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Volume 37, Issue 8
Displaying 1-21 of 21 articles from this issue
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Yoshihiko Kunieda, Hachie Sawamoto, Takeo Oki1973 Volume 37 Issue 8 Pages 803-808
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe dissolution mechanism of metal sulfides in the acidic solution has not been sufficiently theorized because of their complex dissolution. The present investigation on the contribution of dissolved oxygen to the dissolution reactions was carried out, in order to elucidate the dissolution mechanism of ZnS and the selective-direct leaching of ZnS from ZnS-CuS mixture concentrates.
The experimental results obtained were as follows:
(1) In the dissolution of ZnS alone, the reaction of the H2S-evolution type occurred mainly in the experimental range of pH. In the dissolution of the ZnS-CuS mixture, the selective dissolution reaction of ZnS (S°-formation type in this case) occurred in addition to H2S-evolution reaction owing to the galvanic reciprocal reaction. This reaction is as follows:
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(2) In the dissolution of ZnS alone, the effect of dissolved oxygen on the dissolution of ZnS was very little in the acidic solution of pH 1.0. In the acidic solution of pH-0.5, the amount of dissolved Zn2+ decreased as the amount of dissolved oxygen increased.
(3) In the dissolution of the ZnS-CuS mixture, the amount of dissolved Zn2+ and the amount of formation of S° in the acidic solution of pH 1.0 increased with increase in CuS addition and/or oxygen supply as compared with the dissolution of ZnS alone.
(4) In the dissolution of the ZnS-CuS mixture in the acidic solution of pH-0.5, the amount of formation of S° increased with increase in CuS addition or oxygen supply, but the amount of dissolved Zn2+ decreased as compared with the dissolution of ZnS alone. When a sufficient amount of oxygen was supplied, the amount of formation of S° increased and the amount of dissolved Zn2+ remarkably decreased.View full abstractDownload PDF (483K) -
Kaizo Kuwahara, Hisashi Kawabe1973 Volume 37 Issue 8 Pages 809-814
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe internal friction of metal films was investigated by means of the torsion pendulum method. The films were produced by the evaporation on glass substrates which were covered with thin film of sodium chloride. They were removed from the substrates by immersing into water.
It was found that the free decay oscillation curve of bismuth films has a very high damping coefficient and also has such a form that an exponential decay curve is superposed on an ordinary cyclic decay curve symmetrical about the base axis of time. The initial value of the exponential decay part deviates to the initially twisted direction and the deviation is found to increase and then saturate with increasing holding time of the films in the initially twisted state. Other metal films which include Ag, Al, Au, Cu, 55 Cu-Ni and Sn films have no such a remarkable asymmetry as observed on bismuth films. It is shown that the behavior of bismuth films which is given initial displacement is satisfactorily explained by a model composed of the standard linear solid and a mass hanged under that.
The value of Q−1 of bismuth films was determined as a function of temperature for two frequencies. The activation energy obtained from the peak shift is 6×103 cal/mol. This value is close to the value of 5.5×103 cal/mol which is obtained from the temperature dependence of the critical holding time.View full abstractDownload PDF (523K) -
Toshio Shikata, Tokio Yokoyama, Satoshi Shikanai1973 Volume 37 Issue 8 Pages 815-819
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSA good heat resistant and non-porous siliconized layer containing 6∼11% Si was obtained on the surface of cast iron with the thickness of 30∼80 μ. The microscopic structure of the siliconized layer was studied by electron microscope and X-ray diffraction method, in comparison with Fe-9% Si alloy. The results are as follows:
(1) Etched patterns were observed in the siliconized layer. The pattern showed the oriented structure like Widmanstätten structure, and vanished through reheating and rapid cooling. The same kind of pattern was observed in Fe-9% Si alloy by cooling slowly from above 900°C or holding below 600°C.
