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Volume 30, Issue 7
Displaying 1-19 of 19 articles from this issue
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Kazutaka Sakiyama, Masami Fujimoto1966 Volume 30 Issue 7 Pages 617-622
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe corrosion tests on stainless steels in about 47% caustic soda solutions containing a varying amount of NaClO3 at 90°C were carried out in order to find the effects of ClO3− ion. The results obtained are summerized as follows. (1) The corrosion rate of mild steel is found to increase very severely by cathodic depolarization when the NaClO3 content is 1% or less, while when the content increases up to 1.5%, corrosion decreases abruptly due to anodic passivation, and when the concentration exceeds 1.5%, the corrosion rate increases gradually. (2) Cast iron shows the same corrosion behaviors as mild steel. But the maximum corrosion rate of cast iron is markedly smaller than that of mild steel. (3) The corrosion rate of chromium-type stainless steels is smaller as the NaClO3 content increases. (4) Austenic stainless steel has excellent corrosion resistance in caustic soda solutions containing NaClO3. We must, however, pay attention to the deterioration effects of the molybdenium content which is added to the alloy.View full abstractDownload PDF (1226K) -
Hideo Saitô, Yutaka Sugai1966 Volume 30 Issue 7 Pages 622-626
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe magnetization and the magnetic anisotropy were measured at room temperature after the annealing at various temperatures with a ferromagnetic γ-phase alloy containing 27 per cent of cobalt, 9 per cent of chromium, 17 per cent of nickel and the rest of iron, which was colled rolled in the reduction more than 50 per cent. It was found that the positive uniaxial anisotropy constant induced by colled rolling changed its sign after the treatment at the temperatures from 300° to 500°C; the negative maximum value was obtained after the treatment made at the temperatures from 550° to 600°C, accompanying the appearance of a negative crystal anisotropy constants. The change of magnetization curves by the treatment was also in parallel with that of the uniaxial anisotropy constant mentioned above. These results were explained clearly by the formation of twins and the aggregation of some elements into the slip planes.View full abstractDownload PDF (1471K) -
Hideo Sugawara, Saburo Shimodaira1966 Volume 30 Issue 7 Pages 626-630
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe anodic behavior of copper in air-saturated NaCl aqueous solutions has been studied by both galvanostatic and potentiodynamic methods to determine the effects of the Cl− ion concentration and temperature on the dissolution of copper. The polarization curves of copper represents the two active-passive transitions. In a less noble electrode potential region, a CuCl layer was formed on copper. It was then transformed into Cu2O by the reaction with H2O and the first passivation occurred. The potential of the CuCl formation in the strong chloride solution was less noble than that in the dilute chloride solution. In an intermediate potential region, the second passivation begins when the reaction is proceeded between Cl− ion and CuCl to form Cu2O. Although CuCl is not direct cause of the passivation of copper, a stable region of Cu2O extends due to decreasing Cl− ion concentration in the electrode-solution interface by the formation of CuCl. To help interpretation of the polarization curves, a potential-pH diagram of the Cu-Cl-H2O system has shown the domains of the stable solid phase in 0.3 to 30%NaCl aqueous solutions.View full abstractDownload PDF (1607K) -
Hideo Sugawara, Saburo Shimodaira1966 Volume 30 Issue 7 Pages 631-635
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA potentiodynamic method was used to study the influence of various factors on the formation of films on the copper anode in air-saturated 3%NaCl aqueous solutions. The various factors were as follows: Potential sweeping rate of upward and downward scan, contamination of solutions with copper ions and soft mechanical abrasion of electrode surface. Four potential sweeping rates (1.0, 0.125, 0.04 and 0.01 V/min) were adopted. Polarization curves involving active-passive transitions were different depending on the potential sweeping rates. In a less noble potential region, the transformation from CuCl to Cu2O is relatively slower and the diffinite thickness of surface films were demanded for passivation. These films are reduced to copper at a potential below −0.09 V (S.C.E.). The concentrations of both Cl− ion and OH− ion of the solution near the electrode surface decrease with polarization, and it tends to establish the (Cu/Cu2O+CuCl/Cl−) electrode potential, resulting in the anodic dissolution of Cu2O. The surface films are removed by the soft mechanical abrasion. By the electron diffraction analysis the anode films are found to be composed of Cu2O in all anodic polarizing regions, CuCl in an intermediate potential region and CuCl including Cu in a higher potential region.View full abstractDownload PDF (1132K) -
Kimiyuki Kamino1966 Volume 30 Issue 7 Pages 636-640
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSBy the addition of Boron in the MnAl alloy, its magnetic properties are improved remarkably. This study is concerned with improvement in the magnetic properties by swaging working of some MnAl-B alloys.
