Journal of the Japan Institute of Metals and Materials
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
Volume 33 , Issue 5
Showing 1-23 articles out of 23 articles from the selected issue
  • Genjiro Mima, Sigenori Hori, Sigeoki Saji, Yukiyoshi Tominaga
    1969 Volume 33 Issue 5 Pages 521-526
    Published: 1969
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    A solution-treated specimen and four kinds of aged specimens of Cu-2.3 wt%Fe alloy, containing spherical coherent precipitates with smaller diameters than 430 Å, were cold-rolled 93.3%. The effects of the precipitate particles on the softening behaviour during isochronal annealing were studied by hardness measurement, and optical and transmission electron microscopy. The results obtained were summarized as follows. The hardness of this alloy increases remarkably and non-ferromagnetic γ-precipitates in the aged specimens transform to a ferromagnetic α-phase and lose coherency with the matrix by 93.3% cold-rolling.
    The softening of the aged specimens proceed gradually during annealing after rolling and the softening rates were much slower than that of the solution-treated specimen. The temperatures for 50% hardness drop in the aged specimens were higher than that of the solution-treated specimen by about 410°∼470°C.
    The differences of the softening rates among the aged specimens are small, but the softening rate of the specimen containing precipitate particles with a diameter of about 430 Å, is lower than that of the other specimens.
    The formation and the growth of recrystallization nuclei during annealing in the aged and rolled specimens proceed preferentially in the area with no or a few precipitate particles.
    It appears that the precipitate particles in the aged and rolled specimens retard the movement of dislocations, subgrain boundaries, recrystallized grain boundaries and old grain boundaries in the process of recovery and recrystallization.
    Recovery and recrystallization of the solution-treated and rolled specimen during annealing almost complete before precipitate particles come to reveal a retardation effect.
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  • Genjiro Mima, Masaharu Yamaguchi, Yukichi Umakoshi
    1969 Volume 33 Issue 5 Pages 527-530
    Published: 1969
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The very early stage of ageing of Al-40 at%Zn alloy around 290°C has been investigated by means of electrical resistivity measurements, hardness tests and transmission electron microscopic observations. The results are summarised as follows:
    (1) Electrical resistivity change during ageing around 290°C suggests that there is a considerable difference between the ageing behaviours at high and low temperatures.
    (2) Hardness of the alloy increases at the very early stage of ageing, passes through a maximum, and decreases rapidly.
    (3) In the very early stage of ageing, a fine grid-like structure can be observed by transmission electron microscopy, and this fine grid-like structure is very similar in appearance to the modulated structure formed due to the occurrence of spinodal decomposition. The increase in hardness at the very early stage of ageing seems to be associated with the formation of the fine grid-like structure.
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  • Genjiro Mima, Sadatoshi Inada, Kiyoshi Sakamaki
    1969 Volume 33 Issue 5 Pages 531-536
    Published: 1969
    Released: April 04, 2008
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    Over a strain rate range from 10−4 l/s to 103 l/s, tensile properties of a low carbon steel were investigated at −196°∼500°C. The results obtained are summarized:
    (1) The temperature of blue-brittleness shifts to a higher temperature range with increase in strain rate, and the strain rate range at which blue-brittleness occurs widens with elevated temperatures. And the mechanism of blue-brittleness at higher temperatures is different from that at lower temperature.
    (2) The lower yield stress and the tensile strength are expressed in terms of four strengths determined by the temperature and the strain rate at a certain grain size;
    (This article is not displayable. Please see full text pdf.)
    where σ1, σ2, σ3 and σ4 are the strength without ageing, the strength increment induced by strengthening with deformation, the strength decrement induced by softening and the strength increment with blue-brittleness, respectively.
    (3) At lower temperatures, elongations are considerablly small in spite of sufficient area contractions at higher strain rates because of the existence of a quasi-critical impact velocity.
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  • Tsuneo Shirai, Hiroyuki Kodera, Saburo Yanagisawa
    1969 Volume 33 Issue 5 Pages 536-541
    Published: 1969
    Released: April 04, 2008
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    An automatic gas analyser with a diaphragm micromanometer which is controlled by selecting the paths of gases with magnetic solenoid mercury cuts using time-switches was designed for analysis of gases in metal.
