Metal matrix Composites was fabricated by infiltration of AC8A molten aluminum alloy to FeCrSi metal fiber preform using gravity casting. On this process, pressure of molten alloy with 0.8MPa and one direction infiltration of molten alloy to preform lead to obtain fully infiltrated composites with 0% porosity. The high temperature tensile strength and fatigue strength of the composite between room temperature and 350℃ was estimated. The composites have excellent fatigue strength at higher temperature. Furthermore crack introduced by fatigue at high temperature propagate in matrix around metal fiber with necking of metal fiber.

抄録全体を表示

冷媒圧縮機の軸受性能を改善するためにカーボン軸受基材を研究し、黒鉛結晶化度,黒鉛異方比および溶浸金属を最適化した開発基材は、冷媒,冷凍機油中におけるトライボロジー特性が大巾に向上した。この基材は、軸受の機械損失や機械部の容積効率の改善がはかれ、冷媒圧縮機の高耐力,高性能化に寄与できる。

抄録全体を表示

One of the functionally graded material (FGM) fabrication methods is a centrifugal method, which is an application of the centrifugal casting technique. In the method, a centrifugal force applied to a homogeneous molten composite assists the formation of the desired gradation. The composition gradient is then achieved primarily by the difference in the centrifugal force produced by the difference in density between the molten metal and solid particles. The fabrication of the particle-dispersed FGMs made by the centrifugal method can be classified into two categories based on the liquidus temperature of the master alloy. One is a centrifugal solid-particle method, where the processing temperature is lower than the liquidus temperature of the master alloy, and the dispersed solid phase or particles in the master alloy are stable in a liquid matrix. If the liquidus temperature is lower than the processing temperature, a centrifugal force can be applied during the solidification both to the nucleated intermetallic compound and to the molten matrix. This method is named as a centrifugal in-situ method. In this article, the microstructures, composition gradients, formation mechanism in FGM fabricated by both the centrifugal solid particle and in-situ methods are presented.

抄録全体を表示

Aluminum is already applied for engine parts. It has been a light structural metal to save their energy and to enhance their mobility. Copper is also applied for heat sink of radiator ; it has been a high thermal conductive. If the copper-aluminum welding with light, high strength, sparkles and high thermal conductivity, that is expected to be developed, it can be applied for parts of a racing car fuel system to save its energy and to enhance its mobility with large heat sink. On the other hand, strengthening mechanism of fiber-reinforced metals has been studied. By using a duplex-coated carbon fiber felt, copper welding to aluminum is successfully developed. The carbon fiber junction device is a fiber-reinforced alloy and acts as a joining part of copper and aluminum. The carbon fiber reinforcement enhances the tensile strength and the deformation resistant stress at each strain in CFRA.

抄録全体を表示

This paper concerns a newly developed Fe-Mn-Si-Al shape memory alloy (SMA) with a high ductility. We investigated the shape memory effect and the ductility of Fe-30Mn-(6-x)Si-xAl (x=0, 1, 2 and 3, mass-%) alloys. For x=0, the composition is consistent with that of the well known SMA of Fe-30Mn-6Si, while, for x=2 and 3 the alloys are nothing else but so-called TWIP steels, which are reported to show high ductility as much as 70% and 90%, respectively. It was found that the shape memory effect of the alloy containing 1 mass-% Al was not so different from that of Fe-30Mn-6Si SMA. The alloy also exhibits a high ductility like TWIP steels (more than 50%).

抄録全体を表示

A fabrication method of a metallic closed cellular material containing ceramics has been developed. Ceramics particles and porous ceramics 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. These particles were also sintered by a spark plasma sintering method. Metallic closed cellular materials containing ceramics were then fabricated. The three points bending tests were carried out to measure the mechanical properties of these materials. The results showed that these metallic closed cellular materials were brittle and do not have long plateau region.