(2) The structure observed both in the siliconized layer and Fe-9% Si alloy was explained in connection with the formation of Fe3Si superlattice. It is thought that anti-phase domain boundaries of the Fe3Si superlattice of the DO3 type was developed by etching.View full abstractDownload PDF (943K) -
Yûkichi Kosaka1973 Volume 37 Issue 8 Pages 820-828
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn a previous paper it is shown that a solidification process which has been termed the “K-type non-eutectic reaction” proceeds prior to the eutectic reaction in Fe-C-Si alloys undercooled severely.
In this investigation, the freezing behavior in the same alloys undercooled at various temperatures below the theoretical freezing point has been studied by using an isothermal solidification technique, and solidification processes termed the “G-type non-eutectic reaction” and the “C-type non-eutectic reaction” have been demonstrated.
The similarity between the G-type non-eutectic reaction and the C-type non-eutectic reaction does exist in the solidification pattern of “crystallization of austenite in the melt and precipitation of graphite in the supersaturated austemte”. In the G-type non-eutectic solidification process, however, excess carbon in the supersaturated austenite is precipitated on the eutectic graphite phase formed by the graphite-eutectic reaction, whereas in the C-type non-eutectic reaction it is precipitated along the austenite-cementite interface formed by the cementite-eutectic reaction.
From the experimental data obtained in this investigation, an isothermal solidification diagram for the alloy tested has been constructed. The solidification diagram consists of three sets of freezing curves; the first is for the austenite-graphite eutectic reaction, the second is for the austenite-cementite eutectic reaction and the third is for the K-type non-eutectic reaction.View full abstractDownload PDF (1455K) -
Ichiro Kawakatsu, Tadashi Osawa1973 Volume 37 Issue 8 Pages 828-833
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe wettability of a silver brazing alloy (BAg-8; Ag-28 wt% Cu alloy) on carbon steel plates with different carbon contents were investigated in relation to the effect of brazing atmosphere. The wettability was examined by measuring the spreaded area of the silver brazing alloy on the base metal. Pure hydrogen and mixed gases of hydrogen and nitrogen in various composition were used for brazing atmosphere. The results obtained are summarized as follows:
(1) The spreading area of the silver brazing alloy on carbon steel tends to increase parabolically with heating time. The apparent activation energy for spreading of molten BAg-8 on the carbon steel was about 41.1 kcal/mol.
(2) The spreading area was affected by the content of hydrogen in brazing atmosphere, that is, the higher the content of hydrogen the better becomes the spreadability. The spreading area on the base metal of low carbon steel (0.1% C) in N2-20 vol% H2 atmosphere was approximately 50% of that in pure hydrogen.
(3) The spreading area varied with the carbon content in the base metal and decreased with increasing carbon content.
(4) The interfacial tension between molten BAg-8 and the mixed gases of hydrogen and nitrogen tends to decrease with increasing content of hydrogen. This shows that the better spreadability in the brazing atmosphere with higher content of hydrogen would be due to the effect of hydrogen which reduces not only base metal oxides but also interfacial tension.View full abstractDownload PDF (592K) -
Sakae Takeuchi, Osamu Uemura, Susumu Ikeda1973 Volume 37 Issue 8 Pages 834-840
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe heats of mixing of liquid copper alloys were measured from temperature changes of liquid alloys on mixing.
In the liquid Cu-Bi alloy, a heat absorption which depends parabolically upon composition was observed. On the other hand, heat of mixing curves with a deep valley of heat evolution in the range of 80% to 75% Cu were obtained for the liquid Cu-Sb, Cu-Ge, Cu-Sn and Cu-In alloys.
It is supposed that Cu and Bi atoms are randomly mixed in the Cu-Bi alloy, but in the other alloys such as Cu-Sn and Cu-In, all the constituent atoms cannot always be randomly distributed.
