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Volume 38, Issue 451
Displaying 1-11 of 11 articles from this issue
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[in Japanese]1972 Volume 38 Issue 451 Pages 623-630
Published: August 05, 1972
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSDownload PDF (1393K) -
Changes of Metal Surface Properties Induced by Plastic Deformation (1st Report)Yoshio TANAKA, Mamoru IDO1972 Volume 38 Issue 451 Pages 631-637
Published: August 05, 1972
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn this paper, it is proposed how to calculate the metal surface property values during ultrasonic hammering, which has a lot of merits as the method of giving the plastic deformation of the metal surface, by the depth for the indentation and others in this working. Then the behaviours of the deformation of the metal surface during the hammering is examined.
The main results are as follows:
1. The surface stiffness and the rate of the elastic recovery can be calculated by the two arbitrary values from among those of the depth of the indentation, the contact time and the stationary load produced by the hammering on the metal surface with the vibrating tool.
2. The applicability of this calculating method is confirmed by the comparison between the calculated values of the depth of the indentation and the experimental results.
3. The depth of the indentation is affected by the repetition of the hammering on the same region of the surface. In the case of copper, the amount of the depth of the indentation increases a little by this repetition but in the case of S 15 C steel, hardly increases.
4. In the case of the low movement speed of hammering point, the nominal surface stiffness and the rate of the elastic recovery during working correspond with those given by the static and repeated indenting test.View full abstractDownload PDF (1281K) -
Cam Profile, Outer-Diameter Restriction and Undercut RestrictionHiroshi MAKINO1972 Volume 38 Issue 451 Pages 638-644
Published: August 05, 1972
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThough the parallel index cam is a two-dimensional cam and easy to manufacture as compared with the other three-dimensional index cams, designing the cam is rather difficult because there are some restrictions on deciding the value of cam specifications such as the index angle θh and the follower size ratio l/c. This report deals with two kinds of restriction: outer-diameter restriction and undercut restriction. The limit values by the restrictions are calculated for some cam curves and shown in charts.View full abstractDownload PDF (942K) -
Study of Grinding Surface Roughness (3rd Report)Yoshihiro KITA, Mamoru IDO1972 Volume 38 Issue 451 Pages 645-651
Published: August 05, 1972
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn the former report; it was insisted that the behavior and interfered phenomenon of swell out residual were largely influenced by the shape facter L/D (L; the diameter of the bottom of frustum, D; the depth of cut) with cutting edge of frustum of a cone.
So, in this report, in order to relate the shape factor to the cutting force and clarify the action of cutting edge more detail, the cutting force is analyzed by dividing the force into two parts, which are the force acting to the inclined face of cone and the force acting to the flattened plane of the bottom.
Then we discussing the results of experiment and the analysis, the following were clarified.
1. The cutting force with the edge of frustum of a cone can be explained well by the analysis dividing the force into inclined face and the bottom.
2. The specific cutting force aσn which is perpendicular to the cutting direction and at which is tangential to the cutting direction depends on the shape factor L/D. As the shape factor increase σt increases lineally, but σn decreases exponentially, and these must have a closed relation with the behavior of swell out residuals.
And in the case of interference, the cutting force is plopotional to the projective cutting area but if the distance between two grooves is small, the influence of work hardening of materials becomes signifcant.View full abstractDownload PDF (1157K) -
Influence of Pre-strainToshinori KORI, Toyomitsu SENDA, Takayuki IKEDA, Masaaki ISHIYAMA, Tak ...1972 Volume 38 Issue 451 Pages 652-658
Published: August 05, 1972
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThe propagation of longitudinal plastic waves, produced by the rotary disc impact testing machine, is observed by plastic strain gages attached to the aluminum and copper ribbons. And the influence of pre-strain on the propagation is studied. The main results obtained are as follows.
1) The experimental velocity of longitudinal plastic wave propagation in aluminum and copper ribbons not pre-strained exactly coincides with the velocity calculated from the Karman's theory. But in pre-strain ribbons the experimental velocity is larger than the calculation velocity.
2) The elastic front is not observed in the materials not pre-strained, but is observed in the materials pre-strained. The plastic front is not observed in any material.
3) The plastic strain wave attenuates through the propagation. With the increase of pre-strain, the attenuation increases.View full abstractDownload PDF (3808K) -
Studies on Powder Particle Beam Machining by Electrostatic Acceleration (1st Report)Hideo TSUWA, Yuzo AKETA, Takashi IDE1972 Volume 38 Issue 451 Pages 659-666
Published: August 05, 1972
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSIn order to develop a new method of "powder particle beam machining", an approach to obtain highly charged powder particles has been made by contacting powder particles with electrode maintained at a high potential, or by "contact charging".
The charging mechanism is theoretically analyzed by the image method for the contact model of two spheres, and it follows that the relation between the surface electric fields on both spheres is expressed as the function of the ratio of sphere radii. The theory is experimentally justified by a model experiment using the steel spheres of several millimeters in size.Further, it is experimentally proved that the extended contact charging theory is applicable to the charging mechanism by field emission.
