An attempt is undergoing to apply carbon fiber reinforcement carbon composites, C/Cs, to a heat exchanger to an engine system for a future space plane. One of main difficulty in this application is leakage of working fluid, hydrogen, which easily run through cracks and pores in the material. To consider measure to minimize the leakage, gas leak rates were measured as a function of pressure. Then, to clarify ruling mechanisms of the leakage, simple models were examined. It was found that the gas leak rate was found to be simulated by the equation used in the field of labyrinth seals.

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Coatings on the surface of C/C composites have been studied for use as oxidation protection systems. It is well known that the mismatch in the thermal expansion coefficients (CTEs) between a C/C substrate and ceramic coating causes a large number of coating cracks. In this study, the Si-Impregnated SiC coating reinforced by carbon fibers was examined. The beneficial effect of the fiber-reinforced SiC coating is mainly to reduce the number of the cracks owing to the reduction in the CTE mismatch and the thermal stress in the coating.

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Creep test was carried out on solid solution aluminum alloys to study the effect of solute atoms on deformation behavior and creep property at high temperatures. Two kinds of aluminum alloys, A5083 and A6061 were tested. We obtained the experiment equation, t_f = λσ^<-m> for the relation between the applied stress and creep life. The exponent, m was constant independent of the temperature. For A6061 alloy, the contraction creep was observed at lower applied stress. The behavior was expected to be due to the interaction of solute atoms, Mg and Si.

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Refractory and corrosion resistant diaphragm type transmitter was fabricated for HI cycling pressure sensor of IS hydrogen production process and tested its high cycle fatigue properties. Ta/SUS316 was jointed by ark welding technique and this joint was applied to the diaphragm part of this transmitter. After fatigue test, it is concluded that this pressure sensor still survive over 5,000,000 cycle within 0.44%F.S./K error and fatigue test has been continued over 5,000,000 cycles.

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Simultaneous sintering and bonding of pure aluminum powder and mild steel (SS400) bar were carried out by the pulsed electric-current sintering (PECS) process. Relative density of sintered aluminum was about 99.3 to 100%. An intermetallic compound layer (FeAl_3) was formed at the bonded interface in Al/SS400. Thickness of the layer increased with an increase in bonding temperature and holding time. The tensile strength of the bonded joint was about 70MPa at 773 and 823K under 98MPa pressure.

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At the joint of the ordinary piping of the carbon steel using the conventional welding methods or the mechanical joining, the formation of step is hard to avoid, which causes the stress concentration. We proposed the new welding method of the braze-pressure-welding (B.P.W) by the electromagnetic induction heating. The process uses the brazing filler material inserted at the joint interface, which is expected to fill the step to form fillet. It is considered to relief the stress concentration. In this research, the validity of the fillet is evaluated by the stress analysis using the finite element method. The carbon steel pipes are welded by this B.P.W. method in the air. The method to avoid the hard oxidation of the pipe is also proposed. At the joint, the oxidation is slightly occurred and the fillet is formed. The EDS analysis of the distribution of the atomic contents shows the brazing filler is ejected out of the joint interface. The tensile test yields the joint has the comparable strength with the bulk material.

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Palladium-containing braze alloys were selected because of their ductility, oxidation resistance, relatively high melting points. Newly developed palladium-containing alloys, Pd-Ni-Co, were considered for use in brazing Inconel 600 for high temperature applications: 40Pd-50Ni-10Co, 30Pd-50Ni-10Co-10Cu, 40Pd-49Ni-10Co-1B, and 40Pd-47Ni-10Co-3B. The joints brazed with 40Pd-50Ni-10Co had tensile strengths of 130 to 561 MPa from 20° to 800℃. The 40Pd-50Ni-10Co joints can sustain tensile stress levels at or 150 MPa without fracture after more than 10^7 cycles at 600℃.