The specimens, cast in vacuum, were enclosed in stainless steel pipes and heat treated before and after swaging and the processes of the treatment were studied magnetically.
The optimum condition for the heat treatment before swaging was as follows: −1100°C, 2 hr heated in Argon gas-water quenched −350°C, 2 hr tempered.
The maximum reduction rate by swaging was 70%, and the optimum tempering condition after swaging was found to be at 400°C, for 2 hr.
The maximum magnetic properties of Mn(71.0%) Al(26.65%)-B(1.76%) alloy were 5900 gauss in Br, 1780 Oe in BHC, 3.5 M·G·Oe in erergy product.
The needle-shape crystals in MnAl-B matrix act as secondary ferromagnetic phase and seem to be a Mn-B compound by means of X-ray microanalyser.View full abstractDownload PDF (800K) -
Hiroshi Kojima, Keitaro Sakai1966 Volume 30 Issue 7 Pages 640-644
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe magnetic properties of sintered Ba ferrite can be improved by adding Bi2O3. To investigate the mechanism of such improvement, X-ray anlysis and measurements of magnetic properties of Ba, Sr and Pb ferrite containning 0 to 5 mol%Bi2O3 were performed. The obtained results are as follows:
(1) When added, Bi2O3 coexists with the magnetoplumbite phase in the form of BaFeO3 in Ba and Sr ferrite, and in the form of α-Bi2O3 in Pb ferrite respectively.
(2) Curie temperature slightly decreases with Bi2O3 contents in the Ba system but it remains constant in the Sr and Pb system. Hardly any change in the lattice parameter was observed in each system.
(3) Apparent saturation magnetization decreases with the amount of Bi2O3 but the saturation of the magnetoplumbite phase shows a certain constant value for each system after correcting for the non-magnetic phases.
(4) By adding Bi2O3, the characteristics as a permanent magnet can remarkably be improved in Ba ferrite, but it affects adversely in Pb ferrite and the coercive force alone increases in some degree in Sr ferrite.
From the above experimental facts, it was confirmed that the improvement in the magnetic properties of Ba ferrite by the addition of Bi2O3 is owing to the secondary effects of acceleration in the reaction and sintering process.View full abstractDownload PDF (1177K) -
Hakaru Masumoto, Takeo Kobayashi, Kiyoshi Watanabe1966 Volume 30 Issue 7 Pages 645-649
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present investigators previously found a new magnet alloy “Malcolloy” having a high coercive force in the system of cobalt and aluminum and then have carried out studies on the influence of the addition of nickel, molybdenum and titanium on their magnetic properties; the highest coercive force obtained being 1600 Oe. Further, they have investigated the influence of the addition of vanadium on the properties of Co-Al alloys and discovered that the addition of vanadium increases the coercive force of the binary alloys. Thus, an alloy with the composition of 81.93%Co, 13.42%Al and 4.65%V shows a coercive force of 1450 Oe, a residual magnetic flux density of 3200 G, and a maximum energy product of 1.40×106 G·Oe, when tempered at 550°C for 15 hours after water-quenching from 1370°C. These alloys consist of many ferromagnetic elongated particles of about 300∼400 Å diameter which are dispersed in the matrix of almost non-magnetic β′ phase. Consequently, it may be concluded that the high coercivity of these alloys is mainly caused by the existence of the small particles, each of them being composed of a single magnetic domain.View full abstractDownload PDF (1932K) -
Katashi Masumoto, Shigehiro Isomura, Wataru Gotô1966 Volume 30 Issue 7 Pages 649-655
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDesirable crystals of ZnSiAs2, ZnGeP2 and CdGeP2 of the group of AIIBIVCV2 compounds have been grown by either vertical Bridgman method or slow cooling.
Preparation of the phosphides was carried out with an internal heating high-pressure resistance furnace. The following physical, thermal and electrical properties of these compounds were measured; the melting point, lattice constants, microhardness, Seebeck coefficient and thermal conductivity at room temperature, and the temperature dependence of resistivity and Hall coefficient.
