Fatigue crack of pure aluminum plates with unique anisotropy propagated to rolling direction the made 30°to loading direction. The crack propagated as a mixed mode I + II crack. The effect of stress concentrations to fatigue crack were observed by conducting fatigue test on CCT specimens. The stress intensity factor (SIF) of the crack was analyzed by Finite Element Method (FEM) using the displacement extrapolation method. It is confirmed that even the stress concentrations exist and increase the SIF on the crack tip, if the SIF is still in the range of the SIF range of the crack that propagates to rolling direction (RD), the fatigue crack maintains to propagate to rolling direction. In case of specimen with rapid change of stress distributions, the SIF range of the crack that propagates to RD on specimens with stress concentrations is the same as that of specimens with no holes.

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A metal-ceramic crown used in the clinical stage is manufactured by burning 3 layers of the dental porcelain on the metal coping. Then the deformation of the crown occurs by a hardening shrinkage and thermal shrinkage of dental porcelain. Therefore, a study on deformation of the metal coping in production process of metal-ceramic crowns has been done by using the finite element method (FEM). As a result, the following conclusions were obtained. : (1) Neighborhoods of ends of the collar extended into outsides of the crown. In particularly, the largest deformation was observed at ends of the collar. (2) Extension of neighborhoods of end of the collar increased with increasing the length of the collar. (3) The thickness of the first layer of the dental porcelain was largely influenced in the deformation of the metal coping.

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Characteristics of singular field around interface edge between ceramic and soft metal interlayer around the corner and the mid region of the jointed beam were investigated experimentally and theoretically. Displacement fields around the interface edge were measured using laser moire interferometer displacement anlysis technique. The measured singular field around elastic/elastic-plastic interface edge was compared with theoretical results (elastic/linear hardening material interface edge prediction and elastic/power law hardening material interface edge prediction). The controlling factors for the singular field around elastic/elastic-plastic interface edge were proposed and its validity was examined. The influence of hardening properties of interlayers on the controlling factors were investigated experimentally and theoretically.

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The effects of the fillet, which was formed by melted brazing at the brazing temperature, on the residual stress in the Al_2O_3/Cu joints were studied by the finite element analyses. The stress distributions near the joining interface show that the brazing fillet can diminish the stress singularity at the edge of the joining interface. So an optimum design of the joint structure can significantly improve the strength of the ceramic/metal joint.

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The fracture strength of GFRP/stainless-steel adhesive joints was studied analytically and experimentally. Firstly, the stress distributions near the delamination edge were analyzed by FEM. The results showed that the shear stress and the normal stress distributions near the bonding edge can be expressed by two stress singularity parameters. Secondly, to measure the delamination initiation load, tensile shear tests were carried out on double lap joints and embedded joints. The experimental results showed that the delamination strength depends mainly on the shear-stress-singularity-intensity. It is therefore concluded that the shear stress dominates the delamination strength of GFRP/stainless-steel adhesive joints.

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The effects of the cast-iron microstructure on tribological properties were evaluated by a wear test between a wire rope and a cast-iron specimen. The test results showed that (1) a wear between the wire rope and the cast iron occurs under a boundary-lubrication condition and that (2) although the pearlite ratio in the specimen is high, low graphite nodularity in the specimen increases the wear of cast-iron.

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Variable loading fretting fatigue tests were performed using two-step multiple stress and SCM435 steel. Varialbe stresses used in the experiment consist of two stresses. One of them is a stress equal to fretting fatigue limit under full-reverse constant load. Another is chosen so that amplitude and mean are within the unbroken region in fretting fatigue limit diagram. Fretting fatigue failure occurred even if the variable stress didn't contain the stress above fretting fatigue limit under constant load. Consequently, fretting fatigue limit under variable load is considerably lower than that under constant load.