It may be expected from the above results and other physical properties that in these liquid alloys some atoms are randomly distributed, but others form clusters of small groups of atoms. These clusters appears to be molecules of the type AmB bound by a sort of covalent bond and have a flexible structure different from a rigid molecule. They have been named as pseudo-molecules. The heat evolved on mixing may be mainly due to the formation of the pseudo-molecules.
Under the above assumption, the partition function of an assembly consisting of the pseudo-molecules and free atoms and then the free energy of such an assembly were calculated. From the condition of the minimum free energy, the distribution of the pseudo-molecules nR was also determined as a function of alloy composition. In the case of the liquid Cu-Sn and Cu-In alloys the values for the heat of mixing calculated from the above nR function are in good agreement with the observed values. Considering the large difference between atomic volumes of Cu and Bi, the heat of mixing of the liquid Cu-Bi alloy was estimated. The calculated results give a parabolic curve with a maximum at 40% Bi, which is in good agreement with the experiment.View full abstractDownload PDF (531K) -
Takamichi Iida, Akio Kasama, Zen-ichiro Morita, Ikuo Okamoto, Seiji To ...1973 Volume 37 Issue 8 Pages 841-848
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSViscosities of mercury-based dilute binary alloys containing 1∼3 at% Ag, Au, Zn, Cd, Ga, In, Tl, Sn, Pb and Bi have carefully been measured by an improved capillary method over the temperature range between their melting points and 230°C. In liquid pure mercury, the relation between logη and 1⁄T did not lie on a straight line over the entire temperature range measured, but the slope of the straight-line changed by about 8% at the temperatures in the vicinity of 70 and 150°C and decreased with increasing temperature. The viscosity of mercury increased at a rate of about 1∼5% with the addition of 1 at% solute, and the increasing tendency was considerably larger for Ag, Au and Pb but smaller for In, Cd and Sn. Bi showed a different behavior in the change of viscosity from the others. From the results of the present experiment, it becomes manifest that an equation for the viscosity of dilute binary alloys can be approximately expressed in terms of the square root of the product of the atomic weight by the melting point of solute as a parameter.View full abstractDownload PDF (610K) -
Koji Yuasa1973 Volume 37 Issue 8 Pages 849-854
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe main advantages of warm forging have been thought to be in that products are worked more precisely by warm forging than by hot forging, under a lower deformation pressure than by cold forging. However, little attention has been given to the mechanical properties of warm-forged products. It is necessary to have a fuller understanding of the effects of the working conditions on the mechanical properties of warm-forged products for applications of warm forging, because warm-forged products have various mechanical properties according to the working conditions. Therefore plain carbon steels containing 0.20% C to 0.53% C have been extruded in the temperature range from 300°C to 900°C with reductions of 40, 60 and 80% in cross-sectional in order to investigate the effects of working temperature, reduction of area and carbon content on the mechanical properties and microstructures of the products.
The results obtained were as follows:
(1) Tensile strength, elongation and hardness of products varied rather regularly with carbon content and working temperature. But they were not greatly influenced by the reduction of area.
(2) The impact values varied in a complex manner with the combination of carbon content, working temperature and reduction of area. The impact values of products extruded with high sectional reductions in area increased remarkably even at lower working temperatures.
(3) The increase in impact values of warm-extruded low carbon steels seems to be due to the recovery and recrystallization of ferrite, while medium carbon steels seems to increase their impact values due to the fibrous pearlite formed by extrusion in addition to the recovery and recrystallization of ferrite.View full abstractDownload PDF (972K) -
Mikio Morita, Kiyoshi Fukui1973 Volume 37 Issue 8 Pages 855-860
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe textures of cold rolled Ni and Ni-Fe alloy foils are determined by the X-ray transmission pole figure method.
Ni-Fe alloys from pure Ni to 28 Ni-Fe, which have a face centered cubic lattice at room temperature, show the Cu-type rolling texture, {110}⟨112⟩+{112}⟨111⟩. In pure Ni and 50 Ni-Fe, the {112}⟨111⟩ component is stronger than the {110}⟨112⟩ component. Stacking-fault probability in pure Ni and 50 Ni-Fe alloy may be smaller than that of 70 and 79 Ni-Fe alloys.
