All issues
Volume 42, Issue 1
Displaying 1-17 of 17 articles from this issue
- |<
- <
- 1
- >
- >|
-
Joo Ishihara, Masaichi Nagai, Hiromi Kagohara, Yasushi Ouchi1978 Volume 42 Issue 1 Pages 1-7
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe present study was undertaken to find the cause of chipping frequently found on blanking-punch, since little had been known about the relation between wear, stress, chipping and materials on the punch. The stress on the operating punch was measured and the stress distribution in the punch was calculated by computer simulation using the measured values.
The results were summarized as follows: When SUS 304 type stainless steel sheet of 2 mm thickness was stamped out by 15 mm punching with a 5% clearance, the peak pressure stress in the axial direction of about 170 kg/mm2 appeared on the side surface near the edge of the punch. In this case, owing to this pressure stress, it is unknown whather fatigue took place or not. When a SPCC steel sheet of 2 mm thickness was stamped out by 15 mmφ punching with a 5% clearance, the peak pressure stress of about 55 kg/mm2 in the axial direction appeared on the side surface near the edge of the punch. The value was below the fatigue limit of the tool steel. Therefore, in this case, chipping was likely to occur not in the pulling-up process. In the pulling-up process, if the side surface of punch had no adhesion and no wear-pits, the peak stress value was below the fatigue limit of the tool steel. If wear-pits or adhesion, appear in the side surface of the punch, the stress increase above the fatigue limit of the tool steel, and chipping was likely to occur.View full abstractDownload PDF (558K) -
Masateru Suwa, Kô Soeno1978 Volume 42 Issue 1 Pages 8-13
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSCopper alloys containing the hard phase would be expected to have high wear resistance. In this study, the wear of Cu, Cu-Sn, Cu-Zn and Cu-Al alloys with and without Mn5Si3 (hard phase) has been investigated. Manganese silicide (Mn5Si3) is formed in the solidification of copper alloys containing Mn and Si. The results obtained are summarized as follows:
(1) In hypoeutectic, wear is increased by the existence of eutectic Mn5Si3 particles. It is considered that the decrease in wear resistance is attributed to eutectic Mn5Si3 which plays the role of crack propagation source after being transfered from the metal matrix to sliding surface as a result of the plastic flow of the matrix.
(2) In hypereutectic, wear resistance is increased by the existence of primary Mn5Si3 crystals. It is suggested that the primary Mn5Si3 crystals play a role of piles which suppress the plastic flow of the metal matrix and its adhesion to an opponent.View full abstractDownload PDF (749K) -
Mitsumasa Kishida, Kenzo Igaki1978 Volume 42 Issue 1 Pages 13-18
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe effects of temperature on the electrophoretic behaviour of Co (II), Cu (II), Fe (III), and Ni (II) complex ions in hydrochloric acid solutions were investigated by column electrophoresis with silica gel powder as support medium. Electrophoretic velocity of the complex ion was determined by measuring the center position of the migrating zone.
With increasing temperature from 3°C to 82°C, for Co (II), Cu (II), and Fe (III) complex ions, the zone first migrates towards the cathode, and then reverses towards the anode for the intermediate hydrochloric acid concentration. For Ni (II) complex ion migration is always towards the cathode in the range of temperature and hydrochloric acid concentration studied.
These results can be explained by the predominant formation of higher chloro-complexes at higher temperatures.View full abstractDownload PDF (519K) -
Mitsumasa Kishida, Kenzo Igaki1978 Volume 42 Issue 1 Pages 18-25
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe charges for chloro-complex ions of some transition metals were estimated from electrophoretic measurements on solution of hydrochloric acid in the concentration range 1 N to 10 N and the temperature range 3°C to 82°C.
With increasing hydrochloric acid concentration, the average charges of the Co (II), Cu (II), Fe (III), and Ni (II) complex ions decrease gradually from +2 to −2, +2 to −2, +1 to −1, and +2 to +0.5, respectively. The charges of the Co (II), Cu (II), and Fe (III) complex ions decrease with increasing temperature and change sign from positive to negative for the intermediate hydrochloric acid concentration. The charge of the Ni (II) complex ion decreases also with increasing temperature but does not change sign.View full abstractDownload PDF (741K) -
Katashi Masumoto, Nobuyuki Koguchi1978 Volume 42 Issue 1 Pages 25-32
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe p-HgCr2Se4/n-CdIn2S4 heterojunction was prepared by the method of closed-tube vapour phase epitaxial growth using 1.5 mol%Ag doped HgCr2Se4 single crystal as the substrate, CdIn2S4 powder as the source material and I2 as a transport agent.