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Powder particles of polystyrene coated with nickel-phosphorus alloy layers using electroless plating were pressed into pellets by isostatic pressing and sintered in vacuum at high temperature. A metallic closed cellular material was then fabricated. The compressive tests of this metallic closed cellular material containing organic materials were performed. The obtained results show that this material has the different stress-strain curves among the specimens that have different thickness of the cell walls. Also these results show this closed cellular material has a long plateau region in the curves and high energy absorption. The cracks occur in the direction parallel to the loading axis in the plateau region and the broken cell walls were observed on the fracture surface. It should be thought that the fracture of cell walls causes this high energy absorption.

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Many types of materials developed are summarized as actuator materials. Martensite transformation, glass transition, superconductive transformation, magnetostriction, polarization, twin formation and thermal expansion induce movement. In order to apply practical articles, load dependence is important factor. Thus, we were examined load dependence measurement each shape memory materials, which developed. As a result, large power has been found in hydrogen storage alloy bi-materials.

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Combining the multi-functional sensor/actuator devices with telecommunication module will undoubtedly extend more wide application fields of intelligent/smart materials and structures. Our recent developments of new functional solid state senor/actuator, SMA and magnetostrictive alloy materials by controlling crystalline micro structure by rapid-solidification technique are introduced. Next, smart composite system with active and embedded nondestructive evaluation module etc. are introduced. Wireless sensing and active sensing combined with IT(information technology) seem promising and valuable subject in the very near future for smarter design concept.

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In this research, the composite material with shape memory function is used as model material of photoelastic experiment. Photoelastic experimental hybrid method is developed in this research, it is assured that it is useful on the obtaining stress intensity factor and the separation of stress components from only isochromatic data. The measuring method of stress intensity factor of intelligent material by photoelastic experiment is introduced. As the result, the fracture resistance of the matrix (base material) as well as the TiNi fiber improved. This is due to decreasing stress intensity factor K_I caused by raising the ambient temperature in the iso-temperature furnace.

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This paper describes development of an active and sensitive composite based on a simple metal composite. To realize this material system, continuous titanium fiber was embedded in aluminum matrix together with stainless steel reinforcement fiber, of which surface was oxidized to be insulated from matrix to form a heater and a temperature/strain sensor. It successfully actuated and sensed temperature and electric resistance changes with the multi-functions of the embedded TiO_2/Ti fiber.

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Since ferromagnetic shape memory alloy (FSMA) was discovered, the various researches has been done for the industrial application as sensor and actuator materials. However, the detailed mechanism of the magnetostriction, which appears in polycrystal FSMA, has not been clarified still. In this study, Fe-29.6at%Pd and Fe-23.0at%Pt alloy of the ferrous material with the ductility were made to be the polycrystal ribbon by the rapid solidification apparatus. The investigation of giant magnetostriction, which appeared in the polycrystal FSMA ribbon, was made to be a purpose. As results: 1) The magnetostriction of rapidly solidified ribbon is bigger over 10 times than the bulk. 2) The coercive force of the ribbon has strong directional dependency. 3) From magnetostriction measurement, austenite phase transformation occurred in the 400K vicinity. While in magnetic properties and X-ray diffraction, austenite phase transformation occurred in the 300K vicinity. In addition, shape recovery test indicated 2-steps transformation.

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A variable reluctance hybrid magnet have been developed to apply new type of high torque motors. The variable reluctance hybrid magnet is constructed by a permanent magnet, electromagnet and yoke. The variable reluctance hybrid magnet is higher efficiency than that of normal motors.

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Aluminum squeeze castings have been used as automobile or other machine parts. Because their defects were lower than the conventional die castings. Effect of hydrogen and inclusions in cast AC4CH alloy on the reliability of mechanical properties were investigated. After controlling the hydrogen content or the inclusion size, the molten alloy was cast into a cavity with 90 MPa. The hydrogen content increased by the addition of potetos into the molten alloy. The inclusion size was controlled by a stainless steel mesh, which was set at the gate in the cavity. In the as-cast material, the fracture elongation increased with the addition of hydrogen. Because the bubbles, which broke out when potatos added into the molten alloy, removed the inclusions from the molten alloy. The fracture elongation increased with a decrease in the inclusion size. But the reliability of fracture elongation, the shape parameter 'm' of Weibull distribusion, was hardly affected by the inclusion size.