抄録全体を表示

This paper describes the evaluation of the metal core PZT fiber/aluminum composite piezoelectric characteristics. As the metal core PZT fiber is very fragile and easy to react with molten aluminum, general fabrication processes such as diffusion bonding and casting process are hard to apply. So, in this study, the interphase forming/bonding method was used to embed the metal core PZT fiber in aluminum plates. By measuring its polarization-electric field (P-E) hysteresis loop, piezoelectric property of the embedded metal core PZT fiber was confirmed. By measuring out-put voltage generated from the metal core PZT fiber/aluminum composite during an oscillation test, wave forms of the out-put voltage corresponded with that of displacement and it was found that the metal core PZT fiber/aluminum composite had displacement sensing ability.

抄録全体を表示

This paper describes development of an active material based on a fiber reinforced metal and evaluation of its thermal deformation characteristics. In this study, the effect of heat-treatment on the thermal deformation characteristics of a SiC fiber/Al active composite of which SiC fiber filaments were non-uniformly distributed in the aluminum matrix was examined. As the result, the curvature of the active composite at room temperature was increased with increasing heating temperature and maximized at 833K. The curvature of the active composite at room temperature after heat-treatment was increased with increasing fiber volume fraction in the experimental range. The shape of the active composite at room temperature after heat-treatment was reproducible after heat-treatment at 833K.

抄録全体を表示

Hard disk drives (HDD) have various applications such as notebook computers, personal video recorders and cell-phones. The demand for HDD with high packing density becomes strong year by year. High density recording of magnetic disk requires the low surface roughness and waviness. In this study, to improve surface roughness, surface waviness and grinding rate in precision grinding of aluminum alloy magnetic disk substrate, the grinding experiment was conducted by using a laboratory scale vertical-axis grinding machine. Two-step grinding of aluminum alloy substrate was carried out. Then, effects of grinding conditions and lubricant on the surface characteristics and the grinding rate were investigated.

抄録全体を表示

This paper reports combinatorial search of novel amorphous alloy for advanced optical element (such as aspheric glass lens with diffraction grating etc.) forming die. Required properties of the amorphous alloy are as follows ; (a) the amorphous alloy film can be fabricated thickness more than 50μm on blank die. (b) Even if die of the amorphous alloy forms on a glass in air, the alloy do not crystallize and oxidize, and don't adhere to the glass. (c) Ultra-precision machining (surface roughness under 30nm Rmax) by single-point diamond machining (SPDM) is applicable to the alloy. (d) The fracture strength is more than 0.6GPa at least. To search the novel amorphous alloy, we employ combinatorial arc plasma deposition (CAPD). Pt-Hf-Zr-Ni amorphous alloy was picked out from over 25,000 samples using CAPD. The alloy filled the request and it succeeded in fabricating an advanced optical element forming die by SPDM.

抄録全体を表示

Miniature parts are needed largely due to the development of mobile phones, PCs and medical products. As a first step of a research of micro/meso-scale form rolling, the equipment is designed and manufactured. For characterizing the deformation during forming grooves on micro pins, two directional mark-off lines on the surface of pins were used. The change in the diameter, displacement in axial direction and twisting at circumferential direction is measured from the experiments.

抄録全体を表示

The more miniaturization is demanded from electronic parts as microelectronics develops, and the electric wire that composes them is thinner. However, there is a difficulty to connect electric wire and the terminal, because thin electric wire is breakable and melting easily. In these cases, such a joining method is effective as the plastic deformation is used and wrapped about the joint part on the terminal side by giving neither the transform nor heating such an electric wire, and to call this micro joining technology based on a new conception the micro mechanical joining method. In this paper, it was found that micro mechanical joining can fix the electric wire by plastic deformation experiment and FEM analysis.

抄録全体を表示

The purpose of this research work is to produce micro part reinforced with unidirectional whiskers by laser photolithography. Electric field is applied by probes in limited area, and the axes of whiskers in liquid photopolymer are aligned along the direction of the electric field. An electric field-applying device was developed. Whiskers can be aligned using the apparatus. The alignment of the whiskers depends on the permittivity and the viscosity of liquid photopolymer. The values are measured in this paper.

抄録全体を表示

We have developed a fine laser processing equipment with high accuracy positioning over the wide processing area. Galvanometer scanners and scanning lens made it possible to move the laser spots faster than mechanical stages did. So far this equipment had a somewhat large field curvature which adversely affected positioning accuracy over the wide scanning area. So we examined an influence of the beam expander lens on the field curvature by both optical analysis and experiments. In the experiment, stainless plates of 1mm in thickness were processed with this laser processing equipment across the wide processing area of 100mm by 100mm. The sizes of the process marks on the stainless plates were measured to evaluate the process performance of this equipment. As a result the sizes of the process marks were kept constant such as 30μm in diameter and 6μm in depth despite of the wide processing area.