    Oxygen and nitrogen in the standard steel samples were analysed by this analyser, and the percent standard deviations were 1.2 and 1.5 for oxygen and nitrogen, respectively.
    This apparatus was also applied for the analysis of gases less than pphm in metallic zirconium and high purity silicon.
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  • Toru Yokoyama, Takashi Takezawa, Yoshisuke Higashida
    1969 Volume 33 Issue 5 Pages 541-546
    Published: 1969
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    In 1943, Kaya and Sato measured the specific heat of a FeCo superlattice alloy and observed a bump in the specific heat versus temperature curve at 550°C in addition to the order-disorder transformation at 730°C. Such a bump cannot be seen in the theoretical specific heat versus temperature curve for ordinary superlattice alloys. Despite numerous works that followed, the reason for this phenomenon has not been fully explained.
    In the present study the following procedure was employed: In heating the slowly cooled ordered FeCo alloy, the specimen was kept at a predetermined temperature for a sufficient time, so that the electrical resistivity could be retained constant. Then the specimen was submerged into water several times and its electrical resistivity was measured in liquid nitrogen. This process was repeated several times at different temperatures up to 800°C.
    In cooling the specimen, the same procedure as mentioned above was employed in a reverse direction.
    In the equilibrium electrical resistivity versus quenching temperature curves thus obtained, the anomaly near 550°C cannot be seen which has been reported by some workers. When the temperature of the specimen is changed, it takes a certain time until equilibrium in the ordered degree is reached. This is considered as the cause of the anomaly in specific heat of FeCo alloy.
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  • Kazuyoshi Shimakage, Tetuo Miyazaki, Susumu Morioka
    1969 Volume 33 Issue 5 Pages 547-552
    Published: 1969
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    It is well known that the mechanism of the reduction of oxides with gas depends often on the experimental conditions chosen. By the use of synthetic nickelferrite, the effect caused by the shape of samples on the reduction with hydrogen gas and the reduction process in the case of the hydrogen reduction of nickelferrite have been studied in the current investgation. The weight changes were measured by a thermobalance and the reduction process of nickelferrite was estimated from the data by an X-ray diffractometer. The experimental results obtained are summarized as follows: The fractional reduction, R, of nickelferrite increased parabolically with increasing of the time of the reduction. Furthermore, the function which is commonly used for the case of the reaction controlled by the interfacial areas, 1−(1−R)1⁄3, was proportional to the time of the reduction in the range from 0 to 82% reduction. The shape effect for the reduction mechanism was not so significant in the case of the hydrogen reduction of nickelferrite at 700°C. From the data of X-ray diffraction analysis, it is considered that the hydrogen reduction process of nickelferrite at 700°C may proceed in the order of the following three steps; 3NiFe2O4→3Ni+2Fe3O4, Fe3O4→3FeO, FeO→Fe.
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  • Hitoshi Nakae, Noriaki Gosi
    1969 Volume 33 Issue 5 Pages 553-557
    Published: 1969
    Released: April 04, 2008
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    The effects of sulphur on the recrystallization of cold rolled 3.17%Al-Fe alloy sheets were investigated on the specimens with three different sulphur contents.
    On primary recrystallization, the main component of the texture transformed from (100)[001] to (110)[001] with increasing sulphur content, where the latter was the same as the case of a 3.25%Si-Fe alloy sheet.
    On secondary recrystallization, (100)[001] and (110)[001] components in the lower sulphur contents and (100)[001] component in the higher sulphur contents developed dominantely by consuming the matrix of the (111)[11\bar2] component.
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  • Shozo Yoshioka, Yutaka Nakayama, Taichiro Ito
    1969 Volume 33 Issue 5 Pages 557-561
    Published: 1969
    Released: April 04, 2008
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    The effects of heat treatment on the yield stress, the stress-strain relationship, the deformation mode and the dislocation structure were studied in the alloy whose composition was close to the stoichiometric Cu2NiZn. Some of the specimens were initially water quenched from 800°C and then deformed in tension. The others were deformed after annealed at various temperatures.
    The results obtained are as follows:
    (1) The yield stress reaches a maximum at 300°∼400°C annealing and then decreases rapidly by annealing at temperatures above 400°C.