The charging of fine powder particles is made with the two types of charging electrode and the amount of charge is measured with a Faraday cage. The maximum amount of charge on tungsten powder of 0.5 μm in diameter becomes 1.6 × 103 times of electronic charge and its surface electric field strength reaches 2 × 107 V/m. This result may signify that the kinetic energy of powder particle attains to 1.6 × 103 times of an electron accelerated under the same potential difference and the velocity of the powder particle may reach to 200 m/s at the accelerating voltage of 100 kV. This suggests the possibility of "powder particle beam machining".View full abstractDownload PDF (1458K) -
Katsuzo OKADA, Teruzo SHIMIZU, Noboru TAKAHASHI1972 Volume 38 Issue 451 Pages 667-671
Published: August 05, 1972
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThin foils of deformed superficial layers in 18-8 stainless steel produced by ultrasonic machining were prepared by electropolishing and their structure was examined by transmission electron microscopy. The main results obtained are as follows:
1) Deformed superficial layers changed their structure from the surface to the interior successively; fracture, crystallites, plastic deformation, elastic deformation, matrix.
2) In crystallites, dislocations were densely tangled and α-phase martensite was formed by transformation due to high-temperature plastic deformation. Though cracks found in crystallites had no preferred orientation, sometimes microcracks along the planes {111} were observed in a plastically deformed region.
3) Some lattice defects, such as pile-ups and tangle of dislocations, stacking faults, stacking fault tetrahedra, were observed in a plastically deformed region. ε-phase martensite was also recognized.View full abstractDownload PDF (13675K) -
Eiji USUI, Takahiro SHIRAKASHI, Koji TAKADA1972 Volume 38 Issue 451 Pages 672-678
Published: August 05, 1972
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSSlip line solutions which gives the coefficient of tool-face friction more than unity are proposed and compared with machining experiments of pure aluminium. The solutions appear to be in success for the explaining chip formation and cutting forces. Slip line solutions for machining with tools of double rake angles are proposed and discussed with the solutions for cut-away tools.
A slip line solution in the vicinity of cutting edge roundness is proposed. The plastic flow and the stress distributions on the roundness obtained from the solution are verified to be in good agreement with the results of machining experiments although the experiments are in particular conditions.
Plastic flow layers remaind on the finished surface are discussed in conjunction with several slip line solutions which include the cases for tools with sharp, rounded and chipped cutting edges.View full abstractDownload PDF (3709K) -
Tomokazu ARAI, Motohide IIO1972 Volume 38 Issue 451 Pages 679-683
Published: August 05, 1972
Released on J-STAGE: February 16, 2010
JOURNAL FREE ACCESSThis paper describes an easy method and an instrument developed for a digital measurement of small gap length. The instrument consists of the optical system with a photo-electric transducer and the electronic circuit.
In the measuring system, small gap length is detected as transverse time of light spot on the gap, and the time is measured by counting the corresponding number of pulses from the reference clock oscillator.
It is examined experimentaly that the relations between count error and frequency of the reference clock oscillator, the error due to misalignment of gap elements.
From the result of the experiment, it is said that this non-contact method enables the measurement of small gap length without any fixed datum, and that the measuring range of small gap length by the instrument is from about 01.2 mm, with error of 0.3%.View full abstractDownload PDF (6168K) -
The Effect of Machined Surface Layer and Inclusion on Fatigue Strength (2nd Repot)Kozo KISHI, Hiroshi EDA1972 Volume 38 Issue 451 Pages 684-690
Published: August 05, 1972
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSThis paper is a report a fatigue test for bending during revolution of High-carbon Pb free-cutting steel executed to define a distribution of residual stress on the cutting layer and a meaning for existence of a distribution of hardness in connection with fatigue strength. Furthermore, it mainly applied an examination onto the disappearing processes of residual stress and hardness distribution and also onto crack development due to an existence on the working layer and a variation of a fracture, hence the following results have been obtained.
(1) A distribution of axial compression residual stress on the cutting layer in case of stress vibration being 25-45 kg/mm2 has been disappeared within the range of repetition N= 0-103 and no further distribution in the subsequent repetition could be recognized.
(2) A distribution of hardness on the cutting layer within the range of stress vibration being 25-45 kg/mm2 caused independently from the disappearing processes in a distribution of residual stress and as it drew near to the fatigue limitation 28.8 kg/mm2, the distribution has come to exist up to the proximity of approx. N=105 times.
(3) A crack on the cutting layer resembled the propagation of a crack seen in the brittle material, which proceeded straight on towards an axis of a test-piece. Further, it provided no choice for a crack propagation route so much as seen in Pb inclusion of the matrix, even if there might exist Pb inclusion between the layer.
(4) A tire track could be recognized on an even surface on a fracture of the cutting layer, and also many rub marks could be coexisting with it.View full abstractDownload PDF (12810K) -
[in Japanese], [in Japanese], [in Japanese]1972 Volume 38 Issue 451 Pages 691-701
Published: August 05, 1972
Released on J-STAGE: June 30, 2009
JOURNAL FREE ACCESSDownload PDF (18628K)
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