Most ternary alloys of 78 Ni-Fe- (Cu, Cr, Mo, V, Nb & Ti) also show the Cu-type rolling texture except Nb. The rolling texture of Nb-Ni-Fe alloy foils is close to the α-brass type texture, {110}⟨112⟩.
Mo-permalloy (4.5 Mo-79.6 Ni-Fe) behaves in a different manner: It has the Cu-type rolling texture in thicker foils of the order of 0.1 mm, but its texture changes to a texture closer to the α-brass type when heavily rolled to a several micron thickness.View full abstractDownload PDF (420K) -
Mikio Morita, Kiyoshi Fukui1973 Volume 37 Issue 8 Pages 861-866
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe textures of recrystallized Ni and Ni-Fe alloy foils are determined by the X-ray transmission pole figure method.
Most of binnary and ternary Ni-Fe alloy foils have the sharp cube recrystallization texture. But, in very thin foils of several micron thickness, the cube texture does not develop as sharply as in thicker foils and rotates 10∼20° around the ⟨001⟩ axis of the rolling direction.
Though Ni-Fe alloy foils rolled at liquid nitrogen temperature have the α-brass type rolling texture, they also show the cube recrystallization texture.
It is shown that Mn is effective in developing the cube texture in Ni-Fe alloys.
The mechanism of developing the recrystallization texture is also discussed.View full abstractDownload PDF (445K) -
Mikio Morita, Kiyoshi Fukui1973 Volume 37 Issue 8 Pages 866-871
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSNi-Fe alloys with the cube texture were cold-rolled to several microns thickness and their texture development was examined by the X-ray transmission pole figure method.
Since the cube texture was a quasi-stable orientation, it remained until a fairly advanced stage of cold-rolling. When cold-rolled heavily, the cube orientation rotates to near {641}⟨\bar112⟩.
The heavily cold-rolled foils in which the initial texture rotates to an orientation near {641}⟨\bar112⟩ develops a sharp cube texture after annealing, but the foils which retain the initial texture do not. The (100)[001] orientation in deformed matrices, which exist near the surface, may become nuclei of recrystallization grain.View full abstractDownload PDF (413K) -
Hakaru Masumoto, Kiyoshi Watanabe, Shigehiro Ohnuma1973 Volume 37 Issue 8 Pages 872-875
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCrystal structures and magnetic properties of Pd-Mn-Te alloys have been investigated by means of X-ray diffraction and magnetic balance, respectively. It has been found that the Pd-Mn-Te alloys of stoichiometric composition is a Clb type and forms a solid solution having lattice parameters of about 6.269∼6.274 Å at room temperature in the composition range of Pd1.0125Mn0.975-Te1.0125∼Pd0.975Mn1.05Te0.975 alloys. Moreover the compound PdMnTe was supposed to be antiferromagnetic from the temperature dependence of magnetic susceptibility and reciprocal magnetic susceptibility, the Néel temperature being 22°K. The paramagnetic Curie temperature and paramagnetic effective Bohr magneton number per Mn atom were evaluated to be 25°±3°K and 5.28 μB, respectively.View full abstractDownload PDF (325K) -
Akihisa Inoue, Tsugio Ogura, Tsuyoshi Masumoto1973 Volume 37 Issue 8 Pages 875-882
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to clarify the deformation behaviour of cementite in steels, observations by a transmission electron microscope were made on the dislocation structures of cementite in cold-rolled carbon steels.
The results obtained are summarized as follows:
(1) A plastic deformation of cementite due to dislocation gliding was demonstrated to occur in the carbon steels. The gliding was also found to take place very heterogeneously; it was concentrated only on several slip planes being in parallel and 0.2∼0.3 μ apart from each other.