    (2) The stress-strain curves for the quenched single crystals exhibit the prolonged stages I and II. The deformation proceeds by the propagation of Lüder’s band. On the other hand, the specimens annealed at 300° and 400°C show a high work hardening rate from the beginning of deformation. The behavior of yield stress after annealing resembles that for polycrystallines.
    (3) Slip lines of the quenched single crystals are coarse and dislocations are arranged in the piled-up arrays. On the contrary, slip lines of the annealed specimens are extremely fine, and dislocations are distributed rather uniformly and contain many secondary dislocations.
    (4) In the specimens annealed at 300° and 400°C, dislocation pairs, i.e. super lattice dislocations, are observed. The separation of pairs decreases as the annealing time increases.
    (5) From these results, it is confirmed that the long range order is introduced by annealing of this alloy.
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  • Shozo Yoshioka, Yutaka Nakayama, Norio Hosokawa
    1969 Volume 33 Issue 5 Pages 562-565
    Published: 1969
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The size and shape of G.P. zones in Al-Zn alloys were studied by means of the X-ray small angle scattering technique and transmission electron microscopy, and the following results were obtained.
    (1) The shape of G.P. zones was changed from spherical to ellipsoidal when their radii exceeded about 32 Å.
    (2) The ellipsoidal G.P. zones had long axes which were parallel to the ⟨111⟩ direction. The dimensions of G.P. zones were 32∼35 Å in short axis and 32∼150 Å in long axis, when the specimens were aged at room temperature.
    (3) The size of G.P. zones in the quenched specimens were distributed fairly uniformly, but not so in the air-cooled specimens.
    (4) When heated at high temperatures, the size of G.P. zones in the aged specimens becomes larger and the shape became ellipsoidal. The sizes of ellipsoidal G.P. zones were 35∼70 Å in short axis and 150∼500 Å in long axis. But no G.P. zones were observed after heating for 2 minutes at 150°C.
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  • Shozo Yoshioka, Yutaka Nakayama, Norio Hosokawa
    1969 Volume 33 Issue 5 Pages 566-570
    Published: 1969
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The yield stresses of Al-Zn single crystals containing G.P. zones were measured at 77°K as functions of the solute concentration and the size of G.P. zones. It was found that the solute concentration dependence of the yield stress was in good agreement with the theory of the stacking fault strengthening mechanism, but the zone size dependence of the yield stress did not agree with any theories.
    The various models proposed for zone-hardening were compared with the experimental results, and the hardening model for Al-Zn alloys should be the one in which the attractive force acts between the zones and the dislocations. In this model, there are two cases in which the shear modulus or the stacking fault energy are different between the matrix and the zones.
    The difference in the shear modulus could not account for the zone size dependence of the yield stress. It is found that the stacking fault strengthening is the zone hardening mechanism in the present case, but to account for the zone size dependence of the yield stress, it should be considered that the effective stacking fault width is smaller than the value calculated by Hirsch.
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  • Jun Fujiwara, Nobuhisa Matano
    1969 Volume 33 Issue 5 Pages 571-575
    Published: 1969
    Released: April 04, 2008
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    Applying the argon carrier gas fusion-electric conductivity difference method for the determination of oxygen in iron alloys with high sulfur contents, the effect of sulfur in the sample on the determined values of oxygen was investigated.
    The evaporated gases in the graphite crucible with the melted sample were analyzed by gas chromatography, and carbon disulfide and carbonylsulfide was detected.
    Carbon disulfide was decomposed perfectly with cupric oxide, and partial decomposition of carbon disulfide and carbonylsulfide was carried out with iodine pentoxide.
    The oxygen in iron alloys with high sulfur contents was determined by the argon carrier gas fusion-electric conductivity difference method with the adsorption colunm of molecular sieve 13X, and satisfactory results were obtained.
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  • Toshirô Suhara, Shigehisa Fukuda, Hiroshi Itô, Hiroki Fuku ...
    1969 Volume 33 Issue 5 Pages 576-581
    Published: 1969
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The present report is related to the newly developed metallic spraying method by means of wire explosion.
    In this report the surface roughness, hardness, component, structure and adhesion strenghth, etc. of spray coating of various metals by this spray method are investigated.
