The authors are attempting the identification of damaged unit in Advanced Grid Structure (AGS), whose ribs are made of carbon fiber reinforced plastic (CFRP) unidirectional laminates, by monitoring strain conditions using fiber Bragg grating sensors embedded in all ribs. In this research, three ・point bending tests were conducted to an intact specimen and a damaged specimen in order to investigate whether a strain distribution changed when a damage appeared in the AGS. Then, for the simulation of the strain distribution in the damaged grid structure, two types of analytical models were investigated; equivalent stiffness model (ESM) and exact model.

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Health monitoring technologies are very important for improving the safety and durability of composite structures. FBG sensors are candidates for sensing devices for health monitoring. In this research, small-diameter FBG sensors were embedded in CFRP layers in a filament wound composite tank. Real time strain measurement of the tank during cure process and pressure test was performed by using the wavelength shift of the reflection light from the FBG sensors. Furthermore, the detection of microscopic damages was attempted by the observation of the deformation of the reflection spectrum.

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In this study, we have developed a new sensing system for simultaneous measurement of strain and vibration using optical fibers. This paper subscribes experimental and theoretical studies on measurement of acceleration by using the sensors. Two sensors, which have different beam length, were used. From the results, it appeared that the sensor has the ability of acceleration measurement.

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This paper describes application of the interphase forming/bonding method to embedding fragile functional fibers such as a Fiber Bragg Grating sensor and a titanium wire with its oxide on the surface in an aluminum matrix to develop a new type of material system. After high temperature stability of the FBG sensor was investigated, it was successfully embedded in the aluminum matrix by the method using a copper insert without losing its functionality. The titanium wire was also successfully embedded in the aluminum matrix by the same method without breaking the surface oxide, which enabled to obtain a multifunctional metal-based comnosite.

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In recent years mechanoluminescence (ML) materials attracts attention. New ML material SrA12O4^Eu with remarkable upgrade in ML intensity is developed by Xu et.al. It emits an intensive and repeatable ML during elastic deformation without destruction. In this study, influence of the stress exerted on the luminescence characteristic of ML powder mixed with epoxy resin was investigated. Moreover, realization of visualizing of stress distribution was also considered.

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A method to measure the residual stress around the fiber of the smart materials of fiber reinforced composites presented in this study. The residual strains (stresses) around the fibers are released by pushing the fiber out. The released residual strains are measured using an electron moire technique, which can fabricate grids with frequencies up to 10,000 lines/mm on the composites surface so that a displacement sensitivity of lOOnm can be achieved. This method can be applied to almost smart materials using the optical fibers and the fiber-reinforced composites, such as fiber-reinforced plastics (FRPs). Measurements of the interfacial residual stress in SiC/Ti-15-3 and boron/epoxy composites show the validity of the method.

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The possibility to detect the phase transformation of stress-induced martensite in ferromagnetic shape memory alloy Fe-30.2at%Pd thin foil was investigated by using Barkhausen noise (BHN) method. Stress-induced martensite twin was observed by laser microscope above loading stress of 25 MPa. BHN caused by grain boundaries appears in the lower frequency range and BHN by martensite twin in the higher frequency range. The envelope of the BHN voltage as a function of time of magnetization shows a peak due to austenite phase at weak magnetic field. The BHN envelope due to martensite twins creates additional two peaks at intermediate magnetic field. BHN method turns out to be a powerful technique for non-destructive evaluation of the phase transformation of ferromagnetic shape memory alloy.

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Our laboratory crew have been researched the functional properties and the mechanical properties of thermoelastic and magnetoelastic Shape Memory alloy applied by Rapid-Solidification method. When thermoelastic SMA composition is Ti-rich 50Ti-40Ni-10Cu(Ti54Ni40Cu6), we accomplished better SM properties using the nano thin plate precipitates and non-equilibrium phase. While, Spark Plasma Sintering(SPS) method was applied these rapidly solidified(RS) ribbons to make the bulky and most suitable sensor/actuator materials with higher power and larger volume for wider range of engineering application. This research is to manufacture high-performance RS-ribbon, furthermore SPSed RS-ribbon, and measuring lots of these performances.

