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Volume 38, Issue 7
Displaying 1-17 of 17 articles from this issue
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Masahiro Kagawa, Reiichi Ohno1974 Volume 38 Issue 7 Pages 581-586
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe deposition rate of titanium from titanium (IV) iodide was measured under the flow system in which the substrate was a high-purity titanium and the carrier gases were argon, hydrogen and their mixed gases. When the substrate was maintained at a constant temperature below 1450°C in argon, the deposition rate was controlled by the chemical reaction on the deposition surface and the rate decreased with an increase in the partial pressure of titanium (IV) iodide. Moreover, the lowest temperature of titanium deposition was higher than that of a closed system. These results suggest that, under the flow system, volatile compounds such as iodine formed in the deposition process of titanium and lower iodides formed by the etching reaction between titanium (IV) iodide and the titanium substrate are swept out of the gas phase near the substrate surface, and that the contribution of the etching reaction is great compared with the deposition under the closed system. A similar effect of the partial pressure of titanium (IV) iodide was observed in the deposition in the mixed carrier gases with relatively low partial pressure of hydrogen and also in the hydrogen carrier gas in the substrate temperature range of 1060 to 1200°C.View full abstractDownload PDF (462K) -
Yoshihiko Kunieda, Hachie Sawamoto, Takeo Oki1974 Volume 38 Issue 7 Pages 587-591
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSEffects of the various factors such as pH, temperature, dissolved oxygen, potential (or oxidation) and the reciprocal reaction with the solid particles of another metal sulfide, on the leaching of sulfide have been investigated for the purpose of clarifying the dissolution behavior of sulfides in dilute acid solution. Generally, many sulfides possess properties of a compound semiconductor. The conspicuous changes in the electric special character of semiconductor under illumination are known. Therefore, it is considered that the influence of illumination in the case of leaching should not be disregarded. However, there are few reports about this. In this investigation, the experiments on the effects of illumination were carried out in order to elucidate the dissolution mechanism of ZnS in acid solution and the galvanic reciprocal reaction of the direct selective leaching of ZnS from ZnS-CuS mixture concentrates.
The experimental results obtained are as follows:
(1) In the case of ZnS alone, the ZnS dissolution of H2S-evolution type was accelerated by illumination and its amount of dissolution increased.
(2) The galvanic reciprocal reaction of ZnS-CuS mixture concentrates was accelerated by illumination in the dilute acid solution at pH 1. ZnS was leached in accord with the dissolution reaction, ZnS=Zn2++S0+2e. This reaction was promoted with larger light energy.
(3) The ZnS dissolution of the H2S-evolution type from ZnS-CuS mixture concentrates was accelerated by illumination in the acid solution at lower pH such as −0.5.View full abstractDownload PDF (390K) -
Shigeoki Saji, Kazuyuki Asano, Shigenori Hori1974 Volume 38 Issue 7 Pages 591-599
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCu-0.2, 0.4, 0.8, 1.3, 1.9 and 3.9 wt%Ti alloys were aged at 450°C and then cold-rolled by 15, 30, 60 and 90% reductions in thickness, respectively. Hardening- and softening behaviors during isothermal annealing at 450°C of the cold-rolled specimens were studied by means of hardness measurement, X-ray diffraction technique, optical and transmission electron microscopy. The following conclutions were obtained:
(1) In the age-hardened and cold-rolled Cu-1.3, 1.9 and 3.9%Ti specimens hardening occurred in the early stages of the annealing process and then two steps of softening followed. The amount of anneal-hardening increased with increasing titanium content and increasing deformation. The maximum increment of hardness obtained during annealing after cold work was about 45 Hv; ∼12% of the hardness value of the same as-rolled specimen. This type of anneal-hardening was not obtained in Cu-0.2, 0.4 and 0.8%Ti specimens.
Formation of fine particles in the early stages of annealing after cold work in the vicinity of deformation bands may be an important factor of hardening, but the mechanism of this anneal-hardening is not unknown.