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Fretting fatigue tests of Al alloy in vacuum were carried out using a fatigue testing machine with SEM for in-situ observation of wear behavior. The plain fatigue life in vacuum was longer than that in air. The fretting fatigue life in vacuum was little longer than that in air. The reduction of the fretting fatigue life in vacuum is mainly because the tangential force coefficient increased in vacuum.

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To produce magnesium alloy with ultra fine-grain size, powder mixtures, which zinc and aluminum powder was added with various contents to turning chips of AZ31B alloy, were mechanically alloyed for various milling times. In the case of Mg-Al system, Mg_17Al_12 or Mg_2Al_3 phase forms by milling for long time, these phases consist of particles which crystalline size with nano-meter order. When Mg-Zn powder mixture was milled for long time, structure of the obtained powder consist of MgZn_2 phase. Icosahedron Mg_<49> (Al, Zn)_<32> phase, as called the quasi crystal, forms by mechanical alloying of powder mixture with molar ratio Mg : Al : Zn=4 : 3 : 3.

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Mechanically alloyed powder is active and it has high driving force for sintering. The mechanical alloying of mixture of AZ31 chip and aluminum or alumina powder with various compositions was performed using high-energy ball mill. The obtained alloy powder was constituted of structure with ultra fine crystalline size of nanometer order. The mechanically alloyed powder was bonded on surface of magnesium alloys (AZ31B and AM60B) at various temperatures and pressures by the hot pressing. The structural change and hardness distribution at the bonded part under various conditions in the hot pressing were investigated, in order to surface improvement of magnesium alloy using the mechanically alloyed powder.

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Powder mixture of pure Fe, water atomized Fe powder (0.63mass%O), pure Al, and mill scale Fe power (24.5mass%O) was milled for certain period. Powders were mixed to be the composition of Fe-40mol%Al and Fe-40mol%Al + 2.5 vol% Al_2O_3 after mechanochemical reaction. When the water atomized Fe powder was used for milling, about 2.6vol% Al_2O_3 will form after the PM process. Almost full density compacts are obtained by vacuum hot pressing under the condition of 1273K-150MPa-3.6ks. The compacts exhibits fine microstructure less than 100nm B2 (FeAl) and fine precipitation from EDS, TEM and electron diffraction. The carbide, Fe_3AlC_0.5 is formed during PM process and it located within and between the MA powder due to the addition of stearic acid as process control agent.

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To produce cast iron powder containing of fine-grained graphite particles, powder mixture of cast iron and graphite, which the graphite powder with various contents mixed to the cast iron turning chips, was mechanically alloyed for various milling times by high energy ball mill. The iron powder, which was contained high carbon, obtained by milling for long time. Heat treatment of the mechanically alloyed powder was carried out at various temperatures. The graphite phase with fine grain size forms in the iron matrix by the heat treatment at 1273K.

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Mg_2Si/MgO/Mg composites with graphite particles, using Mg, SiO_2 and graphite powders as the starting raw materials, were produced via the solid-state synthesizing process and the hot extrusion process. These composites, which have low-density, show good tribological properties. The result of wear test by pin-on-disk type tribometer under dry conditions indicated that both the fluctuation of the friction coefficients and the wear of ADC12 counter materials were remarkably reduced due to the lubricant effect by the dispersed graphite particles.

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Reaction and formation of Mg_2Si via spark plasma sintering (SPS) process has been investigated in this study. The elemental magnesium and silicon mixture powder was employed as starting raw materials, and those powders were mixed as the rate of Mg : Si=2 : 1. The powder mixture was refined and consolidated by repeated plastic working (RPW) then; SPS was performed to synthesize Mg_2Si at low temperature. As a result, it was understood that the crystallite size of Mg_2Si after sintering is controlled by the number of cycles of RPW.

