The purpose of this study is to clarify the wear mechanism at high speed cutting, that is, high tool face temperature where mutual diffusion at interface comes to active. The relation is investigated and discussed between the crater wear rate and the condition of diffusion layer by cutting test and dynamic diffusion test, for reference. Combination of materials is cermet tool of TiC type to plain carbon steel of 0.45% C. In the cutting test by turning, cutting speed varied from 2.5 m/s to 7.5 m/s. In the dynamic diffusion test, both samples, contacting each other with a plane inclined at 5 degrees under axial load, were kept for 30 minutes in argon gas at various temperatures from 1 273 K to 1 473 K. The surface of samples was observed and analyzed with SEM and EPMA. The main results obtained are as follows : (1) At tool face temperature over 1 300 K, wear rate depends strongly upon that temperature. (2) In that case, there is observed the Ti-rich layer on worn surface, which is hard and brittle layer of several gm thick. (3) A model is considered in which wear proceeds by repetition of formation and tearing off of the layer. (4) the layer is produced as a result of diffusion at interface and squeeze of binding material of Ni by pressure. (5) Also in the diffusion test, Ti-rith layer is observed.

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An attempt has been made to evaluate the grade from the analysis of AE signals detecting small amounts of energy release caused by the fracture of the local area of the wheel surface. Present report mainly describes; (1) the characteristics of AE wave propagation in the wheel, (2) quantitative relationship between AE counts and the amount of fracture by using the Okoshi's grade testing machine, and (3) strain rate dependence of AE, respectively. Ringdown counting is selected by taking into account of both intervals of AE events and ringing time. In order to compare each data quantitatively, sensitivity is adjusted such that the counts of artificial AE wave obtained by rupture of lead (HB) indicate same value. Specimens tested are 15 different kinds of vitrified wheels. The results are as follows : (1) As frequency of AE waves, the frequency component more than 350 kHz should decrement during wave propagation in the wheel and that AE counts are independent of natural frequency. (2) AE counts should have one to one correspondence to the amount of fracture.

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As a basic study to establish high efficient machining processes of brittle materials such as fine ceramics, the trial construction of an ultrasonic grinding machine is done and the machining characteristics of this equipment is considered with soda glass. Because of high stock removal rate in ultrasonic grinding, this method proved to be efficient for brittle materials. The stock removal rate becomes higher in accordance with the increase of loading weight, amplitude of ultrasonic, wheel speed and so on.

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The feed per tooth f_z for slab-milling was varied to observe effects of the density d_z (=1/f_z) of cutting edges acting on machined surface in unit length. As the d_z is increased, macroscopic residual stresses σ_xv and σ_yv translate into a compressive stress and microscopic residual shear stress τ_zxw decreases. Decreasing d_z results in growing fiber texture in a machined layer and the principal slip planes α·Fe {110} in medium carbon steel concentrate along a direction inclined to the machined surface. The microscopic τ_zxw is generated by the slip on the planes. The effects of d_z, on τ_zxw for up-milling are stronger than for down-milling. The effects of d_z appears also in a carbide phase in high speed steel.

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In order to get a foundation for scientific understanding of high precision and high productivity grinding of fine ceramics with metal bond diamond wheel, cylindrical plunge grinding processes of normally sintered silicon nitride, alumina, partially stabilized zirconia and reaction bonded silicon nitride are experimentally analyzed with bronze bond diamond wheels. Main results obtained in this paper are as follows : (1) There are three distinct grinding states in a plunge grinding cycle of normally sintered fine ceramics just as in grinding steels. (2) The ratio of tangential force to normal one is remarkably smaller in grinding fine ceramics than that in grinding steels. (3) The wheel wear in grinding reaction bonded silicon nitride is larger than that in other normally sintered fine ceramics. (4) Grinding ratio becomes lower in the order of partially stabilized zirconia, alumina, silicon nitride, and that of reaction bonded silicon nitride is the smallest of all work materials used in this study.

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Since flow stress characteristic of material is the key factor in the analysis of cutting performance, an impact compression test of difficult-to-machine materials was conducted at high temperature and strain rate, which are usually observed in the shear zone of machining. History effects of strain rate and temperature upon flow stress were also investigated. As the result, constitutive equations of titanium alloy, stainless steel and nickel base superalloy are obtained in terms of strain rate, temperature and their history effects. It is found that these materials have very high flow stress and that the history effects are similar to those of α-brass reported previously. Yield stress and strain hardening of titanium alloy are high, but its fracture strain is small. Flow stress of stainless steel varies considerably with straining conditions, especially temperature, while little does so that of nickel base superalloy. A qualitative evaluation of tendency toward adiabatic deformation in terms of Pklet number and flow stress characteristic reveals that titanium alloy is more likely, to produce saw-toothed chips than others, and nickel base superalloy and stainless steel are ranked next in due order.

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The purpose of this study is to develop a very useful grinding tool for finishing automatically the free-form metal surface of a mold cavity on the NC milling machine. A dual-axis microgrinding tool has been developed, in which a small disk grinding wheel having a part of the spherical body (diameter; 25 mm) can revolve on both the wheel and the spindle axes at the same time. This dual-axis micro-grinding tool has the following properties : (1) The tool can finish the free-form metal surface at high grinding speed and also at the almost same speed at every grinding point, namely the grinding speed is 1 130-1 140 m/min and only 0.7% of that is changed in all over the range of 0-90° inclination angle of mold cavity surface. (2) The small disk grinding wheel is rotated reversely every half revolution, so that the cross loci of abrasive grains are produced automatically on the surface. This reversal grinding motion has something in common with human operation for obtaining a mirror surface by hand work. (3) In grinding operation with CBN 120 metal bond wheel, the tool can finish a spherical cavity surface to a smooth surface of less than 2.5 μmRz.