(2) Many straight dislocations were observed on slip planes, and the density of such dislocations was greatly increased in proportion to the increase in the deformation of steels. In addition to the dislocation, moiré pattern, cell wall, and stacking fault were also observed in the deformed cementite.
(3) Slip planes of cementite crystals at room temperature were determined to be (100)θ, (010)θ and (001)θ. The possibility of two slip directions, [001]θ on (010)θ and [010]θ on (001)θ, was suggested from a detailed observation of the image of pile-up dislocations on the slip planes. A slip direction, [010]θ on (100)θ, was also presumed to be a probable one. However, it must be noted that the slip direction [001]θ on (010)θ is not consistent with the one expected from the crystalline structure of cementite. It was confirmed from these experimental results that the major part of dislocations on their slip planes had a screw nature.
(4) The fracture of lamellar cementite proceeded by the following way; the gliding of cementite crystals in the heterogeneous manner results in division of the original cementite crystal into several undeformed blocks. The mutual gliding displacement between two adjacent blocks (height of slip steps) increases with a successive deformation of the cementite. Finally, the cementite is perfectly broken away along the boundaries of the blocks probably due to the stress concentration at the slip steps.View full abstractDownload PDF (1612K) -
Takefumi Horiuchi, Yoshiyuki Monju, Nobuyuki Nagai1973 Volume 37 Issue 8 Pages 882-887
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe possibility of enhancing the superconducting properties in Ti-24∼65 at% Nb-5∼35 at% Zr-4∼10 at% Ta quaternary alloys was investigated.
Specimens were prepared by arc-melting, hot forging, cold swaging and cold drawing. Superconducting transition temperature (Tc), resistive critical field (Hcn), residual resistivity (ρn) and Vicker’s hardness number (Hv) of the specimens were measured.
It becomes clear that:
(1) The quaternary alloy showed a maximum Hcn of 131 kG at a composition Ti-25 at% Nb-10 at% Ta-5 at% Zr.
(2) Hcn of the Ti-32.3 at% Nb-32.3 at% Zr ternary alloy was increased from 98 kG to 109 kG by the addition of 6 at% Ta and then slightly decreased by the addition of surplus Ta.
(3) Ti and Nb atoms showed equivalent influence on Hcn and Hv of the quaternary alloy. The addition of Zr on Ti-Nb-5 at% Ta and Ti-Nb-10 at% Ta alloys decreased Hcn and increased Hv.
(4) Tc was higher in the Nb corner and decreased monotonously as approaching the Ti and Zr side. In contrast to the behavior of Tc, ρn decreased in the Nb corner and increased in the Ti and Zr side.View full abstractDownload PDF (418K) -
Shozo Yoshioka, Mitsuo Mera, Kenji Morii1973 Volume 37 Issue 8 Pages 888-894
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of the interaction between grains on the deformation behaviours of copper bicrystals have been studied. Four kinds of bicrystals were rolled with the trace of grain boundary as a rolling direction at room temperature reversing end to end between passes. Each partner of these bicrystals had initially the same orientation as that of any one of the several components of the pure metal type rolling texture in fcc metals, i.e. (1) N 101, (101)[\bar121]+(\bar10\bar1)[\bar121], (2) S 101, (101)[\bar121]+(211)[\bar111], (3) N 513, (513)[\bar121]+(\bar5\bar1\bar3)[\bar121], (4) S 513, (513)[\bar121]+(100)[011].
The shear deformation in the rolling plane was almost restrained in the type N bicrystal, but a severe shear took place on both partner grains in the type S bicrystal. These shape changes were explained qualitatively from the viewpoint of the interaction between component grains during rolling deformation.
The initial orientations of the (101)[\bar121] and (513)[\bar121] grains were maintained up to high reductions independently of the type N or S. The (211)[\bar111] grain was deformed with shear in the rolling plane accompanying a small fluctuation of the orientation about the rolling direction. In the (100)[011] grain, the lattice rotation toward (211)[\bar111] occurred.