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The Mg_2Si/MgO/Mg composites, which show excellent mechanical properties, have been produced via combination of solid-state synthesis and hot extrusion in preceding study. In this report, it is tried that the Mg-Si/SiO_2 mixtures are spark plasma sintered (SPS) to synthesize Mg_2Si/MgO after Repeated Plastic Working (RPW), which was performed to refine their particles and disperse homogeneously. Then, the hot extrusion was carried out at low temperature (350℃). It aims at not only avoiding growth of grains and particles with high pre-heating temperature as usual but also reduction of consumption of energy. Finally, the extruded Mg composites via SPS process were evaluated on the microstructures, hardness and strength.

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In recent years, magnesium alloy is frequently used for car components, computer parts and camera parts. However, a lot of magnesium dust made by the manufacturing process is dumped as industrial waste, because the surface area per unit volume is wide and the dust is easy oxidized during the fusion process. The magnesium dust might be able to be recycled by compaction forming for reducing the oxidation. In this paper, the compaction forming of the magnesium dust is attempted. For the compact obtained, strength test and check of the defect were performed. Furthermore, the melting experiment of the compact into fused aluminum was examined to apply the compact to the aluminum alloy additive.

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In order to develop the recycle process of the magnesium dust, compaction forming of the magnesium dust was investigated. In our previous paper, it was found that the magnesium dust was able to be formed by annealing treatment of the dust, or mixing of binder into the dust. The compact obtained was effective as the alloy additive in the fusion experiment of aluminum alloy. However, these treatments bring increment of the process. In this paper, the blending of another dust to the magnesium dust was attempted, and the compaction condition and the mechanism were investigated.

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The purpose is to develop the new commodities made by the Nachiguro stone powder and useful method for industrial field. In this report, we examined the suitable processing methods for the Nachiguro stone powder. At first, the processing methods used the spark plasma sintering and the electric furnace sintering methods.

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This paper aims to find the influence of Cu addition (replacing Ni fraction) up to 14% on mechanical properties and material properties of Ti-Ni shape memory alloy fabricated by pulse-current sintering method. The properties examined here are microstructure, the thermo-mechanical properties, the cyclic deformation characteristics and others. The temperature-response of the alloy was fairly improved by Cu addition. Increasing in adding amount of Cu resulted in a decreasing in the stress level at cyclic deformation testing. It was found that the cyclic deformation relatively made the thermo-mechanical behaviors of the alloy stable.

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In Micro Metal Injection Molding (μ-MIM), the feedstock properties, particularly particle size and shape, composition of metal powder are significantly important. The purpose of this study is to investigate the effect of metal powders on molding property, the quality of μ-MIM products and their microstructure. The three types of powder, i.e. 3μm and 9μm water-atomized powders and 3μm gas-atomized powder were used for experiments, and the melt viscosity of feedstock was compared. Then the spring shape of green compact specimens was produced by micro injection molding machine, and green density was evaluated. The effects of density and grain size of sintered specimen with various sintering temperature and time were discussed.

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Metal Injection Molding (MIM) is a comparatively new method of manufacturing metal parts, combining injection molding process with flexible formability and powder metallurgy. Metal injection molding of small parts is named "μ-MIM" and is considered one of premising process to manufacture micro parts for various applications. In this study, micro-size specimens were molded by using a micro injection machine, and the inside mold pressure and density of green compact were investigated. Then the effect of molding condition on the density of green compacts was discussed. As the result, the inside mold pressure was observed higher at the near-gate-side than the far-gate-side at any molding conditions. The density of green compacts was not affected by the injection speed, but varied apparently depending on the material temperature. It was confirmed that the micro injection machine has some advantages for producing μ-MIM products.

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A Micro Metal Injection Molding (μ-MIM) process needs more sophisticated techniques than the conventional metal injection molding. Especially, inhomogeneous state of feedstock will strongly influence on the quality of the final products. In order to evaluate the mixing and pelletizing conditions of the feedstock, we focused on the unit of pellet. In this study, the effects of homogeneity of the pellet on the mechanical properties of products were investigated. In order to fabricate the homogeneous pellets, pelletizing process was added. Homogeneity of pellets was evaluated by variation in density and binder fraction of individual pellets, that is, coefficient of variation (CV). Re-pelletizing process was confirmed to improve the homogeneity of pellets. Micro dumbbell specimen was fabricated and the CV for the specimen was investigated, the results showed that the properties of micro dumbbell specimen were improved by re-pelletizing the pellet.