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Fabrication technologies for micro-sockets used in the packaging of Josephson chips are reported. Packaging technologies for Josephson chips are required to satisfy the conditions of high package density, and usability at low temperature and heat cycles. For this purpose, specially designed micro-sockets fabricated on Si substrate with tapered cavities containing mercury drops are studied. Photolithographic and anisotropic etching techniques using a KOH solution are applied to form the tapered socket cavities in the substrate. These techniques make possible batch fabrication as well as obtaining of precise socket pitch and aperture width. In order to fill the socket cavities with very small mercury drops, an automatic injection apparatus is developed, which takes advantage of mercury's good stickness with SiO₂ surface. Precisely uniform mercury drops can be injected by transferring the pressed and appeared mercury drop on the glass tube top into the substrate cavities. Fabrication technologies for the micro-sockets used in high package density (pitch 300 μm) with precise mercury drop size (diameter 210± 10 μm) can be realized.

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A method in order to calculate the positions of feature points on a polyhedral object is presented. The method uses a single picture of both an object and its mirror images in a mirror or mirrors set in a field of vision. The unknown 3D coordinates of feature points on an object can be calculated by solving the simultaneous equations which are derived from the 2D coordinates of a pair of projected picture points corresponding to an object point and its mirror image point. The hidden surfaces of an object being imaged in the mirror, the positions of feature points on the hidden surface can be obtained. The results of fundamental experiments are shown.

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This paper presents the result of comparison of hardness, where the accurate Rockwell and Rockwell superficial hardness testing machines, their quarter load hardness testing machines (1st report) and the standardized hardness blocks of five levels are applied. The first comparison is made between the first two machines and the sub-standard hardness testing machine (National Research Laboratory of Metrology type) to confirm total accuracy of the former ones, the differences are -0.4-0 in HRB and -0.3-0 in HR 30 T. In the second comparison between HRB·FIR 30 T and their quarter load hardness HRBQ·HR 30 TQ, the differences are -0.2-0 (HRB 100-50), -0.9 (HRB 30) between HRBQ and HRB, and -0.1-0.2 (HR 30 T 80-32) betwen HR 30 TQ and HR 30 T. These values are small enough to verify the utility of HRBQ and HR 30 TQ. Moreover, the utility of the other quarter load hardness scales is presumed. The errors of geometric similarity of indentations, that is, the differences between d_2Q : d₂ (the ratios of diameters of HRBQ·HR 30 TQ indentations to those of HRB·HR 30 T indentations, respectively) and 1 : 2 (the ratio of the sizes of the respective indenters) are lower than 1%. The errors of similarity in hardness, that is, the differences between h_bQ : hb (the ratios of the depths of indentations which are calculated with respective hardness numbers) and 1 : 2 are lower than 1%.

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This paper describes some experiments with the wear of copper cylindrical bearing which is guided linearly by steel shaft under lubricated reciprocating sliding. The obtained results are as follows : (1) The wear curve of the bearing is linear under most of sliding conditions, but, under the condition of a small stroke or of a low load, it shows that the wear rate of the bearing decreases as the sliding distance becomes greater. (2) The wear rate of the bearing decreases as the sliding velocity or the lubricant viscosity becomes greater, also as the beginning roughness of the shaft becomes smaller. The wear of the bearing increases little under the load lower than the critical load, and the critical load increases as the sliding velocity or the lubricant viscosity becomes greater. (3) The wear of the bearing at a fixed sliding distance decreases as the stroke becomes smoller than the bearing length. (4) The above phenomena are explained by the change of the shaft roughness, the hydrodynamic effect of the lubricating oil and the geometrical relationship of the contacts.

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Grinding wheel wear equation for optimization of grinding process has been given in the form of the equation representing the relationship between grinding ratio and feed rate. However the other factors (work material, wheel, wheel speed, etc.) which affect to the wheel wear, seem not to be taken into consideration. In this paper, the wheel wear equation in abrasive cut-off operation is presented, in which chemical compositions and mechanical properties in work materials, abrasive grain, grain size, grade and wheel speed are treated as independent variables together with the feed rate, using input and output data given by the experiments and GMDH (Group Method of Data Handling) algorithm with successive determination of polynomial trends. As the results, the wheel wear equation can be obtained, of which construction is rather simple and accuracy is satisfactory.

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The planetary screw has advantages over ball screw, because its pitch becomes smaller and larger rated load can work on the screw. In this study, its peculiar structure and moving principle are described and measured apparent coefficient of friction is clarified in comparison with ball screw and trapezoidal screw. As a result of experiment, the apparent coefficient of friction is 0.015, which is between those of ball screw and trapezoidal screw, and its consideration is made in view of retainer friction and spinning force of rolling elements.

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A method is discussed in which the wear process in the leadscrew-nut system is simulated using a couple of cylindrical models proposed. To simplify the contact condition geometrically between screw and nut with trapezoidal thread profile, a couple of cylindrical models touching each other in the end surfaces is applied. The wear of the practical leadscrew is simulated by observing the wear depth at the end surface of the cylindrical model corresponding to the wear depth at the flank of thread. In order to evaluate the propriety of the cylindrical model, the wear tests of the practical leadscrews and the simulation tests with the cylindrical models are performed. In the simulation tests, the testing conditions, such as the materials of specimens, the type of lubricant, the contact area ratio, the contact pressure and the sliding speed, are similar to those in the practical tests. It is considered on the basis of the experimental results that the lubricating condition and the wear character along the frictional surfaces of the simulator are corresponding to those of the practical system, and a prospect is obtained that the simulation for the leadscrew wear is possible by the cylindrical model within the limits of the condition set in this study.

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