抄録全体を表示

Casting products shrink due to the decrease of volume through solidification process in mushy state and the following cooling process in solid. In the report thermal stress caused by shrinkage in the cooling process is investigated using FEM computer simulation. It makes it clear that in case of the die casting, metal mold restricts deformation of product. The thermal stress becomes larger as cooling time longer until opening of the die set. It sometimes exceeds yield stress and plastic deformation remains after the end of cooling process.

抄録全体を表示

It is necessary to reduce the weight of an automobile body for an environment. Aluminum alloy parts are adopted instead of steel parts to reduce the weight. A6061 is more economy than A6016 and A6022 used for an automobile at present. This study used A6061 instead of A6016 and A6022. Process of roll casting has several advantages, including rapid solidification and low running cost. Furthermore, recycled aluminum was economy. This study examined A6061+0.2%Fe as model of recycled aluminum alloy. Roll casting of A6061 and A6061+0.2%Fe were tried using an unequal diameter twin roll caster. The casting speed was 30m/min. Thickness of strips were 4.8mm of A6061 and 4.6mm of A6061+0.2%Fe. The strips were rolled down to 1.0mm by cold rolling. T4 heat treated strips was operated with deep drawing and 2.0 of LDR value could be attained. As a result, this process prevented deterioration of a mechanical property.

抄録全体を表示

This paper describes the tensile properties of magnesium alloy strip produced by melt drag process. Melt drag process is the one of the single roll strip casting process. The thickness of the produced strip at roll speed 5m/min is about 4mm and the width is 60mm. The microstructure of the as-cast AZ31 strip is equiaxed structure and the average crystal grain size is about 80μm. Tensile test at room temperature was applied to examine the mechanical properties of the strip. Tensile strength is 142MPa and the elongation is 10.4% without anisotropy. The n-value is 0.37 and the r-value is 0.88. XRD pattern and (0002) pole figure indicated that the texture of the produced strip had large difference comparing to conventional rolling sheet. These differences may be caused by the randomized texture.

抄録全体を表示

Braze Pressure Welding (BPW) with high frequency induction heating is a newly developed pressure welding technique using brazing filler as interlayer metals for welding the general steel pipes for pipe arrangement in buildings. In this report, stainless steel pipes were joined by BPW with some kinds of interlayer metals, and the joint of the pipes made by BPW were evaluated by microscopy, element profiles and tensile strength of the joints in order to determine the suitable interlayer metal for BPW of stainless steel pipes. As the result of this research, the BPW joint using BNi-2 as interlayer metal was stronger with less melting of base metal than that of the BNi-5. A newly developed Fe-base interlayer metal was also suitable for BPW of stainless steel pipes.

抄録全体を表示

In order to investigate the reason why the brazing of dissimilar metals between aluminum alloys and stainless steel in the air, the brazing of various aluminum alloys to stainless steel were carried out using Al-Si brazing filler and the behavior of brazed interface was examined. As the result, the cause to make the brazing difficult is shown that the brazing filler is rapidly solidified isothermally due to the invasion of Zn into the brazing area from the flux, before the wetting of the brazing filler to stainless steel. Based on these phenomena, the two types of new joining method that brazing could be made were suggested and the practical applicability was tried.

抄録全体を表示

This study deals with a theory to estimate back bead width of a molten pool using information of molten pool shape and oscillation in automatic Tig welding. The natural frequency of a molten pool is detected using an arc sensor and the back bead width is estimated from bead width and a natural frequency of the molten pool. The molten pool vibration is analysed as a general dynamics vibration phenomenon in this study. As a result of experiments, it was verified that the proposed method is effective for estimating the back bead width.