ZnSiAs2 and ZnGeP2 are p-type and CdGeP2 is n-type. ZnSiAs2 is regarded as a material similar to the “semi-insulating” GaAs from the temperature dependence of electrical properties. It was found that the melting points of ZnSiAs2, ZnGeP2 and CdGeP2 lie at 1096°, 1025° and 800°C, respectively, and ZnGeP2 undergoes a solid state transformation at 952°C. CdGeP2 was determined to have the chalcopyrite structure with the lattice constants of a=5.740±0.001 Å and c⁄a=1.876±0.001. All the compounds show total thermal conductivities of 0.1-0.2 W/cm-deg, lower than most binary semiconductors AIIIBV. It can be said that on the AIIBIVCV2 compounds, a general linear trend such as found in the AIBIIIC2VI compounds of the same type exists between the shortest interatomic distance and the hardness or the energy gap, and between the tetragonality and the ordering factor, Δrc‾ΔX (Δrc=the differences in the ionic radii of cations, ‾ΔX=the electronegativity difference of the constituents).View full abstractDownload PDF (1905K) -
Ishi Miura, Mamoru Ôta, Hisao Honma, Etsuo Sasaki1966 Volume 30 Issue 7 Pages 655-659
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSSpecial techniques have been developed in the field of dentistry, and one of them is called “the condensation method of gold foils”. It is a technique to fill a cavity in a tooth with gold, platinum or tin foils singly or complexly. This method is considered a very unique method to make the metal composites and there is the possibility to obtain the composite with a unique and controlled structure by means of this condensation method.
In this report, the technique to realize the idea stated above has been in development using a simple model. As the mother material, i.e. the matrix, aluminum foils are selected and many other metal foils and ribbons are synthesized by means of the pressure welding or rolling process. According to the results, the dies for pressure welding of metal foils, the effect of the thickness of aluminum foils on weldability, the effect, of the pressing or rolling temperature and the sheathing method of specimens for preventing the oxidation are given. Some of the results by the tensile test of the specimens are also reported. Those results suggest a possibility for making the further complex structures with the controlled distribution of metal fibre, metal net, metallic compound, ceramics, etc.View full abstractDownload PDF (1252K) -
Ishi Miura, Etsuo Sasaki, Hisao Honma, Mamoru Ôta1966 Volume 30 Issue 7 Pages 659-662
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe creep behavior of a aluminum sheet in which very thin and cutted layers of aluminum oxide were finely lined was investigated. The aluminum sheet was made of thin aluminum foils (thickness: 7 μ and 35 μ), which were packed between thin mica plates, by hot rolling. The quantity of the aluminum oxide is estimated <0.1 wt%. Microstructures of the cross section of the specimens are shown in Photo. 1. The main results are as follows:
(1) The creep strength of aluminum are largely improved with the above type of distribution of a small quantity of aluminum oxide. (2) The creep strength of this aluminum sheet is changed with the thickness of aluminum foils used, and the foils becomes thinner with increasing. (3) The creep strength of the aluminum sheet shows an intermediate value between the creep strengths of SAP and the pure aluminum plate.View full abstractDownload PDF (1271K) -
Ishi Miura, Etsuo Sasaki1966 Volume 30 Issue 7 Pages 662-668
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe recrystallization of aluminum sheet in which very thin and fragmentary layers of aluminum oxide were finely lined was studied. This aluminum sheet was made of thin aluminum foils (thickness: 7, 11, 25, 50 and 100 μ), which were packed between thin mica plates, by hot rolling. Durring hot rolling, aluminum foils were bonded together, and formed the layers on the original boundary between the aluminum foils. Photomicrographs of the cross section of specimens are shown in Photos. 1 and 2.
The main result are as follows:
(1) The above type of distribution of a small quantity of aluminum oxide in aluminum has an effect to shift the recrystallization of aluminum to a higher temperature than that of aluminum which is used as a material.
(2) The shift of recrystallization temperature is greater as the thickness of the aluminum foil is smaller and the cold rolling reduction lowers.View full abstractDownload PDF (2708K) -
Isao Gokyu, Keijiro Suzuki, Mitoshi Tominaga1966 Volume 30 Issue 7 Pages 669-673
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of soaking and hot rolling temperatures were studied on the recrystallization texture, strain ratio (r-value), earing and formability of annealed commercial purity aluminium sheets. The following results were observed.
(1) Texture, r values, earing and formability of annealed sheets were not changed by the hot rolling temperature. However, the effect of the soaking temperature was remarkable.
(2) The annealed aluminium sheets, which were soaked at 500°C or 560°C, had many (224) planes parallel to the specimen surface. This specimen showed high r values in the 45° direction, good drawability and high 45°-earing.