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Selective Laser Sintering is one of the rapid prototyping technologies in today's market. It has attracted much attention and interest since the introduction of metal object fabrication by metal layer sintering. The success of this technology mainly lies in its ability to fabricate objects of complicated shape in a shorter time and at lower cost. However the complexity of new metal object design has reached a level where some special-shaped objects cannot be fabricated without post-infiltration joining due to process limitations. This paper studies the feasibility of using the brazing process to join sintered parts fabricated by the selective laser sintering method. Suitable brazing metals were chosen by the wettability test and an application example of the fabrication of a new model heat exchanger is discussed.

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Surface cracking or delamination of the top ceramic layer in metal/ceramic graded powder compacts is one of the problems when functionally graded materials are fabricated by sintering. To reduce the internal stress in powder compacts during sintering, uniaxial pressing by weights is studied. Change in stress distribution due to compressive loads is analyzed by the finite element method for sintering. Non-uniform sintering shrinkage in the powder laminates produces in-plane tensile stress on the top surface, which consists of the mismatch stress and the bending stress. Uniaxial pressing is effective in reducing the tensile bending stress on the top surface when the powder laminates warp downward. The axial tensile stress around the edge of the laminates, which may be the cause of delamination, can be also decreased by pressing.

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The effect of shape of stirring blade, the viscosity and ultrasonic vibration on the homogeneity of microstructure was investigated by visualized modeling of stir casting process using water and glycerin. Then aluminu m and magnesium ally matrix composites was fabricated under the condition obtained by visualized modeling. The paddle type stir blade and the utilizing of ultrasonic vibration have good flow patterns for homogeneous distribution of the reinforcement in the composite bullet.

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The fatigue crack growth behavior in SiC (SCS-6) fiber reinforced Ti-15-3 matrix alloy composite subjected to a constant tension-tension loading mode was studied using single edge specimen in 2×(10)^<-3> Pa vacuum at 293 and 823K, with a frequency of 2 Hz, and a stress ratio of R=0.1. Direct measurement of the fatigue crack length, and the crack opening displacement along the crack wake during the test were carried out by SEM. The increase in the test temperature was found to lead to a decrease in the fatigue crack growth rate. The degradation of bridging fibers in the crack wake was severe for T=293K, and this behavior was dependent of the test temperature. The crack opening displacement along the crack wake tested at T=823K decreased with increasing crack length, and this tendency is dependent on the applied stress range. The associated increase in the crack tip shielding is explained on the basis of the crack closure due to the matrix relaxation by fatigue creep and the interface wear behavior.

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Creep damage of SiC particle reinforced A6061 aluminum alloy, with various volume fraction of particle SiCp/A6061 composite, has been studied. Unloading modulus was measured from the unloading stress-strain curve at arbitrary creep testing time, during creep test for the qualitative assessment of creep damage. Densimetric change of the composite was also investigated and found to be associated with microstructural aspect of debonding at matrix/particle interfaces and cracks within SiC particles. The unloading modulus decreased with increasing creep time and with decreasing change of density of the composite. Damage parameter was found to have good relative correlations to unloading modulus and creep strain. The damage parameter derived from unloading modulus was formulated by a unique equation as a function of creep strain independent of the volume fraction of SiC particle. It has been concluded that unloading modulus was applicable to quantitative assessment of the creep damage of SiCp/A6061 composite.