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A light metallic closed cellular material has been developed. Polymer particles coated with a pure aluminum layer using a physical vapour deposition system were sintered by a spark plasma sintering method and polystyrene foamed particles coated with nickel-phosphorus alloy layer using electro-less plating were pressed into the green pellets and sintered at high temperatures in a vacuum condition. Metallic closed cellular materials that have lightweight were then fabricated. The compressive tests were carried out to measure the mechanical properties of these materials. The results showed that these light metallic closed cellular materials were brittle and do not have long plateau region.

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Development of higher performance and active actuator/sensor materials is most important to intelligent/smart technologies. Most of solid-state actuator/sensors has some relation with phase transformation during energy conversion between physical properties to mechanical stress/strain actuation. These are called as ferroic materials. In this paper, our recent study on developing new ferroic actuator/sensor and more advanced multi-ferries approach will be presented.

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RIO-DB (Research Information Database) is multimedia database that is accumulated by many AIST (National Institute of Advanced Industrial Science and Technology) R&D projects. Knowledgebase of underwater cutting technique is part of the underwater processing technique database that is developed and released as one of RIO-DB project. Authors have preserved the experimental data necessary for development of practical underwater mechanical processing to construct, to demolish and to maintain structure. Many movies and pictures of welding and cutting process have been conserved in this knowledgebase from the viewpoint of importance to understand phenomenon in the process. In addition to an abridgement and a basic version of the knowledgebase, we provide the detailed version that more information is accumulated and the user interface is improved. In this paper, we make a summary report of the progress and future developments of this project.

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The technology using the cavitation jet stream in water jet is applied to various fields. In this research, the cavitation jet stream was applied to ballast water processing of a vessel, and the validity to plankton processing was examined. It is found that there is an optimal injection pressure and an injection time for performing plankton processing. Moreover, the low pressure of 2MPa with a round shape nozzle can mostly annihilate planktons.

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The amounts of ultraviolet rays emitted during the arc electric discharge in which a carbon nanotube and a mesosize particle are formed were measured. It became clear that there were few amounts of ultraviolet rays, when a mesosize particle was generated, while the amounts of ultraviolet rays emitted were abundant, when a carbon nanotube was generated. The ultraviolet rays emitted at the time of arc electric discharge is related to the self-organization and the generation of nanotube and mesosize particle.

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The effects of nitrogen on localized corrosion resistance of HNS developed at NIMS were investigated in terms of crevice corrosion in artificial seawater at 35C. Synergistic effect between N and Mo was also discussed. High nitrogen steels containing molybdenum showed crevice corrosion resistance superior to that of molybdenum-free steel. Possible mechanism of improvement of localized corrosion by N alloying was also discussed. It was found that not only the buffer effect of pH by ammoniac ions but also inhibitor effect by nitrate ions played important role for improving localized corrosion property of HNS.

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In aluminum alloy die castings under cyclic load, a fatigue crack initiates at casting defect and propagates according to Δ-da/dN relation. The prediction method of fatigue life of aluminum alloy die castings under complex cyclic load has been proposed theoretically and verified experimentally. The paper shows that the prediction method is a so effective to a part with complicated shape as well as a round bar specimen.

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This paper intends to explain the mechanism of crack propagation and branching in fixed-sided plate, paying attention to its surface roughness and kinetic, dissipative energy. First, considering 2 dimensional problem, the surface roughness, defined using crack path length, and micro propagating velocity, which is along the crack path, can give the upper limit of the feasible kinetic energy. In addition, assuming that the dissipative energy is proportional to surface roughness, we can get 2 dimensional model of branching. Then from the 2 dimensional model, semi 3 dimensional model can be deduced, and comparison of this model with the experimental result of PMMA shows some difference, which is due to existence of discontinuity on actual surface toward the thickness direction. To deal with this problem, correction of semi 3 dimensional model is considered.

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One of the important subjects is the impact energy absorption system applied to the aircraft structure in order to keep the safety of human beings under the aircraft crash landing circumstances. For this purpose, the improvement of major energy absorption component such as landing gears, sub-floor structures and crew seats are necessary for rotorcrafts and light aircrafts. The focus of this study is the design and testing of structural element for sub-floor structures. Some energy absorbing structural element concept (the square taper tube, the triple square tube) together with some initiator concepts (film type, hole type) are examined on static characteristics. The result is evaluated based on specific energy absorption and load uniformity ratio. The square taper tube with the film type initiator possesses acceptable crash behavior.