(3) When soaked at 420°C or 600°C, the X-ray reflection intensity from (224) planes parallel to the specimen surface became weak and r values in the 45° direction decreased. This specimen showed unsatisfactory drawability and low 45°-earing.View full abstractDownload PDF (1277K) -
Yoshimoto Wanibe, Kôkichi Sano1966 Volume 30 Issue 7 Pages 674-678
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present work was carried out to obtain the knowledge of the formation of inclusions when liquid iron was deoxidized by aluminium. An alumina tube, 6 mm in i.d., was inserted into the liquid iron to the bottom of the crucible to reduce the thermal convection of the liquid iron as much as possible. Aluminium was led into the liquid iron through the pipe and the effects of the reaction time and the initial oxygen content in the liquid iron on the formation of the inclusions was investigated. The results were summarized as follows:
(1) The layer-like alumina inclusions group was seen in most of the specimens with the naked eye. This group, however, was not detected in the specimen with the oxygen content of 0.03% and the reaction time of less than 400 sec.
(2) It was seen from the microscopic observation on the layer-like inclusions group that the thickness of this group increased with the reaction time but was independent of the oxygen content. With the increasing reaction time, the thickness had a tendency to attain a constant value at any oxygen content and with the increasing oxygen content, the inclusions were remarkable in growth and increased in numbers.
(3) It was predicted from the data obtained by the X.M.A. that the inclusions group did not exist at the Grube’s interface but existed at the aluminium content of less than 13%. This phenomenon was discussed by the use of the Fick’s second law and the nucleation theory in consideration of the time necessaly for the inclusions to form.
(4) The apparent diffusion coefficient of aluminium was estimated to study the effect of the formations of the inclusion. This coefficient reduced with the oxygen content and the reaction time.View full abstractDownload PDF (1342K) -
Yoshio Baba1966 Volume 30 Issue 7 Pages 679-683
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe influence of additions of 0.01 at% to 0.5 at%Ag or Cu to Al-2.5 at%Zn alloy on the pre-precipitation or clustering phenomena has been investigated mainly by means of resistivity measurements at the liquid nitrogen temperature.
The results are as follows:
(1) The number of spherical G.P. zones by Zn atoms or the density of the “clusters” increases by the addition of Ag. This influence is clearly observed for Ag more than 0.03 at% and could be attributed to the effect of clustering of Ag atoms immediately after quenching from the solution temperature or partial clustering formed during quenching.
(2) By the addition of Ag the rate of clustering is increased on aging above −20°C, but decreased at the temperature below −30°C. This effect is explained in terms of the activation energy for the migration of Ag atoms which is larger than that of Zn atoms and the participation of Ag atoms in the clustering of Zn atoms.
(3) The addition of Cu also increases a little the number of G.P. zones, but decreases the rate of culstering of Zn atoms at aging temperatures 20°∼−30°C. This effect is clearly observed for Cu more than 0.2 at%, but not for Cu less than 0.1 at%. This may be mainly due to a little larger binding energy between Cu atom and vaccancy than that between Zn atom and vacancy, although the clustering of Cu atoms themselves and the interaction between Cu clusters and Zn atoms must also be taken into consideration.View full abstractDownload PDF (1737K) -
Hajime Asano, Yoshichika Bando, Norihiko Nakanishi, Sukeji Kachi1966 Volume 30 Issue 7 Pages 684-688
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe specific heat and the lattice constant of Fe-Co alloys in the b.c.c. range have been measured. The specimens are prepared by the reduction of solid solution Fe1−xCoxC2O4·2H2O in hydrogen at 800°C. It has been confirmed that FeCo (CsCl type) superlattice exists over a wide range (30∼75 at%Co), and the so-called “550°C anomaly” of Fe0.5Co0.5 superlattice has been observed also in the alloys of 21∼60 at%Co. This anomaly appears at almost the same temperature in the composition range of 21∼50 at%Co (555°∼560°C), and its critical temperature falls rapidly when cobalt content is greater than 50 atomic per cent. There is a broad peak at about 555°C in specific heat curves of 21, 23, 25, 27 and 27.5 at%Co alloys. Formerly these peaks have been imagined due to the transition of Fe3Co superlattice. Judging from the concentration dependence of its critical temperature and the shape of the specific heat curves, it is reasonable to consider that these peaks do not correspond to Fe3Co superlattice but to the extension of the 550°C anomaly.
The effect of ordering on the lattice constant makes an increase in cell size in the 40∼60 at%Co alloys and a decrease in the 23∼40 at%Co alloys.