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Carbon fiber reinforced carbon matrix composite materials (C/Cs) possess excellent properties at extremely high temperatures. Among them, the most advantageous is to hold the high strength-to-weight ratio at extremely high temperatures. However, we can hardly say that mechanical properties of C/Cs are well understood. The compressive strength of C/Cs is one of such properties. Concerning to compressive failure, even the test method has not been established. The object of the present paper is to establish testing method of compressive strength from room temperature to extremely high temperatures. Thus, compressive tests of C/Cs were performed using various shapes of specimens without supporting jigs so as to find effective specimen type for high temperature tests. Then, using optimized specimen, the compressive strength of a 3-D C/C was determined as a function of temperature up to 2000℃. It was found that the compressive strength of the C/C monotonically increased with temperature. This enhancement was shown to be brought by enhancement of the fiber/matrix interface.

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Carbon fiber / metal matrix composites were fabricated by powder metallurgy process to achieve high thermal conductivity. The pitch based carbon fibers were mixed with aluminum or copper powders by 40 vol.%. The mixtures were consolidated by pulse current sintering. The resultant sintered bodies were subjected to swaging to orient the carbon fibers in the composites. Hellman's orientation coefficients of the composites with swaging process were estimated to be 0.9 for both Al and Cu matrices composites. This value means almost complete parallel orientation of the fibers. The thermal conductivity of the Al or Cu matrix composites was improved with the fiber orientations. The conductivities of Al and Cu composites were 217 and 393 W/ (m・K), respectively.

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The damages of brittle materials (alumina-carbon refractories) subjected to compressive stress or thermal shock were evaluated using ultrasonic pulse-echo method. The changes of the wave propagation velocities obtained from the base-reflected echo were in good correspondence with the damage processes of the used materials under uniaxial compression test. It was found that the intensity of the peak frequency of the back-scattered waves analyzed by FFT decreased as the damage progressed. In compression test, damages occurred even in unloading process. In the specimen damaged by thermal shock, the greater the equivalent normal stress became, the greater the damage did in tensile stress region. It was found that even in compressive region, damage was observed to some extent.

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Bamboo is treated by solution of sodium hydroxide to extract bamboo fiber. The alkaline treatment of bamboo is performed at several conditions, which are the concentration of sodium hydroxide solution, 0.5 to 2.0% and treatment time, 10 to 150 minutes. The diameters of bamboo fiber obtained by alkaline treatment are 0.2 to 0.8mm. The required treatment time to obtain bamboo fiber decreases with increasing concentration of sodium hydroxide solution. Tensile test is conducted to investigate the tensile properties of bamboo fiber. The tensile strength of bamboo fiber after the treatment can be obtained as before the treatment.

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This paper describes creep rupture model taking into account the stress concentration on adjacent fibers and the propagation of interfacial debonding (PID) around broken fibers in unidirectional composites. The stress concentration makes an adjacent fiber break, and leads to clusters which are correlated breaks in the nearest intact fibers within the same cross section. The interfacial debonding is accompanied with the fiber break under the tensile load, and it grows in creep. We simulated the creep rupture time using 3D shear-lag model taking into account the stress concentration. We performed a fragmentation test by the use of VE resin embedded a single ECR-glass fiber to investigate the PID behavior. And we proposed the creep rupture model taking into account the PID. For result, a creep rupture time does not depend on the PID, because in this study the PID is very small on ECR-glass/VE.

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The thermoplastic Poly-ether-ether-ketone (PEEK) is a kind of heat-resisted plastics, and recently come into using with CF/PEEK (Carbon Fiber Reinforced PEEK) in high temperature. In this study, purposes were to mechanical properties by the three point bending creep test. As a result, the longer heating treatment time was, the more crystallinity was increased, and when they were crystallized at 300℃. Then bending creep behavior was suppressed with crystallinity increasing, and this tendency was significant at longer test time. And Arrhenius reciprocation of time-temperature formed, and master curve could be made.