抄録全体を表示

An intelligent welding robot system with visual sensors is developed in order to realize automatic welding of thin steel plates including automatic seam tracking and automatic control of welding conditions. In particular, control of a back bead width is crucial in thin plate welding, which requires the information on the back bead. However, it is difficult to observe the back bead directly, since sensors, such as a CCD camera, cannot be placed beneath the work in practical applications. Conventionally, the back bead width for a given geometry of a molten pool is estimated according to a database obtained from experiments, which was time and cost consuming. In this work, a welding simulation based on the heat conduction equation was performed to estimate the back bead width. Then a penetration control system using the simulation and visual monitoring of molten pool is constructed, and the effectiveness is confirmed by welding control experiments.

抄録全体を表示

TIG arc welding is widely used for welding aluminum alloys. However, for welding thin aluminum pipe, it is important to control welding parameters to produce uniform welding bead. This research studies the intelligent welding process of aluminum alloy pipe 6063S-T5 with the AC welding machine. The system uses image processing algorithm for visual sensing and neural network model for modifying welding speed. From the experimental results it shows that the image processing algorithm worked well and provides the input for neural network control. The result of experiment with control shows that the back bead width is in the range of 5±1mm with the standard deviation of 0.53mm.

抄録全体を表示

Aluminum is superior in lightness, corrosion resistance, a strength characteristic, property to being processed in comparison with other metal. In addition, I am used as a use of various fields by adding various addition elements, and in late years the consumption is a rise course as metal helping resource saving/energy saving. This article used 2107 sheet aluminum alloy which I put GTA welding, plasma welding, YAG laser welding, disk laser welding for and performed a tension test, drop test. And I weighed data 2017 which I demanded against a basic material and each welding method and clarified a mechanical property and a shock characteristic of a welding coupling. In addition, welding was stable by stack welding and used filler A5356-BY which there was for welding room because it was not possible. In addition, I matched the strength characteristic that I put a filler in and examined.

抄録全体を表示

Gold particles of 60-80μm in diameter are welded to a gold substrate of 300μm in thickness by applying high voltages of 10kV to a tungsten needle-like probe which is in contact with the particle. The joint is strengthened by an electric discharge from the probe positioned 20μm above the particle. After welding, the joint was fractured by tensile loading, and the fractured load is measured by a strain gauge. The welding area is estimated from the observation by an SEM and a laser microscope after the joint is fractured. The fracture load is plotted against the welding area, and effects of several factors on the strengthening are discussed. The fracture load increased 6 times or more by flowing N_2 gas during non-contact welding. While the effect of preheating during the non-contact welding is not clear. The fracture stress is greatly scattered, because of the estimation error of welding area and distribution of stress concentration factor.

抄録全体を表示

In this research, in order to extend the scope of the friction stir welding, the junction experiment of pure copper was conducted. It succeeded in joining by optimization of the welding conditions such as tool rotation speed or welding speed. As a result of measuring junction temperature, value lower than fusing point of the copper chosen as material was shown, and it became clear that it is junction of a solid phase state. Furthermore, in the mechanical property, tensile strength higher than TIG welding which is a method of joining conventional copper was shown. However, the hardness of the joined portion was low. FPB treatment was performed for improvement in the reliability of junction material. The hardness test and the tension test were carried out. As a result, the mechanical property was improved by performing FPB treatment.

抄録全体を表示

This paper describes high-quality welding of magnesium alloy. At first welding defects were restrained by pulse wave pattern control. Next, the defects were restrained by irradiating simultaneously two beams. The pulse wave YAG laser beam and continuous wave YAG laser beam were combined to irradiate the magnesium alloy. One factor of porosity and crack formations was the remain of metal plasma inside the molten zone by steep collapse of a keyhole. Therefore, the welding defects occurred easily only in the pulse YAG laser welding. Then, the keyhole was formed by the pulse wave YAG laser beam, and the CW laser was combined to prevent rapid cooling. As a result, the cracks and the porosities structure were completely restrained, and the melt diameter and the penetration depth increased.

抄録全体を表示

Laser cladding of magnesium alloy was studied in order to develop a surface treatment method which produce modified region with excellent fatigue property. Single beam, cross twin beam and tandem twin beam was applied. Si powder was used as a mixing powder to expect formation of Mg_2Si in the weld pool. The powder was stirred well in case of tandem beam. Weld pool molten by the forward beam might be strongly stirred by the followed beam according to the result of FEM analysis.