Neutron diffraction and Mössbauer measurement made on a slow cooled 25 at%Co alloy has shown no evidence for Fe3Co superlattice.View full abstractDownload PDF (2028K) -
Hisashi Suzuki, Kozi Hayashi, Ichiro Kawakatsu1966 Volume 30 Issue 7 Pages 689-693
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of the carbon content on the properties of WC-TiC-10%Co alloys containing a large amount of TiC, such as the width of (WC+β+γ) 3-phase range, lattice constants of β and γ-phase, magnetic saturation, transverse-rupture strength, etc., were investigated. WC-TiC-10%Co alloys containing up to 25%TiC (of cabides), and with various carbon contents in each 3-phase range, were vacuum-sintered at 1400°C for 1 hr (cooling rate, maximum 20°C/min).
The results were as follows: (1) It was found that the lattice constant of β-phase varies regularly in the 3-phase range with the change of the carbon content in the alloys. This behaviour may be accepted, because the carbon content of the β-phase changes widely towards carbon deficiency. (2) On the other hand, the lattice constant of the γ-phase also varies regularly with the carbon content in the phase range. This change is due to the variation of the dissolved W content in the binder, and seems to have no relation with Ti because Ti scarcely dissolves into the binder in this case. (3) Both β and γ-phase lattice constants vary only inside the 3-phase range in close connection with each other, but the value of the β or γ-phase reaches constant in both deficient carbon and excess carbon phase ranges neighbouring the 3-phase range. In the low and high carbon range, the constant values of the β-phase are 4.314±0.001 Å and 4.321±0.001 Å, respectively, and those of the γ-phase coincide with those of WC-10%Co alloys. (4) The width of the 3-phase range increases with TiC. For example, the value of 25% TiC alloy is about 0.8%C of carbides (the value of WC-10%Co alloy, 0.15∼0.18%Co). This is attributable to the change of the carbon content of the β-phase in equilibrium with the γ-phase. (5) The position of the stoichiometric carbon content of alloys with high TiC are found in free-carbon precipitation range. (6) The strength of the alloys decreases with increasing TiC content and a maximum strength is obtained in the high carbon 3-phase alloys. Other properties show the regular changes in the 3-phase range.View full abstractDownload PDF (1666K) -
Tadashi Ikeda, Shigeyasu Koda1966 Volume 30 Issue 7 Pages 694-700
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe surface self-diffusion coefficient of poly-crystalline silver has been measured as a function of temperature in the range from 200°C to 600°C by the radioactive tracer and lathe-sectioning technique. It has been found that the surface self-diffusion coefficient in the range from 200°C to 500°C can be expressed as follows: D_s = 4.5 ×10^-2 exp( -11,700/RT) cm2/sec.
The values of activation energy and frequency factor are in fairly good agreement with the result of Nickerson and Parker. It has been also found that Fisher’s model of the surface diffusion can be successfully applied in the present work. Considering the value of activation energy, it is suggested that diffusants are in a state of adsorption.View full abstractDownload PDF (1663K) -
Toshirô Kobayashi, Kôichi Takai, Hideyo Maniwa1966 Volume 30 Issue 7 Pages 700-706
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSAnalysis of the transition behaviour of mild steel in the Charpy impact test was made over a wide temperature range (100°∼−196°C) by observing the relationship between load and time during impact. As a result of this study, the transition behaviour in the Charpy impact test may be divided into six temperature regions. And it appears that usual transition temperatures such as Charpy-V 15 ft-lb energy. Charpy-V 0 percent shear and Charpy-V 15 mil lateral expansion are the yield point fracture criteria. On the other hand, Charpy-V 30∼35 ft-lb energy or Charpy-V 25 percent shear is the initiation (ductility) transition temperature at which no ductile crack can propagate after che maximum bending load is attained and rapid transition to brittle fracture occurs. It seems that this temperature correlates with NRL drop weight test NDT.
Another important transition temperature is the cleavage initiation temperature at which first cleavage fracture appears in the load/time curve and this temperature coincides with nearly 100 percent cleavage fracture appearance temperature in the brittle boundary specimens (i.e. carburized specimens). And it appears that this temperature is a measure of estimating the brittle crack propagation arresting temperature of a large scale test.
Furthermore we made attempt to obtain fracture toughness Gc values proposed by Irwin et al. from a small scale test such as the Charpy impact test in this case. For this purpose, we used brittle boundary specimens prepared by carburizing the free surface layers of Charpy specimens and measured load/time curves during fracture of these specimens. By these procedures we obtained some agreement with temperature gradient type ESSO test results. And estimates of Gc values relative to onset and arrest of brittle crack propagation were made and discussed.View full abstractDownload PDF (1961K) -
Tadayuki Nakayama, Hisao Fujikawa, Kenichi Kojima1966 Volume 30 Issue 7 Pages 707-708
Published: 1966
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDownload PDF (404K)
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