    The results obtained are summarized as follows:
    (1) The surface of spray coatings is smooth and RMS is 1∼5 μ. It shows small value as compared with RMS of 75∼125 μ in plasma flame spray.
    (2) The hardness of spray coating of cemented carbides is lower than that of base materials.
    But in other case, the hardness of spray coatings is higher.
    (3) The components of cemented carbides (WC-Co system) in spray coating mainly consist of W2C and Co. The carbon content in a steel shows a decrease of about 30% after spraying.
    (4) The adhesion strength is high, but it depends on the combinations of spray metals and base metals. In the case of using Cu as base materials, the adhesion strength is not so high. In the case of mild steel and brass it is as large as more than 200 kg/cm2.
    (5) By optical microscopy and electron microscopy, it is ascertained that the spray coatings are comparatively compact, and adhesion is satisfactory.
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  • Kunio Shiobara, Susumu Morioka
    1969 Volume 33 Issue 5 Pages 581-587
    Published: 1969
    Released: April 04, 2008
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    In order to know the electrochemical behaviours of Ti in the crevice, the weight loss, corrosion potential and galvanic current were measured for Ti in the crevice and on the open surface in boiling acid NH4Cl solution. Also, anodic polarization measurement for Ti in the crevice and on the open surface was conducted in boiling acid and neutral NH4Cl solutions. The results obtained were as follows.
    In boiling acid NH4Cl solution containing a small amount of the oxidizing agent, titanium undergoes crevice corrosion in narrow gaps at points of contact with nonmetallic materials due to the depletion of the oxidant in the crevice.
    In acid and neutral solutions containing more than 5 N NH4Cl, the current of Ti in the passive region in the crevice was much higher than that of Ti on the open surface, and a granular corrosion product mainly composed of TiO2 (rutile) was observed after anodic polarization measurement.
    In anodic polarization of Ti in the crevice in boiling 5 N NaCl solution, a similar phenomenon to that in NH4Cl solution was observed, but not in Na2SO4 solution. Potential decay curves indicate that the corrosion product of Ti in the crevice in chloride media is less stable and easily activated than that of Ti on the open surface.
    The results mentioned above suggest that the passive film formation is hindered and oxychloride TiOxCly is formed on Ti in the crevice in boiling neutral solution with higher Cl ion concentration (5 N, 10 N) due to the depletion of H2O in the crevice, promoting crevice corrosion.
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  • Kazuhiko Asano, Ken-ichi Hirano
    1969 Volume 33 Issue 5 Pages 587-593
    Published: 1969
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Prolonged ageing behaviors in an Aluminum-5.06 wt% Zinc-0.94 wt% Magnesium alloy at 100°C have been investigated by the specific heat measurements and tensile tests. A large heat effect arising from the G.P. zones has been observed even after ageing for 10000 hours at 100°C. On the contrary, only a small energy change due to the intermediate precipitate has been detected.
    Remarkable age-hardening has been observed. The maximum strength (0.2% proof stress) of about 24 kg/mm2 was obtained after ageing for 500 hours. The strength has decreased to the as-quenched value by heating at 250°C for 30 seconds (reversion), even after ageing to the maximum strength.
    The serrated stress-strain curve has been obtained in the early stage of the ageing. This has been correlated to the age-hardening characteristics of the alloy.
    The metastable equilibrium with respect to the zone and the role of the zone in the age-hardening has been discussed.
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  • Hakaru Masumoto, Hideo Saitô, Shôhachi Sawaya
    1969 Volume 33 Issue 5 Pages 593-595
    Published: 1969
    Released: April 04, 2008
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    The thermal expansion coefficient and the temperature coefficient of Young’s modulus of nickel-copper alloys have been determined with a vertical dilatometer previously designed by one of the present authors and by means of a vibrator-controlled oscillator system, respectively. And it has been found that the mean linear thermal expansion coefficient (0°∼40°C) vs. composition curve is convex in the ferromagnetic range and concave in the paramagnetic range against the composition axis and also the mean temperature coefficient (0°∼40°C) of Young’s modulus shows negative values in the whole composition range of the alloys except the maximum value of +2.1×10−5 in the alloy containing 29.85%Cu.