The orientation changes in thes grains seem not to contradic to those deduced from the slip systems observed by replica electron microscopy, except for that in the (513)[\bar121] grain.View full abstractDownload PDF (1176K) -
Thermal Stability of Cu-0.5% Ag-Al2O3 Alloy and its Application to an Electrode Tip for Spot WeldingSen-ichi Yamada, Noboru Komatsu1973 Volume 37 Issue 8 Pages 895-900
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to study the thermal effect on an internally oxidized and extruded Cu-0.5% Ag-Al2O3 alloy, investigations were made on the relation between heat treat ment and mechanical properties with metallographic observation. As a practical application, the alloy was used as an electrode tip for spot welding.
The following results were obtained:
(1) As-extruded rod remarkably decreased in strength when annealed at 1060°C for 10 hr, although the decrease was very slight in the case of annealing at 1050°C for 1 hr.
(2) The alloy which was cold worked by an area reduction of 75% after extrusion had a tensile strength of about 57 kg/mm2, but its strength was decreased after annealing at temperatures over 400°C. The cold-worked alloy, however, kept higher mechanical strength than the as-extruded alloy after heat treatment at any given annealing temperature. When the extruded alloy was hot worked at 800°C by an area reduction of 75%, no increase of strength was observed, while both elongation and reduction area increased.
(3) The alloy, annealed at 1060°C for 10 hr, increased in strength through 75% cold working, but it decreased when it was further annealed at temperatures over 400°C. But even after annealing at 800°C for 1 hr, the alloy kept the same mechanical properties as the extruded alloy.
(4) When this alloy was used as an electrode tip for spot welding, the life was 7∼15 times longer than a Cu-Cr tip.View full abstractDownload PDF (1007K) -
Tsutomu Yamamura, Tatsuhiko Ejima1973 Volume 37 Issue 8 Pages 901-907
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn order to clarify the relative importance of various factors for the solute diffusion, the diffusion coefficients of Cu, Ag and Au in liquid copper and silver have been measured by using the capillary reservoir method in the temperature range 1100 to 1300°C. The results obtained in the current investigation are summarized as follows:
(1) In liquid copper, the diffusivity increases as the radius and the mass of diffusing particle decrease. On the other hand, the difference between the diffusivities of the solutes and the solvent in liquid silver is not so significant as in the case of liquid copper. This may be caused by the small degree of the viscosity and the large free volume of liquid silver.
(2) The activation energies of solutes having the solute-solvent binding energy higher (or lower) than the solvent-solvent binding energy are lower (or higher) than that of solvent self diffusion.
(3) Applicability of the critical free volume and the microfluctuation theories have been examined on the basis of the results obtained. It is shown that the diffusion theories are improved by taking account of the mass effect, the size effect and the solute-solvent binding energy, respectively.View full abstractDownload PDF (641K) -
Minoru Tanaka, Yoshihiko Fukui, Sakae Takeuchi1973 Volume 37 Issue 8 Pages 907-916
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCharacteristics of the thermal motions of ions in a model of liquid Na near the melting point are investigated using the simulation of the molecular dynamics first developed by A. Rahman.
The first half of the note is devoted to report a manual of the simulation of the LRO-II pair-potential system. Examination on the equilibrium conditions of the small system (N=864) and the ergodicity of the average over the file of motion of the system proves that the accuracy of the file made by the use of a home-manufactured computer (NEAC 2200, model 700) is comparable to that obtained by IBM, CDC 6600, etc.