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Two types of calcium phosphate ceramics, hydroxyapatite and tricalcium phosphate, were sintered with Spark plasma sintering (SPS) technique. Sintering condition were investigated and sintered body of these calcium phosphate ceramics were obtained with SPS technique. Four points bending tests and indentation fracture tests were conducted to charactrize the mechanical properties. Bending strength was lower than the previous studies. This is attributed to the initiation of microcracks during cooling process.

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Aluminum and zinc powders were mixed with various contents to magnesium alloy (AZ31) turning chips and then the powder mixtures were mechanically alloyed (MA) for various milling times. Structure of the obtained MA powder was analyzed by X-ray diffraction (XRD), for investigation of alloying process. Mg_<32>(Al,Zn)<49> phase , as called quasi-crystal (Q.C.), formed in the MA powder with Mg-(20〜40)mol%Al-(1O〜40)mol%Zn compositions. Mg_<17>Al_<12> phase also forms another Q.C. phase in MA powder with high contents of magnesium, and MgZn_2 phase also forms in MA powder with high contents of zinc.

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Aluminum and alumina powders were mixed with various contents to magnesium alloy (AZ31) turning chips, the powder mixtures were mechanically alloyed (MA) using planetary ball mill. The obtained alloy powder was bonded to magnesium alloy by hot-pressing at heating Temperatures of 673K〜773K under 200MPa. Mg_<17>Al_<12> phase precipitates from super-saturated α-Mg phase in the alloy layer bonded Mg-Al_2O_3 MA powder. In the case of Mg-61.5mol%Al MA powder, the amorphous phase transforms to Mg_2Al_3 phase by hot-pressing. When hot-pressing at high heating temperature, MA powder bonded to AZ31 by diffusion mechanism.

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From the aspect of production engineering, forming processes of metals, alloys, oxide glasses, metallic glasses and polymers offer a significant advantage in productivity and enable mass production of nanoVmicro-machines (NEMS, MEMS) and devices with controlled quality and low cost. Metallic glasses exhibit perfect Newtonian viscous flow in the supercooled liquid state and excellent micro/nano-formability under very low stresses. The present paper describes the fabrication technique of nano-structures by superplastic nanoforming with nano-scale die of glassy carbon and Zrbased metallic glass fabricated by focused-ion-beam(FIB) technology. It was found that nano-formability of Pt'based metallic glass with Zrbased metallic glass dies is better than that forged with glassy carbon dies. Dies and the die forged 100nm-module micro gear, 200nm-width logo characters are demonstrated.

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The kitchen knife for SASHIMI with long blade has an ability to cut a fillet offish with much moisture and fat which make cutting difficult. In this paper, the cutting process using a kitchen knife is examined and clarified the effect of long sliding along the cutting edge on cutting force and cutting surface. In cutting tests, test knife is made like knife for SASHIMI and for using with test machine. And that cut expanded polystyrene and urethane on some horizontal cutting speeds. Results are as follows: (1) In cutting test using expanded polystyrene, in case of faster horizontal cutting speed, vertical cutting force is small and well-cutting is got. (2) In cutting test using urethane, test knife can cut or not is divided by horizontal cutting speed.

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Injection-compression molding of large size molded products requires the elaborate consideration for multi gates designing and adjustment to control resin filling balance, although stable molding is still difficult if waste or composite plastics are used as materials, which have unstable fluidity. Our research aims at the flexible resin filling flow control by die tilting in injection-compression molding. In this paper, the effectiveness of die tilting is verified in an actual molding machine, and the effects of tilting angle and resin fluidity on the filling balance are examined in a testing machine. It is found that the flow balance varies linearly with the tilting angle and is independent of the fluidity.

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A new industrial process which enabled a continuous pressurized sintering of metallic powder was examined. A unique open mold with a shoulder in its sintering room was proposed so as to ensure suitable pressurizing to material powder in the continuous process. Tin powder was sintered continuously according to the proposed process, and it was confirmed that the pressure was worked stably to powder during sintering. This sintering brought a successful production of a tin rod which achieved the relative density of 99%. It was indicated that the proposed sintering system had the potential for continuous production of dense and homogeneous metallic rod.