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An evaluation method for fatigue damage of FRP (Fiber reinforced plastics) has been investigated by measurement of crack amount on specimen surface. Using SMC (Sheet molding compound), a kind of FRP, tensile-tensile fatigue test with approximately 1Hz cycle has been carried out. For dispersion of a value, evaluation for an individual crack such as number of cracks, mean length of cracks and crack length distribution are not suited for specification of a damage state. Although using comprehensive method like crack density, there are little difference of increase tendencies by various stress level. Based on this result, it is concluded that fatigue damage state can be specified by measurement of crack density.

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This paper presents characteristics of fatigue in quasi-isotropic graphite/epoxy laminates, [45/0/45/90] s. Tension-tension fatigue loading with the stress ratio R=0.1,was applied to get the S-N diagram. During the fatigue tests, the cumulative damage evolution was photographed microscopically certain fatigue stages to make clear the fatigue mechanism. It was found that S-N diagram was linear in the range of this study. For the progression of the transverse crack and the delamination, it was found that the transverse cracks in the 90deg layer were saturated at an early stage, but that those in the 45deg and the-45deg layer and the delamination in the all layers were increased gradually. It was suggested that the delamination between the 45deg and the 0deg layers plays a important role for applying the Palmgren-Miner's rule for this laminates in this paper.

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We investigated fatigue life and rupture mechanism of acrylonitrile-butadiene-styrene terpolymer (ABS) and polyethylene terephthalate (PET). Striation was observed in fracture surfaces of ABS. Fracture surfaces of PET showed cup & corn type. Fatigue crack initiated in the interior of the specimen at high stress amplitude. It is due to the effect of tri-axial stress. Fatigue crack started from the surface of the specimen at low stress amplitude. There were difference in the details of fatigue crack behavior between polymer alloy (ABS) and single polymer (PET).

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The ring burst test equipment developed by one of the authors was used to evaluate the fatigue strength of FW-FRP ring specimens in the hoop direction. In the new equipment, flat cage (needle bearings) were used to reduce the friction between the rod and the segments. The specimens used were T700S/epoxy, CFRP rings. During the fatigue tests, matrix cracking at the surface resin rich layer and delamination from the tips of the matrix cracks were observed. This behavior is similar to the damage progress in the FRP pressure vessels. It is proved that the present test system was available for estimating the fatigue strength of the FRP pressure vessels in the hoop direction.

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For a use of filament winding reinforced plastic cylinders (FW・RP cylinders) with a circular hole, it is necessary to get a fundamental data for mechanical design of structures transmitting torque power. Therefore, the torsional rigidity of FW・RP cylinder with a circular hole in a diameter a=0,1,2,4mm were calculated against a fiber orientation direction θ=0&acd;90° and a fiber volume content V_f=35&acd;75% by using the finite element method (FEM). As as a result, it was found that the torsional rigidity of FW cylinder with a circular hole remarkably dropped near the hole. Moreover, this trend was good agreement with data obtained by static torsional tests.

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In this paper, the effects of post-cure on mechanical properties of plain woven glass fabric composites are investigated by means of the tensile test. The post-cure of composites was carried out in order to the post-cure duration at the constant temperature; 80℃ for 4,8,12,16,24h and non post-cure. It is found from the experimental results that the tensile strength and Young's modulus increased due to the post-cure. The stress-strain relation of post-cured specimen becomes linear due to increasing the adhesive strength of the fiber-matrix interface. It is clarified that the knee point stress of non post-cured specimen was higher than that of post-cured specimen. Transverse cracks are observed by the optical microscope to reveal the effect of post-cure on fracture behavior. It is found that transverse cracking in post-cured specimens initiate at higher strains than the strains in non post-cured specimen.

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Acoustic Emission (AE) characteristics of micro-failure process in short fiber reinforced polycarbonate were studied. Matrix cracking, fiber/matrix interface debonding, and fiber breaking occurred complicatedly and in connection with each others. Representative AE frequency depends on Elastic modulus and density of fractured materials. Therefore, it is possible to distinguish matrix cracking and fiber breaking in composite by AE frequency analysis. The other side, fiber/matrix interface debonding has AE frequency both matrix and fiber. So, in this paper, three characteristic AE frequency bands to recognize these micro-failures were specified by using model specimen. Furthermore, studying power of these frequency bands in composite for strain, behaviors and occurrences of three micro-failures were discussed.