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In this study, bending properties of honeycomb sandwich curved panels had been investigated with three-point bending experiment and 3D-FEM. As a result, it was found that the maximum bending load was not influenced by radius of curvature and thickness of the specimen, because it was subjected to the volume density of core. Moreover, it was made clear that the bending rigidity was strongly influenced by thickness of the specimen and the highest value of bending rigidity was indicated in the radius of curvature from 300mm to 400mm.

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In order to study the impact properties of the honeycomb sandwich panel (hereafter, HSP for brevity), current drop weight impact tests were carried out using 4 kinds of panels at several drop heights. Where, cores were used an aramid and its core heights were 22.5mm and 6.3mm. Surface boards of HSP were used the aluminum alloy (A1100P) and the fiber reinforced plastic (hereafter, FRP for brevity). Based on observed deceleration waves of the weight after the impact between the weight and the flat plate, absorption energies were calculated. When the energy absorption abilities were compared, HSP with flat plates of the aluminum alloy was superior to that with FRP. This was attributed to the fracture forms at impact applied point.

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More than 90% of failures of machines and mechanical parts are caused by fatigue. In addition, approximately 90% of the fatigue cracks initiate at a stress concentration part of structural component. Therefore, it is important to improve the fatigue limit of a notched specimen. In this study, the fatigue properties of specimens with circumferential notch have been investigated using Ono-type rotating bending fatigue test machine. The main results obtained in this study are as follows: (1) The fatigue strength of a notched-specimen considerably increases by roller-working. (2) The improvement of fatigue limit by roller-working would be attributed to work-hardening and compressive residual stress. (3) Furthermore, the non-propagating cracks are observed in the specimen subjected to the stress amplitude of fatigue limit by 1 × 10^7 cycles.

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Carbon steels are used in many fields of industries because of their good properties and low cost. These materials are generally utilized as the structural steels after receiving the plastic deformation such as tension or bending. Therefore, it is important to evaluate the effect of pre-strain on the fatigue strength of structural steels. In this study, the fatigue tests have been performed to investigate the fatigue strength of pre-strained structural carbon steel using Ono-type rotary bending fatigue testing machine. The main results obtained in this study are as follows; (1)The fatigue strength of small pre-strained specimen is lower than that of non-pre-strained one. (2)The fatigue strengths of pre-strained specimens increase with increase of pre-strain value. (3)The fatigue strengths of pre-strained specimens increase after annealing.

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The possibility that pipes made by magnesium alloy are applied to bicycle frame is investigated. At first by the tensile test the fracture toughness test and the fatigue crack propagation test ,several mechanical characteristics are obtained. Next the actual bicycle frame which is constituted of magnesium alloy pipes at aluminium alloy lugs is actually made. The deformation of the frame is examined using digital video scope. Maximum displacement is compared with FEM computer simulation.

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Recently, the application of magnesium alloys has been expanded to various industries due to its light weight and recyclability. Most magnesium alloy products are now produced by casting, but plastic forming processes have a large advantage from view point of environmental preservation, quality and productivity. This research focuses on producing and evaluating bar and rod rolling by using casted and extruded AZ31 magnesium alloy.

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The strength and absorbed energy on CFRP-aluminum alloy hybrid bonded material were investigated under impact load. The effect of impact velocity was examined experimentally. In experiment, impact three point bending tests using Charpy impact tester were carried out. Two-ply CFRP was bonded adhesively the side, which was subjected to tensile load, of aluminum alloy. The impact velocity was changed as 1.5, 2.5, 3.5 m/s. The effect of the impact velocity was estimated concerning the strength and absorbed energy. The effect of the impact velocity was not remarkable on the aluminum alloy without CFRP. But, when the head speed was increased, the absorbed energy of CFRP-aluminum alloy hybrid specimen increased.

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Al thin films were deposited on Si substrates by an ECR ion-shower sputtering system. In order to clarify the effects of fatigue on various properties of Al sputtered thin films, a fatigue test equipment composed of piezoelectric actuators was developed. The fatigue test equipment has about 100μm stroke and 200N maximum load. X-ray diffraction method, nano-indentation and electric resistance were applied to fatigue specimens. Change of the X-ray diffraction profiles were observed on the fatigue damaged specimens.

