Journal of the Japan Institute of Metals and Materials
Online ISSN : 1880-6880
Print ISSN : 0021-4876
ISSN-L : 0021-4876
Volume 43 , Issue 8
Showing 1-14 articles out of 14 articles from the selected issue
  • Hirotoshi Yamagishi, Osamu Nittono
    1979 Volume 43 Issue 8 Pages 689-695
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Ar+ ion implanted copper whiskers have been studied by means of X-ray transmission topography and X-ray triple-crystal diffractometry which were supplemented by optical microscopy and scanning electron microscopy. Copper whiskers were grown carefully by the hydrogen reduction of cuprous iodide. Ar+ ions (dose: 1012∼5×1016 ions/cm2) were implanted at room temperature with an applied voltage of 100 kV. Lattice damage caused by Ar+ ion implantation was within the surface layer of less than 1 μm in thickness. After the implantation, no surface damage was observed with a scanning electron microscope. On the contrary, X-ray topographs revealed macroscopic defects giving dotted images, together with an enhancement of background intensity. These dotted images increase in number until a fixed dose of Ar+ ions. They are probably due to clusters of microscopic lattice defects caused by Ar+ ion implantation, and they can take part in the formation of blisters at high temperatures. The reflection curves from the implanted crystals change in profile with the dose of Ar+ ions. From the analysis of the intensity profile, the lattice spacing of the implanted layer was found to be slightly larger than that of the perfect crystal. The profile change by annealing showed that the lattice strain caused by implantation was recovered over three temperature ranges, and the relaxation mechanism of lattice strain at each stage was discussed.
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  • Yasumasa Koyama, Osamu Nittono
    1979 Volume 43 Issue 8 Pages 696-701
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The thermoelastic martensitic transformation in indium rich-cadmium alloys has been examined by a phenomenological theory based on the Landau theory of phase transition. Since the cubic-tetragonal transformation in In-Cd alloys is ferroelastic, the spontaneous strain η=2(ca−1)⁄\sqrt3 is adopted as an order parameter characterizing the transition. A term proportional to η3 exists in the expression for the free energy, and the coefficients of the third and fourth order terms are assumed to be constant. Single crystals prepared by the recrystallization method are used as specimens. The axial ratio, ca, in the tetragonal phase is measured very precisely at each temperature by means of X-ray reflection topography. From the temperature dependence of the order parameter η, the coefficients of the third and fourth order terms and the other parameters are determined. Using these obtained values, the entropy change at the transition temperature, the temperature dependence of the elastic constant and the stress dependence of the transition temperature are calculated. Good agreement with experimental results is obtained. The features of the transformation behavior in both In-Cd and In-Tl alloys are discussed on the basis of thermodynamics. It is shown that the transformation in the In-Cd alloy crystal is rather of the first-order type, and that the anharmonic effect of lattice wave or the phonon instability is much stronger in In-Cd alloys than in In-Tl alloys.
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  • Shigeo Zaima, Yasuo Suzuki, Shigeki Goto
    1979 Volume 43 Issue 8 Pages 702-708
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Generally speaking, the accuracy in drilling is not so high that the drilling is often performed as a rough cutting process. Recently, however, demands for high quality of products and high machining efficiency require the improvement in drilling accuracy. Factors which affect the drilling accuracy are the properties of work materials, drilling conditions, and the accuracy and rigidity of the drilling machine, etc.
    In this paper, soft and easy deforming aluminium alloys (6063-O and 6063-F) are used for work materials so that various phenomena may become distinct. Then some experimental studies are reported mainly about the influence of reground drill shape accuracy and drilling conditions, which are the fundamental factors, on the drilled hole accuracy. The accuracy of the drilled hole is evaluated by diameter of hole, cylindrical error, hole shape, etc. The results can be summarized as follows:
    (1) The shape of drill tip has a remarkable influence on the diameter and shape of the hole, but not on the cylindrical error.
    (2) Increasing the feed deterioates the shape of hole and increases the cylindrical error. But in the case of drilling of annealed material, the margins of drill scratch the wall of hole and the effect of feed becomes complex.
    (3) Increasing the diameter of the preliminary hole reduces poth the extension of the drilled hole diameter and the cylindrical error. When the diameter of the preliminary hole exceeds 70% of that of the drilled hole, a desirable hole is obtained.