(2) The anneal-softening is due to the following three processes: (i) Growth and coalescence of Cu3Ti particles (equilibrium phase), (ii) recovery and recrystallization, and (iii) formation and growth of cellular precipitates. In the case of large amount of deformation, the processes (i) and (ii) are important, and the process (iii) is the main after a small amount of deformation. In the specimens with higher titanium content, the process (i) or (iii) is promoted and softening proceeds faster.View full abstractDownload PDF (1576K) -
Toshimi Sasaki, Toshihiro Yamada, Kazuyoshi Hatano1974 Volume 38 Issue 7 Pages 599-603
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA study has been made on the effect of residual stress on wear of the hardened steels as well as the change of the stress induced in the sliding surface under a metal-to-metal dry condition in air using a Pin-and-Disk type wear machine. In the present experimental condition, the wear rate was found to remain almost constant regardless of the extent of stress retained in the steels before the sliding test. The stress thus induced reached a maximum value of −110 kg/mm2. The rise surface temperature with increasing sliding speed gave rise to a decrease in the stress induced in the surface layer. This change was found to be determined only by the sliding condition, being almost independent of the retained stress in the steels before sliding. It was found that the wear rate decreases with increasing compressive stress in the sliding surface. Therefore, there seems to exist a certain correlation between the stress in the sliding surface and the wear rate in the steels.View full abstractDownload PDF (512K) -
Hisashi Suzuki, Kozi Hayashi1974 Volume 38 Issue 7 Pages 604-608
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of surface-grinding, i.e., γ→ε′ transformation and residual compressive stress (σr), on the mechanical properties of WC-(6∼30)%Co alloy were investigated in detail. The specimen almost free from the ε′ phase and the residual stress was prepared by sufficiently polishing the ground specimen so as to remove the surface-layer containing ε′ and σr (the thickness is about 30 μ).
The results obtained were as follows: (1) The hardness of the alloy and in particular that of the binder phase were increased by grinding. (2) The binder phase contracts by a small amount due to the γ→ε′ transformation, whereas the residual compressive stress was formed in the surface layer by grinding. (3) One set of crack length around Vickers indentation and frequency of crack path in the binder phase were larger in the orientation perpendicular to the grinding direction than in the orientation parallel to it. These were considered to be due to the anisotropy in the formation of a plate-shaped ε′ phase in relation to the grinding direction. (4) The contribution of σr to the transverse-rupture strength appeared to be neglected in common alloys, but it became considerably large in high-strength alloys. The amount of the contribution was considered to depend on the perfection of specimens, the surface state and distribution of σr, etc.View full abstractDownload PDF (408K) -
Shigeo Zaima, Hirohisa Takeda, Sadamu Morishita1974 Volume 38 Issue 7 Pages 609-614
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the aluminium-silicon system, eutectic alloys (about 13%Si) and hyper eutectic alloys (17∼23%Si) in particular show good high-temperature strength, comparatively small coefficients of thermal expansion and good anticorrosive properties. These alloys are therefore, rare of increasing concern for piston and other uses. In machining these alloys, however, it is difficult to obtain good cut surfaces and, especially, the hyper-eutectic alloys show severe tool wear. In this study, the hot machining is applied to these high silicon aluminium alloys for the improvement of their machinability. The turning tests are conducted on these alloys by varying the heating temperatures between 100 and 300°C at the beginning of cutting tests by gas heating. In addition, the orthogonal cutting tests of plate-type specimens are performed to compare the obtained results.