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Elastic property determinations of several kinds of electroless Ni-P coatings deposited on a steel substrate have been performed. First, Young's moduli of NiP composite coatings are determined using a surface acoustic wave spectroscopy and the ultrasonically determined ones are compared with both mechanically determined ones using a nanoindentation and theoretically estimated ones. The results have clearly shown that SiC particles dispersion causes an increase in Young's modulus of composite coatings and conversely, Teflon particles dispersion decreases Young's modulus. Next, Young's moduli for several NiP coatings heat-treated at various temperature are examined. The result has shown that Young's modulus of NiP coating increases up to about 33% as tempering temperature increases and it has a maximum value by heat-treating at 773K.

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Thin hardened layer inevitably exist on the polished mechanically treated measured by an ultra-micro hardness tester. In the report the effect of the hardened layer to micro hardness is examined theoretically by FEM computer simulation and experimentally by hardness test using large-sale specimen. The main result is that penetration depth is inevitably needed at least over thickness of hardened layer for pure balk hardness.

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FEM computer simulation of the process which an indenter penetrates thin film during hardness test using ultramicro hardness tester is carry out to find out the ideal condition and effect of contact condition of interface between film and substrate. The main results are as follows, (l) Accurate ultramicrohardness of thin film is necessary to limit the plastic inside a thin film. (2) Weak contact of interface makes hardness lower. (3) The hardness test using the large-scale model is almost the same in FEM computer simulation.

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In order to obtain sound welded joints in the welding of horizontal fixed pipes, it is important to control the back bead width in the first pass. However, it is difficult to obtain optimum back bead width, because the proper welding conditions change with welding position. Besides, because welding heat accumulates in the joint area of the pipe, the temperature rises with the progress of the time. Now, in this paper, a new method is developed to sensing of weld pool condition and control of penetration in fixed pipe welding from reverse side. As it is difficult to measure the back bead width directly, it is estimated by analyzing the shape and the dimensions of the molten pool images. Artificial Neural Network is used to estimate the relations among the parameters of the weld pool shape, welding conditions and the penetration of weld. The back bead width is controlled by optimizing the welding current estimated from the output of the Artificial Neural Network. As a result of welding control experiments, the effectiveness of this system for the penetration control of fixed pipes is demonstrated.

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A prototype of autonomous mobile robot with two vision sensors for automatic welding of steel plates was constructed. The robot can move straight, steer and turn around the robot center by controlling the driving speed of the two wheels respectively. At the tip of the movable arm, two CCD cameras are fixed. One camera observes the welding line near the welding torch and another observes relatively wide area in front of the welding part. The robot can be controlled the traveling speed. In the case of straight welding line, the speed of the robot is accelerated and the welding efficiency is improved. However, if the robot finds a corner of welding line, the speed is decelerated in order to realize the precise seam tracking. Therefore, the robot can realize precise and high speed seam-tracking by controlling the travel speed. The effectiveness of the control system is confirmed by welding experiments.

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Arc discharge phenomena and erosion mechanism of electrode were fundamentally studied to improve automatic Gas Tungsten Arc Welding system. The arc sometimes strike on wrong part of weld metal. This is caused by erosion of the electrode and turbulence of electro-magnetic force during arc welding. Arc phenomena on arc ignition stage were captured by ultra high speed video system to analyze sputtering and erosion mechanism in various combination of electrodes and shielding gas. Plasma and electrode surface temperature distributions were measured simultaneously. Some experiments were carried out in vacuum chamber to discuss anode and cathode behaviors.

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Authors have been accumulating many experimental data of underwater welding process for offshore construction, maintenance and repair. Arc welding is the most basic technology in industry, however, physical analysis of arc welding process is still an outstanding issue. We analyze motion pictures of arc phenomena to understand actual arc welding process. Recent advancement of Information Technology makes it possible to provide this dynamic information of arc welding process as a multimedia database. We describe summary of the welding process information database in XML and the technique to reduce data size.

