fracture is minimum.View full abstractDownload PDF (1769K) -
Akiyoshi Miyoshi, Kôichi Hino, Akio Hara, Sueno Kurata1966 Volume 30 Issue 6 Pages 603-606
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe Co phase contained in cemented carbides is not pure cobalt but a Co solid solution which sometimes contains metallic elements more than 10%. With a decrease in carbon content, the amount of dissolved elements increases. In the case of the WC-Co cemented carbide, the dissolved element is only W and the amount can be obtained by measuring the lattice parameter of the Co phase. However, it is impossible for the cemented carbide containing TiC, TaC or NbC. In this paper the quantitative analytical method and the results for various cemented carbides are described. When the crushed particles are heated in a HCl aqueous solution, only the Co phase will be leached. The leached solution has been chemically analysed to measure W and Ti contents. The W content obtained by this method coincides well with the one by measuring the lattice parameter of the Co phase. It is concluded that Ti, Ta and Nb rarely dissolve into the Co phase in the composition range where the WC phase exists in the microstructure of the cemented carbide.View full abstractDownload PDF (1253K) -
Hideo Sugawara, Saburo Shimodaira1966 Volume 30 Issue 6 Pages 607-612
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSPotentiodynamic measurements of anodic and cathodic polarization curves of copper, nickel, aluminium, brass (30%Zn), cupronickel (30%Ni) and aluminium brass (2%Al) were carried out in stagnant and moving 3%NaCl aqueous solutions containing hydrogen sulfide of 10 ppm. Anodic and cathodic reactions of these copper alloys in 3%NaCl aqueous solutions were both strongly accelerated by the coexistence of hydrogen sulfide and dissolved oxygen. Anodic films on copper alloys easily broke away in moving solutions. The surface films formed on these metals and alloys in a 3%NaCl solution were found, by electron diffraction method, to be mainly composed of Cu2O, and in the case of the 3%NaCl aqueous solution containing hydrogen sulfide, to be a certain substance of unknown structure. This substance is considered to be a kind of sulfide. The resistance of copper alloys against corrosion of the type of cathodic control in the 3%NaCl aqueous solution containing hydrogen sulfide can be put in the following order judging from the electrochemical polarization characteristics; cupronickel>aluminium brass\gtrsimbrass>copper in anodic controlled corrosion and aluminium brass\gtrsimbrass>copper>cupronickel.View full abstractDownload PDF (1357K) -
Harue Wada, Koki Gunji, Tsuguyasu Wada1966 Volume 30 Issue 6 Pages 613-616
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA method is shown for calculating the difference between the interaction parameters in liquid iron alloy and those in γ-iron alloy from the binary phase diagram or other thermodynamic knowledge using a regular solution model. The difference ΔεY(X) for a substitutional-interstitial Fe-X-Y alloy is given by either of the following equations.
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\ oindentwhere X and C, N are a substitutional and interstitial components, respectively. ΔSX and ΔSFe are the entropy of fusion for each component, (dxC⁄dT) is the slope of the allotropic phase boundary of each binary alloy, and xCγ, xCl arethe mole fraction of C in the γ- and the liquid phase, respectively.
Using these equations, the differences between liquid and γ-iron ΔεC(Co), ΔεC(Ni), ΔεC(Mn), ΔεN(Cr), ΔεN(Mn) are estimated as −0.10, −0.31, 0.79, −1.3 and 2.2, respectively, which are in reasonable agreement with the experimental values, 0.6, −0.26, 1.8, −2.0 and 1.3, respectively.View full abstractDownload PDF (1299K)
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