抄録全体を表示

This paper deals with development of a new method for producing profile grinding wheel. At first, the desired shape is made of metal that is machined easily. Next, powder material is spread on a surface of the metal. And the surface is scanned by a laser beam and then a ceramic layer is produced on the surface of the metal by the chemical reaction between the powder material and metal material. The produced ceramic layer is used as grinding wheel. The powder material is boron and the metal material is titanium in this experiment. The components of the layer are examined by X-ray diffraction and titanium boride is detected in the layer.

抄録全体を表示

Die and punch for cold forging are broken or damaged in a short time due to specific high load which is cyclic and higher than fatigue strength. In this paper, the fracture process is analyzed by examing the stress distribution through total forging process using FEM calculation and observing the fracture surface. And the method to avoid total damage and improve the life of die is proposed. The main results are as follow ; (1) The main cause is fatigue for the tensile stress. And the direction is across the fracture surface. (2) Load-stroke curve is similar to the change of maximum principle stress. (3) It is possible to anticipate the causes and process of fracture by way FEM simulation and observation of the fracture surface.

抄録全体を表示

Forgeability of magnesium alloy AZ31B (Mg-3%Al-1%Zn) is investigated by upsettability test on AC servo-controlled press at elevated temperature. The slide speed and motion of AC servo-controlled press are controlled by servo motor. When the AZ31B billet is compressed with decelerating motion of the punch at the temperature of 200℃, the ductility is improved and it is possible to compress the billet without cracking up to the reduction in height of 70%.

抄録全体を表示

In press forming, rubber die is a convenient tool to deform thin plate to various shapes. However, the surface pressure distribution is varied by punch shape and deformation process. When the surface pressure can be controlled, the usage of rubber die will be applied to various forming. In this study, the effects of rubber and retainer shapes are investigated by FEM analysis. As a result of the analysis, it is realized that the combination of cylindrical rabber is effective in uniform pressure distribution.

抄録全体を表示

Upsetting of an aluminum alloy A6061-T6 is performed to investigate the effect of surface flaw on fracture. A prediction of surface cracking by means of three fracture criteria is attempted. A parameter for prediction of orientation of crack is proposed. The longitudinal flaw leads to earlier surface cracking, while circumferential flaw does not affect surface cracking. Ohyane's criterion, which is based on void growth under triaxial stress state, can well predict the surface cracking by using the stress and strain at flaw root by FEM. The crack orientations predicted by the parameter proposed are in good agreement with the experimental ones.

抄録全体を表示

The microstructural evolution of a Ni-30Fe alloy during hot deformation have been investigated to clarify the effect of shear deformation for refining crystal grains. The alloy was compressed by 50% or 75% in thickness at a strain rate of 1/s in a single pass at 1023K using a hot compression simulator. An explicit FE-analysis was carried out to evaluate the inhomogeneous strain distribution introduced in the specimens by hot compression simulator. The results are shown that the shear deformation is effective for refining crystal grains.

抄録全体を表示

A new flexible roll bending system that can bend a plate into various shapes with curved and torsional surfaces was developed. It consists two pair of feeding rolls and a pair of forming rolls. The effects of relative position and the angle of the forming rolls on the shape of deformed specimen were examined. As a result of the experiments, the position and angle affected the feeding direction curvature and the torsion rate of the shape of specimen respectively. Therefore, it is necessary to control those two parameters simultaneously in order to form products that have various curvature and torsion.

抄録全体を表示

The flexible roll bending system that was described in previous paper can twist and bend plate by movement of forming rolls. It can provide constant curvature and torsion rate to the plate by feeding with keeping proper roll position. The deformed specimens bent by this system were described radius and pitch of spiral shape as a surface of cylinder. A diagram of relationship between forming roll condition and specimen shape was obtained from torsion rate and curvature calculated from deformed specimen. As a result of forming, the spiral shape after forming was estimated with the diagram.

抄録全体を表示

Temper rolling which is the final process in cold rolling is important to determine product quality such as mechanical properties and surface qualities. Transcription mechanism of surface roughness from a roll to a sheet was not been made clear, and in practical operation, surface texture is controlled on the basis of experimental data. In this study, laboratory scale temper rolling experiments using three kinds of roll texture and three kinds of lubrication were conducted for low carbon steel sheet and effects of tribological conditions on transcription of surface roughness from roll to sheet were investigated.