The constituents containing in the HgCr2Se4-CdIn2S4 heterojunction varied abruptly at the interface within the resolving power of EPMA; however, Hg and Cd only are mutually replaced with one another to a certain depth in the direction from the junction interface toward the HgCr2Se4 interior and the inside of the CdIn2S4 epitaxial layer. Although these mutual replacement depths do not depend on the substrate temperature and the temperature difference between the growth and the higher temperature ends, they depend strongly on I2 concentration. To be more precise, the smaller I2 concentration, the thinner are the mutual replacement regions. The existence of the mutual replacement regions was confirmed by measurement of the photovoltaic property.
The long wavelength edge of the photoresponse for the p-HgCr2Se4/n-CdIn2S4 heterojuction diodes devoid of this mutual replacement regions showed a red shift, indicating that the red shift is in good agreement with the temperature dependence of the optical absorption edge of HgCr2Se4.View full abstractDownload PDF (821K) -
Noboru Yahata, Fusao Hayama1978 Volume 42 Issue 1 Pages 32-40
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSFor 0.42%C and 0.87%C carbon steels wear experiments were carried out with a pin-on-ring type wear testing apparatus in white spindle oil. Metallurgical structures, oxidation, hardening and residual stresses were examined by optical and electron microscopy and X-ray and EPMA techniques in the surface layers during the steady wear process, and the relation between wear rates and those properties was discussed.
The results obtained are as follows:
(1) The wear situation can be divided into two forms; one is always mild wear from the starting of sliding, and the other changes from severe to mild wear. The severe wear is due to the seizing.
(2) In the case of the change from severe to mild wear, continuous hard layers occur on all the frictional surfaces.
(3) Fine cracks and pits brought about by fatigue are observed in the continuous hard layers.
(4) In white spindle oil the specific wear of both carbon steels decreases by a factor of 102∼104 and this change with the sliding speed is gradual as compared with that in air.View full abstractDownload PDF (790K) -
Toshinobu Miyamoto1978 Volume 42 Issue 1 Pages 41-47
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSReversible temperature coefficients of magnetic flux densities at various operating points on the demagnetization curves of columnar Alnico 5, columnar Alnico 8 and Fe-Cr-Co alloy magnets were measured using a nuclear magnetic resonance method. The temperature coefficient of Alnico 5 is-(2.0±0.3)×10−4/°C between −20 and 50°C, of which the absolute value has a tendency to decrease slightly with decreasing permeance. For Alnico 8 and Fe-Cr-Co alloy, however, the temperature coefficients strongly depend on their operating points, and they markedly decrease with decreasing permeance, until the sign of temperature coefficient changes from negative to positive at some operating points near the knees of their demagnetization curves. It is found that for Alnico 8 the coefficient strongly depends on the aging condition also.
The temperature effects are reasonably explained by an offset effect of the magnetization between the weakly ferromagnetic matrix and strongly ferromagnetic precipitates in the spinodal decomposed magnet alloys, which can be expected to vary with their operating points as well as with the aging condition.View full abstractDownload PDF (530K) -
Hakaru Masumoto, Masakatsu Hinai, Yûetsu Murakami1978 Volume 42 Issue 1 Pages 47-50
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSNi-Fe-Nb alloys were heated in purified H2 gas at temperatures ranging from 750 to 1150°C for 1 h. The effects of sheet thickness and heat treatment on the magnetic properties of the alloys was investigated. Increasing the heating temperature resulted in increases in initial permeability μ0 and maximum permeability μm and a decrease in coercive force Hc. In the case of thin sheet thicknesses of less than 0.05 mm, the alloys showed small values of μ0 and μm and a large value of Hc.
The effective permeability μe showed a peak as a function of magnetic field H. The peak value decreased and finally disappeared with increasing frequency. The critical frequency at which the peak value disappeared increased with decrease in sheet thickness. With increasing frequency, μe at H=0.4 A/m first decreased gradually and then sharply. The frequency range where a gradual decrease in μe occurred became much wider with decreasing sheet thickness and lowering heating temperature. In the frequency range where the sharp decrease took place, however, the decrement in μe became smaller.View full abstractDownload PDF (308K) -
Yasunori Torisaka, Junji Kihara1978 Volume 42 Issue 1 Pages 51-56
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn the production of prestressed concrete steel wires, a series of the cold drawing-patenting process are performed to improve the strength. In order to reduce cyclic process, the low carbon martensite steel wire which can be produced only by the process of hot rolling and direct quench has been investigated as strain-tempering material. When strain-tempering is performed on the low carbon martensite steel wire, stress relaxation (Re%) increases and mechanical properties such as total elongation, reduction of area, ultimate tensile strength and proof stress decrease remarkably by annealing.