The shear stress on the shear plane decreases and the cutting resistance decreases with increasing heating temperature. As the heating temperature and the silicon content increase, the rate of increase of shear angle becomes higher and, in addition, the formation of a built-up edge decreases with improvement of the cut surface. When the temperature of the tool edge is over 500°C, however, the tool wear progresses severely in hype-eutectic alloys.View full abstractDownload PDF (669K) -
Shigeo Zaima, Yasuo Suzuki, Masao Yamashita1974 Volume 38 Issue 7 Pages 615-620
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this paper, using epoxy resin plates for an orthogonal cutting model similar to orthogonal aluminium cutting, the stress distribution in the specimen in the vicinity of tool tip is pursued by changing the factors corresponding to the cutting conditions. As a whole, in this experiment, σx, i.e. the stress in the x-direction corresponding to the cutting direction, is compression in the front of the tool tip and is tension in the rear of the tool tip; σy, i.e. the stress in the direction perpendicular to the x-direction, is compression in the whole area. When the rake angle of the tool is small, σx shows a large compressive force and σy distributed as compression on the chip side increases. In the case of a round nose tool tip, both σx and σy increase to the compression side just in front of the tool tip. When the radial force increases in comparison with the principal force, the compression σx in the front of the tool tip increases and the tension σx in the rear of the tool tip decreases.View full abstractDownload PDF (525K) -
Shigeo Zaima, Akiyasu Yuki, Fujio Yano1974 Volume 38 Issue 7 Pages 620-626
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe growth and falling off of the built-up edge occur frequently in the drilling opereration of aluminium alloys and the behavior of the built-up edge strongly affects the conditions of the drilled surfaces. In this study, the behavior of the built-up edge in the drill edge, quality of the drilled surfaces, etc. in the drilling of aluminium alloy 5052-F are investigated by quickly stopping the cutting operation of the twist drill, in order to examine the aluminium drilling mechanism. The results obtained are as follows. In dry drilling, the built-up edge grows remarkably, the adhering condition of the built-up edge changes continuously and the actual rake angle which participates in cutting shows a nearly constant value of about 35° on the drill edge, regardless of the change in the drill rake angle between −30° and +30° from the center to the magin, and the nose radius of the built-up edge is nearly constant at about 60 μ. When the cutting fluid is dropped in drilling, the built-up edge decreases suddenly, but, in drilling using dry ice cooling and no cutting fluid, the built-up edge shows dominant growth. This results suggests that lubrication is more effective for the control of the built-up edge than cooling. It is also shown that the drilled surface (the conical surface, particularly the cylindrical surface) is greatly affected by the built-up edge.View full abstractDownload PDF (700K) -
Shigeru Asano, Kazuhisa Hara, Yoichi Nakai, Namio Ohtani1974 Volume 38 Issue 7 Pages 626-632
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDiffusion coefficients of hydrogen in a mild steel were measured by the method of electrochemical permeation at room temperature and above. In order to evaluate the trapping effect of dislocations, the influence of cold work and quenching treatments on hydrogen diffusion was examined in detail, together with the observation of recovery processes in annealing. The results obtained are summarized as follows: (1) The diffusivity of hydrogen was significantly decreased by cold work. Its variation ranged over three orders of magnitude at 20°C. (2) It was shown from recovery that the trapping effect due to cold work was attributed to dislocations, but not to void-type defects as often suggested. (3) The dislocations produced by martensitic transformation gave rise to just the same trapping effect as the dislocations produced by cold work. (4) It was shown from temperature dependence of hydrogen diffusion that the binding energy of hydrogen with dislocations was 6300 cal/mol, which agreed well with the estimate from internal friction. (5) The method of estimation of dislocation density from the apparent diffusivity of hydrogen was established, which was confirmed to provide reasonable values of dislocation density.View full abstractDownload PDF (661K) -
Tohru Arai, Takuo Ito, Noboru Komatsu1974 Volume 38 Issue 7 Pages 632-637
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA simple measuring apparatus was contrived to determine isothermal and continuous cooling transformations of steels with simple procedures by the method of differential thermal analysis. Specimens and references 1 mm in diameter were prepared, respectively, and a thermocouple was welded to each of them. This apparatus comprises an austenitizing and cooling furnace and an isothermal salt bath.