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  • Noboru Yahata, Fusao Hayama, Takeshi Inukai
    1979 Volume 43 Issue 8 Pages 708-714
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    A comparison of the wear between uni-directional and reciprocating frictions was made on a annealed 0.42%C carbon steel. Wear tests of the two sliding modes were carried out with a special designed testing machine under similar conditions of unlubricated sliding in air.
    The results obtained are as follows:
    (1) A higher wear is obtained in reciprocating friction for both metallic and oxidative wear.
    (2) The surface residual stresses induced by uni-directional friction are always more compressive.
    (3) The differences in wear for the two sliding modes can be explained in terms of the differences in the amount of abrasion by the oxidative debris, in the difficulty of plastic flow, and in the fatigue strength at the rubbing surfaces.
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  • Katsutoshi Ono, Yukitomi Ueda, Joichiro Moriyama
    1979 Volume 43 Issue 8 Pages 715-720
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Niobium and niobium alloys have received considerable attention as engineering materials for use in heat engine applications. In the past several years, the carbothermic reduction-electron beam melting combination method has made it possible to prepare the pure niobium metal. In the present investigation, the possibilities and conditions for winning pure niobium by this process have been considered with regard to the following items: (1) Working conditions and analytical results on the Nb-C-O solid solutions obtained by the carbothermic reduction of Nb2O5 in vacuum. (2) Vacuum degassing in the solid state. (3) Refining of niobium by electron beam melting. (4) Evaporation deoxidation via niobium suboxides.
    The mechanism of refining of the niobium metal by the present method can be characterized by the next steps, carbon is removed by degassing as CO and the elimination of oxygen takes place as CO as well as volatile suboxides, for instance, NbO and NbO2. Both phenomena seem to occur during the refining step in the solid state in vacuum at 2200 K and the subsequent electron beam melting. Accordingly, the carbon elimination is possible only when an excess amount of oxygen is present at the beginning of electron beam melting. On the other hand, even after carbon is lowered, the remaining oxygen can be removed by the suboxide evaporation.
    With this process the high purity niobium in which both carbon and oxygen contents are reduced to a sufficient degree could be obtained by favorable conditions of reduction and melting.
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  • Hidehiko Kamide, Hideo Sugawara
    1979 Volume 43 Issue 8 Pages 720-727
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Stress corrosion cracking (SCC) susceptibility was investigated by stress relaxation tests in a H2SO4-NaCl solution for a series of vacuum melted 18%Cr-xNi stainless steels (x=8∼30%Ni) and SUS 316 steels with varying nitrogen contents.
    As the nickel content of 18%Cr-xNi steels was increased, the time to failure increased adruptly and SCC was not observed in the steels containing 20∼30%Ni for 2500 h. The time to failure of SUS 316 steels containing 0.03∼0.18%N slightly decreased with increasing nitrogen content.
    Among the deformation structures only a strain induced α′-martensite reveals a magnetic effect. Magnetic measurements were, therefore, performed to examine the existence of α′-martensite. The permeability of the steels containing 8∼11%Ni became higher with an increase in the degree of prestraining. The same behaviour was not observed on other steels. The time to failure of SUS 316 steels, which did not show any change in permeability, depended on the degree of prestraining. Transmission electron microscopic observations showed the existence of ε-martensite in SUS 316 steels prestrained 10% in elongation. With the increased nickel content, the deformation structures of 10% prestrained specimens changed successively in the order of α′ and ε-martensites (8%Ni, 11%Ni), ε-martensite (13.87%Ni), band structure (14.06%Ni), bundle structure (20%Ni) and cellular structure (30%Ni).
    It is thought that the addition of nickel in austenitic stainless steel increases the stacking fault energy and makes the formation of strain induced martensite difficult. This should decrease the transgranular SCC susceptibility of the high Ni steels in a H2SO4-NaCl solution.
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  • Joo Ishihara, Masaichi Nagai
    1979 Volume 43 Issue 8 Pages 727-733
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    In a previous paper by the authours chipping phenomenon was described as fracture having initiated from fatigue cracks occurring from the stress concentration at the bottom of wear pits on the side surface of the blanking punches which are subjected to tensile stress by friction when pulled upwards. On the basis of this finding a laboratory test was designed where simulated chipping could be reproduced and tool steels could be assessed as to their resistance to chipping.