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During sintering of metal/ceramic functionally graded materials, cracks often appear on the surface of the top ceramic layer due to the internal stress produced by mismatch shrinkage and warpage in multilayers. The ways to reduce the internal stress in the graded powder compacts are examined by using the analysis of sintering process. Thinning the top layer is found to be effective in reducing the tensile stress on the surface when the sintering properties of some layers are modified appropriately. The suppression of the surface cracking in the improved graded powder compacts is verified in experiment.

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Selective laser melting method is a technology of 3D fabrication by repeating the process that laser is irradiated on the metal powder selectively for the production of a thin sheet. SLM method is a promising technology for dies manufacturing. In the present study, SKD11 powder with an average particle size of 9.6^m was used and the influence of working conditions such as laser power and pulse frequency for mechanical properties were investigated. From the experimental results, it is obtained that the relative density is about 70%, and micro-Vickers hardness is 580Hv that is about 80% of bulk one. The fabricated model is 0.5mm in width and 0.2mm in height larger than estimated ones.

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Sintering and lamination characteristics of Fe-Cu atomized powder have been investigated to meet requirements on recycling of automobiles and manufacture of lightweight structure. The greentape laser sintering method using Nd:YAG pulse laser and powder tape called "greentape" is employed for the fabrication of Fe-Cu porous structure. Extensively investigated is influence of copper content and laser parameters, such as voltage, pulse width and average power, upon the state of liquid sintering or both surface texture and tensile strength of the sintered specimens. A gas-atomized Fe-2mass%Cu powder (20um in mean diameter) is superior to the Fe-15mass%Cu one in monolayer tensile strength, but contains many pores. It is successful to laminate 16 layers of the greentape (190 jam in thickness each) at a voltage of 198V, a pulse width of 2.0ms and an average power of 13W. Porous structure can be controlled by altering these laser parameters as well as by varying copper content.

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The purpose of this research is to develop new commodities made of the Nachiguro stone powder and useful method for industrial field. We examined several processing methods for the Nachiguro stone powder. When the Nachiguro stone powder was sintered in the atmosphere using the electric furnace, it became the brown sintered object. On the other hand, the Nachiguro stone powder was sintered in the reducing atmosphere that used carbon powder. The sintered object with the same color as the Nachiguro stone was manufactured.

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Composite material using coal ash and clay were investigated in terms of mechanical property. From the schrinkage to the mold dimention, the optimum sintering temperature were determined with changing the firing temperature. Adding the clay amount to fly ash, the effect on shrinkage and the micro vickers hardness were investigated. As a result, because of clay melting phenomena beyond the 1473K, the sintering process during ash particles occurs on smoothing, and the hardness increases by clay amount. Composite material of ash, clay and sludges were drasticaly improved on the hardness at firing temperature 1673K.

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Cu-Sn sintered materials were developed by utilizing bronze machined chips. The bronze chips, which were produced by dry-turning of BC3 bar, were mixed with electrolytic copper powder and atomized tin powder. The mixed powders were cold-compacted and then sintered without pressure. The limit of mixing amount of the chips to produce green compacts increased as the size of chips decreased. The sintered density and mechanical properties increased as the mixing amount of chips increased up to 10mass%, but decreased slightly above 10mass%. There was no significant influence of size of chips on the sintered density. Cu-10mass%Sn-20vol%graphite sintered composites, which contained not only the bronze chips but also copper-coated graphite powder, showed low wear and friction under dry sliding conditions.

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Mg-Si alloy have high potential as heat resistant light metals because Mg2Si exhibits a high melting temperature, low density, low thermal expansion coefficient, and a reasonably high elastic modulus. However, ingot metallurgy Mg-Si alloy showed very low ductility and strength. Then, by applying the solid-state formation of Mg_2Si by spark plasma sintering, magnesium composite alloys, including a large amount of Mg2Si particles, were fabricated. The density of the sintered Mg-Si alloy decreases with the increases of addition of Mg2Si. However, the elastic coefficient of them increases with increase in the amount of the additives.

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Technology transfer of the university seeds on materials and processing of the advanced magnesium alloys to industries was discussed, in employing matching fund scheme. The applications of core technologies, promoting the high-performance of them via microstructures control such as grain refinement, solid-state synthesis of Mg_2Si dispersoids, and hot extrusion, were introduced. In particular, the scale-up equipments and processing oriented to mass production were developed to fabricate large half-products; magnesium alloy rods, bars, and pipes. Patent pool system was employed in this R&D program to assist the effective and useful technology transfer of university seeds including intellectual properties, technical and market information.