In the last half, characteristics of the thermal motions of Na ions are investigated. It has been made clear that the thermal diffusion of an individual ion is not the jumping diffusion type but a smooth oscillatory migration type. This motion is considered to be cooperative with 10∼15 surrounding ions, i.e. the first shell neighbours in the sense of g(r). These local collective motions correspond to the characteristic peaks in the dynamic structure factor S(Q,ω) of the neutron inelastic scattering around 1013 rad/sec in the value of ω.View full abstractDownload PDF (890K) -
Kenzo Kon, Namio Ohtani1973 Volume 37 Issue 8 Pages 917-922
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe stress corrosion cracking of single and bicrystals of Al-4% Cu alloys, prepared by the Bridgman method, was examined in regard to the relationships among precipitation, specimen axis and misorientation of grain boundary. The results obtained are as follows:
(1) Stress corrosion cracking always occurs along (100) traces in single crystals regardless of the different heat treatments.
(2) Fracture easily occurs in the specimens with a small angle between the specimen axis and the [100] direction, because they have high normal and shear stresses to the (100) plane.
(3) The fracture time of the bicrystals is long at tilt angles of less than 10° when the twist angle and the normal and shear stresses to grain boundary are constant. On the contrary, the fracture time is almost independent of the tilt angles which are larger than 10°.
(4) The fracture time of the bicrystals is shorter in the order of the specimens quenched or aged at 220°C, non-heat treated and aged at 130°C regardless of the misorientation.
(5) When the tilt and twist angles are within 10° and the angle between the specimen axis and the [100] direction is small, transgranular cracking is recoganized along (100) traces.View full abstractDownload PDF (555K) -
Atsushi Oguchi, Minoru Otaguchi1973 Volume 37 Issue 8 Pages 922-926
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe deformability of a Fe-Al-Si alloy (Sendust) which has been considered very difficult to deform plastically was studied by the bending test and the sheath forging test at elevated temperatures of 800 to 1000°C using a cast ingot of an alloy containing about 6.44%Al, 10.32%Si, and 0.68%Ti. As for the magnetic properties, the magnetic hysteresis loop and effective permeability were examined for the alloy deformed by hot sheath forging. The results obtained are as follows: (1) By bending tests at elevated temperatures and under high hydrostatic pressures, the brittle to ductile transition temperature at atomospheric pressure and the transition pressure at room temperature were observed to be in the temperature range of 800 to 850°C and at a pressure higher than 12000 kg/cm2, respectively. (2) Using a thick-walled sheath of mild steel, the alloy was successfully deformed even at 800°C by hot forging. In the present study, the reduction in thickness more than 70% could be given on the alloy by forging at 1000°C. (3) The bending load at fracture of the alloy deformed about 72% in thickness was obtained to be about two times larger than that for the as-cast alloy. (4) The magnetic properties of the forged alloy were observed to be inferior to that of the as-cast alloy especially in the low frequency range but they were improved almost to the same order of magnitude as the cast alloy by annealing at 1000°C.View full abstractDownload PDF (394K) -
Kazuaki Fukamichi, Yuichi Suzuki, Hideo Saito1973 Volume 37 Issue 8 Pages 927-931
Published: 1973
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSInvar alloys are widely used as materials for precision instruments. The practical Invar alloys are all ferromagnetic, and the ferromagnetism of these alloys often limits the scope of their applications. In recent years, therefore, considerable attention has been directed to the research and development of nonferromagnetic Invar alloys.
Cr is antiferromagnetic material and its physical properties such as thermal expansivity and electrical resistivity change anomalously near the Néel temperature. These properties are sensibly modified by the addition of other elements. The present authors investigated the temperature dependence of the physical properties for some Cr-base primary solid solution alloys. With the addition of Sn, the Néel temperature of Cr increases up to 2.0% Sn and then decreases gradually. And the thermal expansion coefficient below the Néel temperature becomes smaller. The Néel temperature in the Cr-Fe system decreases with increasing Fe concentration, and the temperature dependence of the thermal expansivity is irregular.
Taking the above-mentioned results into consideration, the thermal expansivity and the magnetic susceptibility of the Cr-Fe-Sn alloys in the range of the primary solid solution have been measured. The results show that the alloys are of the antiferromagnetic Invar type and their susceptibility is negligibly small.View full abstractDownload PDF (422K)
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