The TTT diagram and the Ms temperature of SUJ 2 bearing steel were determined by this method, and the results were in good agreement with those obtained by the metallographic or Greninger-Troiano method. The CCT diagram of S 45 C structural carbon steel was also, found to have satisfactory accuracy for practical purposes. In this method, it was permissable for the specimens to be subjected to plastic deformation during the measurement, so that the CCT diagram for the steel being thermomechanically treated could be obtained. The method can also be used for obtaining the CCT diagram for cast iron cooled from the molten state. The DTA method for measuring transformations seems to be of great practical value in obtaining transformation diagrams which are required not only for heat treatment but also for thermomechanical treatment, welding and casting.View full abstractDownload PDF (667K) -
Minoru Yamamoto, Taketo Sakuma, Taiji Nishizawa1974 Volume 38 Issue 7 Pages 637-645
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSColumnar grains of β-phase were produced on single- and polycrystals of copper by the solid phase diffusion of zinc atoms, and their crystallographic features were studied by means of X-ray measurements. Special attention was paid to determine the growth direction of β-phase and to study the structure of the α⁄β interface. The coarse grains of β-phase were found to grow on the α-phase, in agreement with Kurdjumov-Sachs’ or Nishiyama’s orientation relationship. The growth direction of these grains and the associated interface structure were found to be affected by the surface orientation of the single crystals. The α⁄β interface was as follows:
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In all cases, β-phase grains had a tendency to grow so as to attain a well-fitted α⁄β interface, depending on the orientation of the original single crystals. Much finer β-phase grains were produced on polycrystalline copper. These β-phase crystals had a ⟨111⟩ preferred orientation parallel to the growth direction. The results indicate that the growth of β-phase occurs by the following mechanism: (a) epitaxial growth on single crystals of copper and (b) preferential growth on fine grained polycrystals of copper.View full abstractDownload PDF (1046K) -
Hideya Okada, Yuzo Hosoi, Seizaburo Abe, Shuichi Yamamoto1974 Volume 38 Issue 7 Pages 646-653
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA new method was studied to evaluate the stress corrosion susceptibility of austenitic stainless steels from stress-strain curves observed under controlled tensile strain rate in MgCl2 solution boiling at 143°C. The results indicated that when the strain rate was low enough to cause metal dissolution at slip steps, stress corrosion cracking occurred. The fracture strain decreased with the decrease of strain rate. A good relation was obtained between the fracture time in the constant load test and stress corrosion susceptibility parameter, Pc(εc+1)⁄P(ε+1), where ε is the strain at the maximum load P under the strain rate of 0.67×10−2 sec−1, and εc is the strain at the maximum load Pc under the strain rate of 1.67×10−5 sec−1 in MgCl2 solution boiling at 143°C.View full abstractDownload PDF (1507K) -
Kunio Takada, Kichinosuke Hirokawa1974 Volume 38 Issue 7 Pages 654-658
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSRecently, various samples containing rare earth elements have actively been studied from standpoints of metallurgy, solid state physics and non-stoichiometric chemistry. As the vehicle for these investigations, effective analytical methods of those elements are required. Determination of rare earth elements in various samples by the X-ray fluorescence method and those of impurity levels in high pure rare earths by the d.c. arc emission spectrographic method have been studied. In the X-ray fluorescence method, rare earth elements were precipitated as fluoride. Compared with the rare earth oxide, the rare earth fluoride precipitate absorbed little moisture and carbon dioxide in atmosphere. Furthermore, its preparation procedure was easier rather than the glass bead technique. Detection limits of rare earth elements were extended by this fluoride procedure because of no dilution with the fusing agent. Detection limits for Y (YKα) and Yb (YbLα1) were about 5 μg, for Ce(CeLβ1) and Gd(GdLα1) about 20 μg, and those elements of about 50 μg were analyzed with the coefficient of variation less than 2%, respectively. Many reports have been published for the chemical analysis of high-purity rare earths by the d.c. arc emission method. Most of those reports were concerned with the determination of impurity rare earths in pure rare earths (e.g. Y, La, Eu, Yb, etc.) which