    When the test piece is repeatedly moved up and down while applying side-wise stress by pressing a “side-pressure piece” against its side surface, chipping phenomenon appear on the side surface of test piece. The process of this phenomenon are as follows.
    (1) Numerous wear pits appeared on the side surface. Fatigue cracks are initiated at their bottom and grow as fracture. The phenomenon is thought as being essentially identical to that observed on the punches in actual operation.
    (2) A test was conducted on SKD-1 steel and a quantitative relation between the side-wise stress and the tool life was obtained.
    (3) The proposed method was found satisfactory as a test of tool steels for blanking punches with respect to their chipping resistance.
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  • Joo Ishihara, Masaichi Nagai
    1979 Volume 43 Issue 8 Pages 734-740
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The present study was undertaken to investigate the chipping behaviour frequently found on blanking punch, since no systematic research about this behaviour has been established. The punches made of SKD-1 steel were used to reproduce the chipping-phenomena by simulation. The punches, after this test, were examined by means of electron fractography and optical microscopy.
    (1) The critical limit value of side direction stress to occur the chipping-fracture is exist.
    (2) This critical limit value depends on hardness of punch.
    (3) Life time of punch is depends on hardness of punch and with value of side direction stress.
    (4) On the case of low side stress, many small fatigue cracks joined with each other and grow up the long crack, and chipping fracture results from the crack growth. But on the case of havy side stress, a small fatigue crack immediately grow to the chipping fracture.
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  • Kichinosuke Hirokawa, Masaoki Ohu
    1979 Volume 43 Issue 8 Pages 741-744
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    An analytical potentiality of a glow excitation for elements in some binary alloys was studied in comparison with a high voltage spark discharge. The alloys adopted were Al-Si, Al-Ni and Fe-C alloys. With these alloys the linear relationship between the concentration ratio and the light intensity ratio of alloying elements was obtained except for the hyper eutectic phase of Al-Si alloys.
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  • Kazuhiro Teramoto, Michinori Takano
    1979 Volume 43 Issue 8 Pages 744-752
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Stress corrosion crack velocity (dadt) under the slow extention rate condition has been determined for commercial Type 304 austenitic stainless steel in boiling 42%MgCl2 solution at 143°C. The test specimens were 2.5 and 5 mm thick with round notch.
    A single crack length was measured by a traveling microscope (×60) in the crosshead speed (CS) range 4×10−5 to 1×10−2 mm/min. Slip lines on the tested specimen surface were examined by a dfferential-interference microscope and the fracture surfaces of all tested specimens were also observed by a scanning electron microscope.
    Specimens showed a single transgranular cracking in the CS range of 4×10−5∼4×10−3 mm/min. The initial crack propagation rate (dadt) increased with CS in 2.5 mm thick specimens and dadt also increased with crack length at any constant CS when a single transgranular cracking occurred. On the other hand, in 5 mm thick specimens, the dependence of dadt on CS or crack length was not so clear as seen in 2.5 mm thick ones. Whenever a single transgranular cracking was observed, the maximum value of dadt was around 10−2 mm/min.
    These dependences of dadt on CS, crack length and the thickness of specimen have been discussed from the view point of the formation rate of slip steps and the corrosion rate of metals in slip steps. The relationship between dadt obtained in fracture mechanics by other investigators and those in this study has also been discussed.
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  • Hiroaki Shinto, Yoshihiro Saito, Michihiko Ayada, Kenzo Kato
    1979 Volume 43 Issue 8 Pages 753-759
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The recovery strain during unloading in the tension test has been measured by strain gauge in the range from 0 to 3% tensile prestrain for sheet metals including 18-8 stainless steel, aluminum, aluminum alloys, copper, 7:3 Brass, zinc and titanium in the annealed and temper rolled state.
    The relation between the recovery strain and tensile prestrain (or prestress) and the influence of temper rolling on this relation are discussed.