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In this paper, a diagnosis method for machine faults using a neural network based on autocorrelation coefficients of wavelet transformed signals is presented. It is important for factory engineers to accurately estimate machine faults. In conventional diagnosis methods, frequency analysis using the fast Fourier transform (FFT) has often been employed. Recently, wavelet transforms have been studied and applied to many signal-processing applications. Wavelet transforms are very useful because of characteristics of time-frequency analysis. In this paper, we propose an application of wavelet transforms to machine fault diagnosis. In order to apply wavelet transforms to machine fault diagnosis, we use autocorrelation coefficients of the wavelet transformed signal. In this research, it becomes clear that the autocorrelation coefficients, represent the different classes of machine states. For the automatic diagnosis, we trained a neural network to recognize three classes of machine states based on the autocorrelation coefficients of wavelet transformed signals. Simulation and experimental results show that the trained neural network could successfully estimate machine faults.

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It has been reported that metals with ultrafine grains(UFG) show outstanding properties such as high strength and toughness at ambient temperature and high corrosion resistance. Intense plastic deformation is considered to be the most appropriate process for grain refinement. We have proposed a novel rolling process, i.e. accumulative roll-bonding (ARB) process, which is capable of producing intensive plastic deformation in a sheet material without any dimensional changes. Ultrafine grained ferrous and aluminum alloy sheets, of which mean grain size is less than 1μm and with very high strength have been successfully fabricated by this process. In this study, the ARB process has been applied to oxigen free copper, whose stacking fault energy is lower than ferrous alloys and aluminum alloys. At lower strain (less than 4), dislocation cell structure develops in the specimens. At higher strain (lager than 4), ultra-fine recrystallized grains appear, whose grain size is about 1 μm. After 7 cycles, lager recrystallized grains with grain size of about 5 μm appear. Tensile strength increased from 215MPa to 425MPa by 11 cycles of ARB. Total elongation decreased from 55% to 10% after 1 cycle, but it tended to increase slightly with increasing equivalent strain.

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Large shear deformation was successfully introduced throughout the thickness of 5052 and 3004 aluminum alloy sheets by single-roll drive warm rolling under high friction condition. The shear texture of which main components were {111}<110>, {112}<110> and {001}<110> prevailed throughout the thickness, and typical rolling texture was not observed at any part of thickness. Shear strain was smaller and intensity of shear texture was weaker in 3004 sheet After recrystallization, shear texture became broad and almost random texture prevailed, though weak shear texture components remained. The average r-value of annealed 5052 sheet was about 1.0 which is higher than that of the sheet fabricated by conventional rolling and annealing. The planar anisotropy was also smaller than that by conventional process. The r-value of 3004 sheets also increased by single-roll drive rolling, although the rise in r-value was smaller than 5052 sheets. The single-roll drive rolling is proved to be promising process for fabricating aluminum alloy sheet having excellent formability.

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The ECAE process was successfully used as an intense straining process to obtain ultra-fine grained metals. However, it has a problem in applicability to long, thin coiled strips. The authors recently proposed a novel continuous shear deformation process called conshearing to solve this problem. Long and thin strip is continuously fed by rolls and passes the ECA die. This process can be used to control texture. Ti-added ultra low carbon interstitial-free (IF) steel strips are subjected to the conshearing process using 55 degree die. The process was repeated up to four passes at room temperature. The shear texture with {110}<001> and {112}<111> components is evolved. The tensile strength increases from 280MPa to 450MPa.

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Semisolid strip casting of AC4C aluminum alloy for casting was tried using a melt drag twin roll caster equipped with a cooling slope. Semisolid slurry was made from melt only pouring the melt on the cooling slope. The melt drag twin roll caster was improved into a semisolid twin roll caster only equipping the cooling slope without modification. Casting speed of AC4C strip could be improved up to 90 m/min by the effect of the semisolid strip casting. The microstructure of the strip cast from semisolid slurry was different from that of the strip cast from the molten metal. Primary crystal of the semisolid cast strip was spherical. Eutectic Si was very fine and globular. Mechanical property of AC4C strip after homogenization, cold rolling and T6 heat treatment was as below; UTS: 270 MPa, 0.2%proof stress: 190 MPa and elongation: 18%. The elongation was especially improved by the semisolid strip casting.