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  • Namio Ohtani, Yoshio Fujishima
    1969 Volume 33 Issue 5 Pages 596-601
    Published: 1969
    Released: April 04, 2008
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    The growth process of etch pits on the surface of Al-1%Cu alloy was studied in mixed solutions of NaF, HCl and HNO3. The results obtained are as follows:
    (1) Although pits grow rapidly, they stop to grow very rapidly by forming a protective film in them.
    (2) Usually crystal planes, such as {111} and {100}, tend to dissolve and appear predominently, but {110} plane does not appear so often when no stress is applied to the alloy.
    (3) The electropolishing mechanism seems to exist in the pit growth process especially at the noble potential.
    (4) Etch pits tend to grow to macropits and to be hemispheres by electropolishing in the noble range of potentials when the dissolution current density is large and the ion-condensed layer may be formed in pits.
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  • Tshio Kainuma, Ryoji Watanabe
    1969 Volume 33 Issue 5 Pages 602-606
    Published: 1969
    Released: April 04, 2008
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    The precipitation hardening behavior of Ni-2.5 wt%Be alloy has been investigated by means of hardness measurement, electrical resistivity measurement, and optical and transmission electron microscopy.
    The results show that the precipitation sequence of this alloy is α (supersaturated solid solution)→G.P.zone→β′ (metastable phase)→β (stable phase).
    The grain boundary reaction type of precipitation occurs at the grain boundary.
    The high age-hardenability of the alloy is found to be caused by the formation of the G.P.zones and the metastable phase. The overageing of the alloy is due to the precipitation of the grain boundary reaction type and the coalescening of the Widmanstätten type precipitates.
    The slow rate of decrease in electrical resistivity during the initial stage of the ageing is attributed to the formation of the G.P.zones and the metastable phase, and the rapid decrease, to the precipitation of the grain boundary reaction type or the Widmanstätten type.
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  • Tokuzou Tsujimoto, Masao Adachi
    1969 Volume 33 Issue 5 Pages 606-611
    Published: 1969
    Released: April 04, 2008
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    Melting points and cast structures of titanium (>15 wt%)-aluminium (<55 wt%)-cobalt (<70 wt%) ternary alloys were examined, and reactions with melt were discussed. The results obtained are as follows:
    (1) Two ternary compounds (Ti, Al)Co and Ti1+xAl2−xCo (0≤x≤1) (θ phase) are observed.
    (2) Two pseudo-binary systems, θ-(Ti, Al)Co with the pseudo-peritectic reaction and θ-TiAl(γ) with the pseudo-eutectic reaction, are observed.
    (3) The following four invariant reactions with melt exist in order from the higher temperature reaction;
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  • Tokuzou Tsujimoto, Masao Adachi
    1969 Volume 33 Issue 5 Pages 612-617
    Published: 1969
    Released: April 04, 2008
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    The structures of titanium (30∼87 wt%)-aluminium (<60 wt%)-cobalt (<60 wt%) alloys have been examined by optical microscopy and X-ray diffraction analysis, after annealing in the range 600°∼1300°C. Isothermal sections of the ternary system for this range have been established, and a partial titanium-aluminium-cobalt ternary diagram containing >30 wt% titanium has been proposed in consideration of the experimental results on reactions with melt in the titanium-rich region and a reaction in solid in the titanium-rich corner of this system. The invariant reactions in this system are as follows:
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  • Mitsuhisa Hino, Tatsuhiko Ejima, Mitsuo Kameda
    1969 Volume 33 Issue 5 Pages 617-622
    Published: 1969
    Released: April 04, 2008
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    The surface tension, density and viscosity of PbO-K2O-SiO2 ternary melts have been measured in the temperature range 800° to 1200°C by the use of the dipping cylinder method, the Archimedean method and the counter-balanced-sphere method, respectively.
    In the (PbO·SiO2)-K2O pseudo-binary system, the surface tension decreases with the addition of K2O. The temperature coefficient of surface tension changes from the negative to the positive sign with increasing amount of K2O. This characteristic phenomenon may be explained in terms of the production of a homopolar Pb-O bond in the melt with the addition of K2O.