In order to shorten the heating time, the authors performed on the steel wire the strain-tempering with a heating time of 1.0 s using direct electrical resistance heating and examined the effects of rapid heating on the stress relaxation and the mechanical properties.
Stress relaxation decreases without impairment of the mechanical properties up to a strain-tempering temperature of 573 K.
Re (%) after 10.8 ks is 0% at the testing temperature 301 K, 0.49% at 363 K and 1.39% at 433 K.View full abstractDownload PDF (418K) -
Osamu Nittono, Yasumasa Koyama1978 Volume 42 Issue 1 Pages 56-63
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe progress of the crystallographic transformation as well as the twinned tetragonal structure in indium rich-thallium (20∼21 at%) alloy single crystals has been studied by means of X-ray diffraction topography. Single crystals examined are prepared by both the recrystallization and Bridgman methods; the former crystals are of a higher degree of perfection than the latter crystals, although they are composed of many subgrains. X-ray topographic observations give useful information on microstructural changes and the distribution of lattice distortion, which is not expected from optical-microscopic observations. The twinned structure changes easier on cooling than on heating. There is a temperature hysteresis of 1∼5°C between the heating and cooling transformations. An anomalous enhancement of thermal diffuse scattering of X-rays is observed in the vicinity of the transformation point. The transformation from the fcc phase to the fct phase on cooling is martensitic, and single crystals transform by the migration of a single interface. The velocity of the interface depends on the cooling rate. On the other hand, on heating a metastable two-phase region is defined over a wide temperature range, and finally single crystals become fcc single phase at a high temperature. The range of the co-existence of two phases is related with the nucleation and extending growth of the fcc phase. Since no evidence for diffusion is obtained, the observed phases are necessarily metastable, and, therefore, usual representation of the two phase field in an equilibrium phase seems to be inappropriate.View full abstractDownload PDF (1961K) -
Shigeoki Saji, Susumu Ikeno, Shigenori Hori1978 Volume 42 Issue 1 Pages 63-68
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe lattice parameter of the specimens quenched from the region of a homogenious solid solution was measured for various Cu-Ti alloys containing about 0.2, 0.3, 0.6, 1.1, 1.7, 2.5 and 5.1 at%Ti. The ageing characteristics of the alloys aged at 450°C were studied by X-ray diffraction analysis, optical and electron microscope observations.
The following conclusions are obtained.
(1) The lattice parameter of the quenched specimens increases at a rate of 0.00055 nm/at%Ti with increasing Ti concentration up to 1.7 at%Ti. For more than 1.7 at%Ti, however, the increasing rate of lattice parameter becomes smaller than for less than 1.7 at%Ti.
By transmission electron microscope observation, the decomposition of the solid solution during quenching is confirmed to occur in the alloys containing more than 1.7 at%Ti. So, it seemes that such a decomposition decreases the increasing rate of the lattice parameter for the alloys of less than 1.7 at%Ti.
(2) The lattice parameter of each alloy decreases continuously to a constant value during ageing. The decrease of the lattice parameter corresponds to the decreases of the Ti concentration in the matrix of the alloys in the ageing process: solid solution—3-phase structure (model of G.P.zone)—2-phase structure.View full abstractDownload PDF (760K) -
Kouichi Maruyama, Seiichi Karashima, Masahide Ike1978 Volume 42 Issue 1 Pages 69-74
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSIn this study, plastic deformation behaviour in isoaxial zinc bicrystals having ⟨1\bar100⟩ symmetric tilt boundaries was examined by means of tensilt tests and optical microscope observation of slip lines. This type of bicrystals has been called compatible bicrystals, because the existence of grain boundaries is expected not to affect their plastic deformation behaviour.
Contrary to expectation, however, the following facts were made clear from the results of this work. (1) The difference in work-hardening rates between stages I and II was less marked as compared with that in single crystal specimen having the same orientation as the bicrystals. (2) Clustering of basal slip lines and activation of the {11\bar22} pyramidal slip system, both of which were not observed in single crystal specimen, were found to exist near the grain boundaries.
From the experimental results mentioned above, it was concluded that the difference in work-hardening behaviour between bicrystal and single crystal specimens was due to the fact that the region, which work-hardened more than the matrix, was formed near the grain boundary.View full abstractDownload PDF (562K) -
Tensile Fatigue Strength of Annealed Cu-10 wt%Al Alloy (Hypoeutectoid) at High Temperature in VacuumShigeo Matsushima1978 Volume 42 Issue 1 Pages 75-80
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSTensile and tensile fatigue tests of annealed Cu-10 wt%Al alloy (hypoeutectoid) are performed at high temperatures in vacuum. The obtained relation among maximum σ0 of the cyclic tensile stress, tensile strength σB, number N of stress cycles to cause fracture and testing temperature T is approximately given by
(This article is not displayable. Please see full text pdf.)