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In order to develop the high strength materials, the forming process with large strain is one of available processes. The repeated shear deformation process with side-pressure under high hydrostatic pressure had been developed by the authors. In this study, the 0.15%, 0.25%, 0.50% and 0.85% carbon steels are deformed by shear deformation process, and the properties of materials such as Vickers hardness, tensile strength and microstructure observation were investigated. The 0.50% carbon steel specimen was pressed without rotation (route A) or with rotation of 90° after one pass (route C). It was possible to deform by repeated shear deformation process without any failure for all carbon steels. After 3 passes of shear deformation, microstructures of all carbon steel were refined. Vickers hardness and tensile strength increased with increasing number of passes.

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This paper describes a new biomachining method by using microbially influenced corrosion. Differences between mild steel and copper in the metal biomachining through Thiobacillus ferrooxidans of a kind iron oxidizing bacteria have been investigated in three types of environment of 9K medium, the bacteria-cultured solution, and the cultured and sterilized solution. Losses in mass of SS400 by biomachining in 9K medium with the cultured solution were larger than those of copper. Losses in mass of SS400 and copper by biomachining in the cultured solution were respectively about 30 mm/y and 6 mm/y as the dissolved amount was converted into thickness. The surface of SS400 by biomachining was in rough compared with copper's in 9K medium and the cultured solution, that is the surface roughness of SS400 was abut 30μm whilst one of copper's was abut 3 μm.

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LIGA process becomes attractive for application to the industry thanks to its performance of fabrication with high aspect ratio and mass production. However, LIGA process is generally possible to produce only the 2.5-dimentional microstructures. So ,we proposed producing 3-dimentional microstructures by means of the combination of LIGA process and anisotropic etching which is suitable for mass production.

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Quasi-three-dimensional (3D) microstructure fabrication technique utilizing deep X-ray lithography (DXL) has been developed. In this technique, as the intensity distribution of the X-rays is controlled by a newly developed bending mirror, the exposure residual depth of polymethyl methacrylate (PMMA) resist is controlled over the exposed area. We also investigated the effects of controlling the beam intensity distribution for exposure changing X-ray mask absorber angle on the obtained quasi-3D resist pattern shapes. As the results. Quasi-3D PMMA pattern with inclined shape sidewall was successfully fabricated.

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The macroscopic and microscopic deformation was investigated on Pt_<48.75>Pd_<9.75>Cu_<19.5>P_<22> amorphous alloy, the material exhibits a Newtonian viscouss flow in the supercooled liquid temperature range above 503K (Tg:glass transition temperature). The microformability is evaluated by the geometrical transferability of the die shape to the material. V-grooved micro dies of (100)Si were fabricated by an electron beam lithography-nanometers to 1 micrometer. After the forming, the transferred shape of the material is measured with AFM. As a result, the material exhibits superior formability on nanameter scale and may be applied to micro/nano-forming of nano-devices.

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The micro-CNC-incremental forming system for foil materials was developed as a microfactory cell. The principle of this flexible sheet metal forming system is called incremental forming by hammering. Small increments of sheet metal bending and bulging deformation are generated by hammering. Repeated step-by-step cycles result in variously shaped shell structures without dies. To realize these systems, small actuators, such as piezoelectric actuators, small linear sensors, and an X-Y stage driven by ultrasonic linear motors, are selected. The dimension of a punch(tip of the hammer) is 10 micrometers in diameter. The hammer is installed at the end of the beam, and the beam (handle) is resonantly oscillated by a piezoelectric actuator. Using this system, we formed a 900mm long micro car body shell without dies in a scanning electron microscopic field of view.

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The new microforming system has proposed for metallic glasses under rapid heating. Metallic glasses exhibit the Newtonian viscous flow and the viscosity is much lower under rapid heating than that under a constant temperature in the supercooled liquid temperature range. As an application of this phenomenon, characteristic microforming should be performed at very high strain rates under very low stresses. In the present study, the new system was developed and furthermore, the glass transition and crystallization phenomena of Pt based metallic glass and the straining behavior under rapid heating were studied.