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It is attempted to substitute the cylinder made by the tape winding method (TW・RP cylinder) for that made by filament winding method (FW・RP cylinder) as a shaft material, because it is easy to produce the cylinder by the tape winding method than the filament winding method. Therefore, 3 point bending and 4 point bending tests were carried out by using the TW・RP cylinders with several fiber orientation angles and several wall thicknesses in order to study mechanical properties of the cylinder. Moreover, the process of destruction was examined through surface observation of the specimen. As a result, the effect of the fiber orientation angle, wall thickness and testing method on bending property was observed.

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Carbon nanotubes (CNTs) are expected to be a new functional materical. We studied fabrication of polystyrene (PS) and polypropylene (PP) matrix composites filled with multi-walled carbon nanotubes (MWCNTs) and vapor grown carbon fibers (VGCFs). Specimens were fabricated by injection molding. Young's modulus and tensile strength of the molded specimens were measured and the effects of filler content and it is two times larger than that of bulk PS and bulk PP. Tensile strength of CNT/PP composites increases with increasing CNT content and it is two times larger than that of bulk PS and bulk PP. Tensile strength of CNT/PP composites increases with increasing CNT content but that of CNT/pp composites slightly decreases. As the result of discussion about the surface treatment to CNTs, it was suggested that tensile strength of CNT/polymer composites improves by metallic coupling to CNTs.

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In this study, polymer system porous membrane was molded by extracting the soluble particle in boiling water, after it molded polyvinyl alcohol and water-soluble particle like the sugar by blending in UHMWPE. The following were carried out : Water permeability test of the porous film and the performance evaluation. It was possible that the water permeation quantity was made to change by UHMWPE and compounding ratio of the water-soluble particle. The water permeation quantity was affected by changing the particle size of the mixture. The water permeation quantity influences in the difference between the procedure in the case in which it is rolled, after the water-soluble particle is removed, and case in which it is removed after the rolling for the molding.

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Glass fiber reinforced plastic (GFRP) has many useful characteristics, but there are many problems to dispose of it. One of the methods to adjust this problem is material-recycling by carbonization. It was the purpose of this paper to develop the materials with the electromagnetic shielding effectiveness by carbonization. It was considered that two-step heat treatment was available for carbonization. As a result, the material created by heat treatment of 900℃ or more showed electrical conductivity, and was able to be used as the electromagnetic shielding material.

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We experimented creep tests of polycarbonate (PC) and polymethyl methacrylate (PMMA) at constant applied stress. The creep curves of PC and PMMA depended on the temperature and stress. The lives of both polymers were expressed by the following equation. t_<&ipartint;>&vprop;σ^<-n> The values of n depend on the temperature. They were reduced near the glass transition temperatures.

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In this study, debonded particles in a random particulate composite are analyzed by three-dimensional finite element method to investigate their load carrying capacities, and the way to replace a debonded particle with an equivalent particle is examined. The variation in Young's modulus and Poisson's ratio of a damaged composite with the increase of the debonded angle was evaluated for different particle arrangements and different particle volume fractions, which in turn compared with the results by equivalent inclusion method. Consequently, it was found that by replacing a debonded particle with an equivalent orthotropic particle, the macroscopic behavior of the damaged composite can be reproduced, although the interaction between neighboring particles should be considered with increasing the particle volume fraction.

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Nowadays, it seems that Dry and MQL cuttings instead of Wet cutting are usually used in machining field. This report shows that the flank aspects of TiAIN coated long drill is compared with each case. Chip formation's difference in each case is almost nothing. However, the flank surface of Dry cutting drill is different from others and has the wide area of little sticking work material. It is supposed that the initial difference of cutting behaviors causes the total performance of each cutting case.

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