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Micro metal injection molding, μ-MIM is hoped to be one of manufacturing process for minute metal parts in various engineering fields. he size of μ-MIM products is generally smaller than the size of feedstock pellets. Thus, it is deemed preferable that the capability of injection molding machine is commensurate with the amount of specimens. In this study, minute mixing-injection molding machine which is capable of producing with equivalent amount to a pellet was developed In order to show the advantages of the machine, other two types of injection molding machines for mass production; 1) Conventional injection machine, and 2) Micro size injection machine with similar micro cavities were also used for comparison. The effects of molding conditions on the properties of μ-MIM products were discussed. It was clarified that the minute mixing-injection machine developed is suitable for fabricating μ-MIM products.

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The production method for metal components with micro sized porous structure has been developed by applying "powder space holder method" to metal powder injection molding process. In this study, the green compacts with fine and coarse particles of SUS316L were prepared by hot press molding, and the effects of size and contents of space hold particles on the microstructure, sintered shrinkage and porosity were investigated. Moreover a co-sintering process was utilized to make a plate of sintered metals with micro porous graded structure. The five layers of metal with symmetric structure, which the skin layer was formed with high density metal and the core was formed with open or closed porous structure, or with inverse symmetry, was obtained by changing stacking sequence in co-sintering process. Mechanical properties of the materials with plain homogeneous porous structure and porous graded structure were compared. The usefulness of proposed method for producing the metal components with micro porous graded structure and the effective of graded structure to compensate the deficiencies on the mechanical property of porous metals was shown.

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In this study, the micro metal injection molding method inserted plastic sacrificial mold was proposed in order to solve some problems, such as filling in narrow cavity, poor mold transcription, difficult de-molding and handling operations, etc. in micro metal injection molding (μ-MIM). Using the minute mixing-injection-molding machine, PMMA sacrificial mold with the zigzag spring shaped micro cavity and the green compact were prepared by sequential 2-step injection molding method. Molding properties of PMMA sacrificial molds and the green compacts were evaluated.

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The low structural mass fraction required for future aerospace vehicles necessitates the development of new materials having improved specific properties at elevated temperatures. Fiber-reinforced titanium matrix composites (TMC) offer significant improvements in strength and stiffness over their monolithic counterparts and are prime candidates for these applications. This study was undertaken to investigate the effects of TMC processing on the axial tensile properties of unidirectional SCS-6/TJ-6A1-4V titanium matrix composite. The composite was manufactured by using spark plasma sintering (SPS). The TJ-6A1-4V powder and SCS-6 fiber mats were consolidated by SPS at the temperature of 800, 900 and 1000℃, and at pressure of 30 and 60 MPa in vacuum. The tensile specimens of TMC were tested in air at room temperature, 400℃, 600℃, and 800℃. The reactions and microstructures were studied in interfaces between SCS-6 and Ti-6Al-4V. TMC consolidated by SPS had tensile strengths of 857 to 1679 MPa from room temperature to 800℃.

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This paper aims to find out the influence of composition on shape memory characteristic of Ti-Ni-Cu alloy fabricated by pulse-current pressure sintering method. In the case of Ti powder, the solution-treatment results in decreasing in relative density. On the other hand, in the case of TiH_2 powder, the solution-treatment results in increasing in relative density, but decreasing in tensile strength and elongation. The increase in Ni equivalent value made the transformation temperatures lower.

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FeAl matrix composites, containing Al_2O_3 or Fe_3AlC, have been prepared by mechanical alloying (MA) and consolidation using vacuum hot pressing (VHP). The dispersoids, and also matrix, have been formed during MA and consolidation process from elemental starting material, Fe, Al, C/mill scale powder. Powder mixture were milled to form matrix having the composition of Fe-40mol%Al and 10vol% fraction of precipitation. The present study examined the effects of precipitation on the structure and mechanical properties from ambient to 1273K. Micro-hardness of the FeAl, FeAl+Fe_3AlC and FeAl+Al_2O_3 composition showed HV440, HV524 and HV813, respectively. FeAl+Fe_3AlC composition compact showed 0.2% proof stress of about 1380MPa from ambient to 573K. This value is much higher than the large grained Fe-40mol%Al, about 300MPa.

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