    The negative deviation from the additivity in molar volume and the decrement of viscosity with the addition of K2O indicate the bond breaking of SiO2 network and the production of descrete anions.
    The apparent activation energy for viscous flow decreases with increasing content in the K2O in (PbO·SiO2)-K2O system. For the (PbO·SiO2)-(K2O·SiO2) pseudo-binary system, the activation energy shows a minimum value at about 10 mol%K2O.
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  • Hisashi Suzuki, Takaharu Yamamoto, Ichiro Kawakatsu
    1969 Volume 33 Issue 5 Pages 623-628
    Published: 1969
    Released: April 04, 2008
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    The 18-8 type stainless steels are known as materials difficult to machine. The causes and counter-measures, however, have never been studied in relation to the metallurgical factors of cemented carbides. Therefore, the wear processes of WC-TiC-10%Co alloy tools in the cutting of stainless steels were investigated with particular attention to the grain size of WC and β phases, and carbon content, titanium carbide and impurity contents.
    The main results obtained were as follows:
    (1) Different mechanisms between cratering wear and outside wear were found to exist, and clearance wear was caused by the plastic deformation of the tools.
    (2) With increasing titanium carbide content, cratering wear, plastic deformation and clearance wear were all decreased with the exception of outside wear.
    (3) In the case of high speed cutting, low carbon WC-10%TiC-10%Co alloy tools showed better resistance to all the wears than high carbon alloy tools. With increasing grain size of the β phase and decreasing grain size of the WC phase, the resistance to cratering and clearance wears was highly improved.
    (4) In sum, it was found that the WC-TiC-Co alloy tools showing high resistance to the various wears in high speed cutting of stainless steels, should be developed in the alloys with low carbon content, fine grain size of WC and coarse β phases. These results may be applied to WC-TiC-TaC-Co alloy tools.
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  • Hisashi Suzuki, Motohiro Kanno, Ichiro Kawakatsu
    1969 Volume 33 Issue 5 Pages 628-633
    Published: 1969
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The reasons why the strength of Cu-Zr-Cr alloys is superior to those of Cu-Zr and Cu-Cr alloys were investigated in relation to their aged structures by transmission electron microscopy. Three sorts of alloys, i.e., Cu-0.54%Zr-0.50%Cr, Cu-0.30%Zr and Cu-0.26%Cr alloys, were used in this study. In each alloy, specimens in the state of solution-treatment at 950°C and of cold-working by 83% after solution-treatment were prepared. Each specimen was vacuum-aged at various temperatures up to 700°C.
    The results obtained were as follows:
    (1) Under the same aging condition, two sorts of precipitates in Cu-Zr-Cr alloy, i.e., Cu3Zr and Cr, were finer and more densely distributed than the individual precipitate in each binary alloy, leading to the higher strength of the ternary alloy.
    (2) The sequense of precipitation of the two sorts of precipitates corresponded to that of the precipitate in the binary alloys. Modes of precipitation were heterogeneous and homogeneous in the Cu-Zr and Cu-Cr alloys, respectively.
    (3) In cold-worked state, the precipitate of Cu3Zr stabilized the worked structure of the Cu-Zr-Cr alloy due to preferential precipitation on the cell-walls in the same way as in the Cu-Zr alloys.
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  • Ichiro Morimoto, Mitsunori Sato, Masayuki Hijikata
    1969 Volume 33 Issue 5 Pages 633-638
    Published: 1969
    Released: April 04, 2008
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    The switching and sliding characteristics of Ag-C mixtures produced by carbonization of several resins such as vinyle, furan and phenol have been measured. The results obtained are as follows:
    (1) The carbonized Ag-C mixtures have high resistance to erosion for switching and sliding contacts. Particularly, the Ag-C mixture produced by carbonization of vinyle chloride resin has excellent resistance to erosion and stability, the amount of erosion is one-fifth and one-tenth that of the sintered Ag-graphite mixture for switching contact and for sliding contact respectively. This may be due to the presence of AgCl which is produced by the reaction of decomposed chlorine and silver.
    (2) The hardness of the carbonized Ag-C mixtures is higher than that of sintered Ag-graphite mixtures. The carbon is homogeneously dispersed and the rate of crystallization of the carbon depends on the carbonization temperature.
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