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Micro springs of Ni was fabricated by UV-LIGA(UV-lithography and electroforming) process. The spring was S-shaped and was 1 mm high, 0.85 mm wide and 50 μm thick. For the purpose of detecting the spring characteristics and fatigue strength, new testing machine was developed as a microfactory cell. This system is characterized by its static and dynamic, repeated loading mechanism. A moving coil electromagnetic linear motor is used as a loading mechanism, and the load is calculated by the current of the coil that is supported by a parallel plate spring structure. The displacement of the moving coil is measured with a linear differential transformer installed in the loading unit. Using this apparatus, we measured the spring characteristics and confirmed good agreement between the experimental and FEM-designed characteristics of the spring. The fatigue tests were carried out on the microsprings. As a result, this test system is useful for investigating fatigue strength and detecting microstructural changes.

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The X ray mask used in the present LIGA process has the uniform thickness of an absorber. Therefore, the resist patterning is the structure of the same depth form, and the fabrication of 3-dimensional microstructure is difficult. In this paper,we propose the procedure of 3-D micro processing by X-ray mask with optical intensity variation.

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Recently, optical components employing minute surface pattern in nm order have been manufactured in injection molding. Among the optical components, diffraction lens of printers and light guide panels used for liquid crystal displays require the precise transcription; however, the transcription mechanisms of these micro surface patterns has not been clarified in detail. It will be essential to establish the transcription model to predict the quantitative transcription property as a function of molding conditions, since the micro surface patterns will become high density and also require the precise transcription. Therefore, we have conducted the injection molding experiments to reveal the effect of molding conditions on the transcription property of micro multiple V-grooves. By measuring the transcription heights of the V-grooves fabricated under various molding conditions, we confirmed the following results: (1) The transcription ratio increases with increasing the mold temperature and the compression pressure; (2)The transcription ratio of small V-grooves are higher than that of large V-grooves whose width is about 0.1 mm.

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In general, deep microholes machined by EDM make machinig efficiency decline because the discharge becomes unstable by EDMed sludge stagnation. In this study, using ultrasonic vibration in machining fluid in order to prevent EDMed sludge stagnation, machining depth, machining rate and behavior of sludges were investigated. As a result of the experiment, the depth of microholes by EDM with ultrasonic vibration became as about two times as that without ultrasonic vibration and machining rate increased. It was observed that EDM with ultrasonic vibration promoted to reject the sludge around the hole.

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Round-to-hexagonal and round-to-octagon drawing of the S45C steel (JIS) and the copper wire has been investigated. Long-shaped products are characterized by a high surface quality as well as by a high dimensional accuracy. Many concepts, including the slab method, that are used in round bar drawing cannot be applied to the drawing of shaped wire. Round-to-shaped wire drawing has been_simulated by a 3D-FEM. In this study, authors drew the shaped wire from round wire by changing the die half-angle and one-pass reduction and examined the drawing stress, dimensional accuracy (diameter, magnitude of corner R) and residual stress. The results reveal that the optimal die half-angle for shaped wire drawing is slightly greater (α=10〜13° ) than that for round wire drawing and that the one-pass reduction is about 30% .

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In injection molding of an optical disk, toric lens, and so forth, their quality depends on the preciseness of the transcription of a minute structure on a mold surface. However, the transcription mechanism has not yet been clarified, because transcription is carried out in a very short time and the structure is very small, hi this paper, transcription properties have been examined using V-grooves of various sizes, machined on mold surfaces, and the following results are obtained. (1) Transcription properties have been clarified. (2) Transcription height changes with compression time tc, when tc is short. Therefore, tc should be more than 2.0s for fine transcription. (3) A mechanical model of the transcription process, in consideration of the strain recovery due to the viscoelasticity the property of polymer, is proposed. (4) Simulation results agree fairly well with experimental ones, indicating that the proposed transcription model is useful for brief estimation of the transcription properties prior to an actual injection molding trial.

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