\ oindentwhere B=25, A*=5.68×108 Pa and B*=1.10×10−3°C−1 below about 300°C, and B=7.5, A*=3.97×109 Pa and B*=6.68×10−3°C−1 above about 300°C.
\ oindentThese experimental results coincide with expressions of the fatigue strength derived from a fracture condition ((dε⁄dn)minN1.2=1.22:(dε⁄dn)min is minimum strain rate) under the cyclic tensile stress.View full abstractDownload PDF (464K) -
Shiro Ban-ya, Nobutoshi Maruyama1978 Volume 42 Issue 1 Pages 80-87
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe activities of zinc and cadmium in liquid Zn-Cd binary alloys were determined by a modified transportation method. The activity coefficients can be calculated by a graphical integration of the following equation using the concentration ratios of the components in the vapor and metal phases:
(This article is not displayable. Please see full text pdf.)
where Ni and Xi are the mole fractions of the component i in the metal and vapor phases, respectively.
The validity of this method has been confirmed over the entire composition range at temperatures of 800 K and 900 K. The liquid Zn-Cd solutions approximately show regular solution behavior as already reported by other investigators, and the activity coefficients are expressed by the following equations:
(This article is not displayable. Please see full text pdf.)View full abstractDownload PDF (629K) -
Takeo Yokobori, Toshimitsu Yokobori1978 Volume 42 Issue 1 Pages 88-95
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe instability of dislocation emission from the crack tip under applied stress was theoretically annalysed. Combining the results with those by computer simulation of dynamics of dislocation groups emitted from the crack tip, the micro-and-macro fracture dynamics approach has been used for the problem of fatigue crack growth.
The theoretical treatment is valid in both the blunting-resharpening model and the coarse slip model either under Mode I or Mode II loading including body-centered cubic metals and face-centered cubic metals as well.
The results explains the experimental characteristics of fatigue crack growth unifiedly, such as, stress intensity factor, temperature and frequency dependence of crack growth rate.
It was also shown that the micro-and-macro fracture dynamics approach proposed can be applied to the case of elastic-plastic cracking.View full abstractDownload PDF (608K) -
Takao Endo, Kazuaki Suzuki, Kenji Yoshida1978 Volume 42 Issue 1 Pages 95-101
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSWhen ultrasonic oscillations are applied during static testing, the static flow stress decreases. The purpose of the present work is to elucidate to what extent ‘the stress superimposition effect’ can explain this phenomenon. On the basis of the stress superimposition, the decrements in static flow stress, Δτ, were calculated neglecting the mean internal stress. From the measurements of specimen temperatures and the comparison between the measured and the calculated decrements, the following conclusive remarks were drawn.
(1) The effect of the temperature rise on the decrements was negligible in the superimposed stress range investigated.
(2) The measured decrements were larger than the calculated by a factor of about 1.5. They slightly decreased with increase in strain rates and slightly increased with increasing τA at which the superimpositions of stress were conducted.
(3) The results obtained above were qualitatively explained by the change in the fraction of the mean internal stress to the flow stress.View full abstractDownload PDF (625K) -
Mitsuji Hirohashi, Eiichiro Kawai, Kensuke Mutsuzaki, Matsuo Miyagawa1978 Volume 42 Issue 1 Pages 101-106
Published: 1978
Released on J-STAGE: April 04, 2008
JOURNAL FREE ACCESSThe plastic behaviour at room temperature is investigated on the superplastic Zn-22%Al alloys with grain sizes of 0.1∼4.9 μm. The optimum grain size giving the maximum value of total elongation existed for each strain rate.
The strain rate sensitivity m have the maximum value at grain size of about 0.6∼0.8 μm, and the strain rate sensitivity disappears above 4 μm (m\fallingdotseq0). The total elongation increases with increase in m-value at the same grain size.
The maximum tensile stress is reached at 2∼5% strain, and the grain boundary sliding of mother phase α′ is observed in these strain ranges. The local elongation after the occurrence of the maximum tensile stress depends mainly on the α-β grain boundary sliding and on the deformation of the grains.
In the specimen of optimum grain size, at low strain rate, the total elongation is large because the α-β grain boundary sliding is remarkable, but at high strain rate, the specimen is brittle because the α-β grain boundary sliding does not occur and the intercrystalline cracks of α′-boundary is observed. In the large grain size alloy, the deformation of grains is observed at any strain rate.View full abstractDownload PDF (577K)
- |<
- <
- 1
- >
- >|