    The recovery strain εR increases with increasing tensile prestrain in all metals tested. The ratio of εR to elastic strain σFE estimated by prestress σF divided by Young’s modulus E is greater than unity and amounts to about 2.6 in zinc, 1.6 in 7:3 Brass, 1.4 in 18-8 stainless steel and 1.2 in copper, titanium, aluminum and aluminum alloys. By temper rolling εR increases in all metals tested, while recovery-strain-to-elastic-strain ratio tends to decrease in copper, aluminum and 7:3 Brass, but increases in 18-8 stainless steel.
    The following relation is found to exist for all metals between εR and elastic strain σFE:
    (This article is not displayable. Please see full text pdf.)
    \ oindentwhere k and σ0 are constants depending on the material and its process history.
    Finally εR is found to have good correlation with the shape of product by cold roll-forming.
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  • Shigeo Matsushima
    1979 Volume 43 Issue 8 Pages 759-765
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Temperature dependences of tensile strength σB and cyclic tensile fatigue strength for bcc and fcc Fe at high temperature in vacuum have been studied. The results obtained are as follows:
    (1) Relations between σB and testing temperature T except for the range of 900∼1000°C are given by
    (This article is not displayable. Please see full text pdf.)
    \ oindentwhere \barσB, β and T0 are 177.3 MPa, −4.48×10−6°C−2 and 100°C for bcc Fe, and 13.2 MPa, −5.80×10−6°C−2 and 910°C for fcc Fe.
    (2) Relations between fatigue life N and maximum value σ0 of cyclic tensile stress are given by
    (This article is not displayable. Please see full text pdf.)
    \ oindentwhere N0 and B are 80 and 13 for bcc Fe, and 500 and 9 for fcc Fe.
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  • Jin Onuki, Kô Soeno, Masateru Suwa
    1979 Volume 43 Issue 8 Pages 765-769
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    Al and Cu casting alloys were produced with variations in quantity (0∼24 vol%) and size (177∼900 μm) of graphite particles and in matrix composition in order to determine their effect on the damping capacity. The damping capacity Q−1 of graphite-dispersed Al and Cu casting alloys has been investigated in transverse vibration in the temperature range from room temperature to 150°C. The results obtained are as follows. (1) The damping capacity Q−1 of graphite-dispersed Al and Cu casting alloys increases with increasing graphite content and this is independent of matrix composition. (2) Al casting alloy containing 23 vol% graphite and Cu casting alloy containing 16 vol% graphite exhibits damping capacity Q−1 of 6×10−3 and 4×10−3, respectively. (3) The damping capacity Q−1 of Al and Cu casting alloys depends on the graphite size and increases as the graphite size increases. (4) The temperature dependence of the damping capacity Q−1 in graphite-dispersed Al and Cu casting alloys is small.
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  • Kenzo Kon, Shigeo Tsujikawa, Yoshihiro Hisamatsu
    1979 Volume 43 Issue 8 Pages 770-775
    Published: 1979
    Released: April 04, 2008
    JOURNALS FREE ACCESS
    The characteristics of stress corrosion cracking (SCC) of type 304 steel single crystal were investigated in H2SO4-NaCl solution with reference to faceting dissolution and the crystallographic plane of the fracture surface in the two potential zones: I (near the corrosion potential) and II (active-passive transition region). The kinds of facet change in the order of {100}→{100}+{111}→{111} in 1N-H2SO4+0.5M-NaCl solution, and change in the order of {110}→{110}+{100}→{100}+{110}+{111} in 5N-H2SO4+0.5M-NaCl solution with an increase in potential from the corrosion potential to the active-passive transition potential. At the potential of zone I in 5N-H2SO4+0.5M-NaCl solution, cracks are found mainly to initiate at the traces of {110} with large normal stress (σ) and shear stress (τ), and to propagate along {110} in the crystal. On the other hand, at the potential of zone I in 1N-H2SO4+0.5M-NaCl solution, cracks mainly nucleate at the traces of {110} with large σ and τ, and propagate along {100} in the crystal. At the potential of zone II in both solutions, {111} faceting dissolution occurs over all specimen surfaces, and cracks are rarely found. Since the crystallographic plane {hkl} of the fracture surface in zone I corresponds to the slowest dissolution plane {hkl} under the above condition, there is an important relationship between SCC and {hkl} faceting dissolution.
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