gave simple spectra with rather less lines and low background. The satisfactory results were obtained by d.c. arc emission for 10 ppm Eu in Yb and for 10 ppm Y in La. On the other hand, few have been reported on the determination of high pure rare earths (e.g. Ce, Pr, Nd, Sm, etc.) with multi-component emssion spectral lines of strong intensity and high background. Therefore, the determination of 10∼500 ppm Y2O3 in Sm2O3 was investigated by the d.c. arc emission spectrographic method. Yttrium was separated from samarium as double salt with saturated sodium sulfate solution. The determination of trace yttrium in high-purity Sm2O3 became possible by the separation procedure. The best yttrium spectrum line for determination in the range of 3100∼4700 Å was YII 3633.123 Å and other lines could not be employed because of weak line intensity and high interference by samarium spectra. By the method proposed, trace amounts of Y2O3 in Sm2O3 were determined, and the coefficient of variation of sample containing 108 ppm Y2O3 in Sm2O3 was about 10%.View full abstractDownload PDF (430K) -
Kenji Morinaga, Yukio Suginohara, Tsutomu Yanagase1974 Volume 38 Issue 7 Pages 658-662
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSMeasurements of electrical conductivity (K) of CaO-SiO2-TiO2 melts have been carried out in order to find out the effects of TiO2 in the CaO-SiO2 system. The results show that the electrical conductivity depends mainly upon the SiO2 content, that is, the contribution of TiO2 to the electrical conductivity is almost equal to that of CaO in the melts. The Ti ions in the silicate melts are considered to be located in the center of both octahedral and tetrahedral structures for oxygen. Provided that the ratio of Ti(oct.)/Ti(tetr.) can be determined by the CaO/SiO2 ratio and Ti(oct.)/Ti(tetr.) is equal to unity when the CaO/SiO2 ratio is unity, the distribution of Ti(oct.) and Ti(tetr.) present in the melts can be estimated for the entire composition range. The calculated parameter for electrical conductivity was introduced and the effects of TiO2 was discussed.View full abstractDownload PDF (398K) -
Tokio Kato, Takeo Oki1974 Volume 38 Issue 7 Pages 663-668
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTo clarify the anodic dissolution mechanisms of nickel sulfide and pyrrhotite in acid solution, measurements of the electrode potentials and anodic polarization behavior, and galvanostatic anodizing were carried out.
(1) Nickel sulfide dissolved anodically in sulfuric and perchloric acid solutions through the following two simultaneous reactions;
(i) NiS→Ni2++S0+2e,
(ii) NiS+4H2O→Ni2++SO42−+8H++8e.
(2) Pyrrhotite dissolved anodically with high current efficiency in perchloric acid solution through the following principal reaction: FeS→Fe2++S0+2e.
In sulfuric acid solution, however, an anodic film which consisted mainly of anodized elemental sulfur and iron compounds was formed. As a result, the anodic potential of pyrrhotite in galvanostatic anodizing was extremely unstable and the dissolution current efficiency was considerably lower than that in perchloric acid solution.View full abstractDownload PDF (676K) -
Yutaka Hiraoka, Kozo Osamura, Yotaro Murakami1974 Volume 38 Issue 7 Pages 669-672
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIt is well known that during a pre-precipitation process in which the formation of Guinier-Preston zones takes place, an increase of resistivity at its early stage, followed by a decrease, occurs in a number of age-hardenable aluminium-base alloys. Recently we have experimentally determined the contribution of the G.P. zones to the electrical resistivity and it has been shown that the scattering power due to a G.P. zone increases with its size.
The object of the present paper is to investigate in detail the influence of size and shape of G.P. zones on the scattering power. The electrical resistivity, the Hall coefficient and X-ray small-angle scattering measurements have been performed for several Al-Zn alloys aged for 1000 min at 20, 60 and 110°C. The value of the electrical resistivity and the Hall coefficient were analyzed in order to obtain the relaxation times due to a G.P. zone scattering by using the two-band model with the aid of the size distribution of the zones.
It is shown that the scattering power of a G.P. zone increases with its size, but this rate changes at the zone size of about 10 Å. The change seems to result from the shape change of the G.P. zone.View full abstractDownload PDF (325K) -
Keisuke Ishikawa, Kazuo Tsuya1974 Volume 38 Issue 7 Pages 673-674
Published: 1974
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSDownload PDF (82K)
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