抄録全体を表示

Laser peening is an emerging surface technology to prevent stress corrosion cracking (SCC) and enhance fatigue properties by imparting compressive residual stress. The authors confirmed the residual stress state in the laser-irradiated top surface with specially developed X-ray diffraction technique controlling the X-ray penetration depth constant during a series of exposures with different Ψ angles. The results showed that the residual stress in the top surface after laser peening was compressive. The absolute value was somewhat decreased by thermal loading, however, the overall distribution was still stable up to 673K for SUS304.

抄録全体を表示

The authors have applied laser peening to an austenitic stainless steel SUS304 and a cast aluminum alloy AC4CH to investigate the effect on the high-cycle fatigue properties. Rotating-bending fatigue testing was performed for samples with and without laser peening. The results showed that the fatigue life of laser-peened material was significantly prolonged compared to unpeened material. Replication technique and micro tomography (μCT) with highly brilliant X-ray of SPring-8 were applied to precisely evaluate the effect prohibiting pre-crack from propagating in laser-peened material. The three dimensional (3D) image of fatigue cracks was clearly reconstructed by micro tomographic technique with a phase contrast effect of coherent X-ray of SPring-8.

抄録全体を表示

Welded sheets were V bent by laser forming. In bending welded sheets, changing of microstructure at heat affected zone is appeared, and bending accuracy is low. It is, however, easy to control the bending angle precisely by laser forming. The bending angle of welded and not welded sheets increased, when laser power increased from 40 to 55W. But bending angle of welded sheets was smaller than that of not welded sheets. And bending angle of welded sheets decreased as the measurement position approached the center of welded position. The bending angle was affected by increasing the hardness of the welded zone.

抄録全体を表示

With the development of advanced medical treatment, the demand for fine tubes in the medical field is now very high. The technology employed must enable the production of tubes with various features, such as the following four ; small size, high quality, high functionality, and low processing cost. A method of manufacturing a high-quality surface tube was examined using shape memory ally tube a seamless stainless-steel tube. We perfume draw the tubes on mandrel using a fluid. We examined whether it would possible to manufacture high-quality fine tubes. Whose diameter is less than 1mm.

抄録全体を表示

Floating-expanding-plug bending is a method to bend a pipe precisely. This method is characterized by pipe expanding and floating plug movement, which were functionally acting each other to bending, reducing force and producing good cross-sectional profile. This method was mainly used for thin walled pipes. The experiment on bending thick walled pipes were carried out in order to realize influence of expand ratio and effect of roll displacement on curvature of thick pipe, and the appropriate bending conditions were obtained.

抄録全体を表示

Diamond is the hardest material, therefore, diamond is used as tools for ultra-precision machining. For practical use, diamond must be machined into the desired shape. Generally diamond is machined by polishing disc with diamond powder, but this method takes long time and is limited of plane form. By the way, when steel is cut by a diamond tool, it is well known that a diamond tool is worn severely. The purpose of this research work is to machine a diamond by utilizing this wear. The removal rate of the diamond is investigated in this paper.

抄録全体を表示

Large die castings with shell structure for automobile have a thick gate and many runners just after casting which have to be removed using knife-edge cutters because the method by applying bending force to them has some possibility to deform the part of product. In this paper, the cutting method of die castings by knife-edge cutter is examined, mainly focused on the quality of cutting surface and the cutting force through using cutters with several cutting-edge shapes. As cutting condition has a strong effect on the separating process aluminum alloy die castings, the optimum condition should be analyzed in detail experimentally.

抄録全体を表示

Teeth of a living thing have the optimum shape for major food under conditions of its environment, ecology and the object of its teeth. A shark has triangular teeth with serrated edge because it eats large fish and mammals. In this paper, superiority of the teeth was verified by cutting test using serrated edge which imitate teeth of shark.

抄録全体を表示

An anti-plane shear crack in a plate with finite thickness is analyzed by the continuously distributed dislocations model using the elastic stress field of a screw dislocation in a thin plate and the stress intensity factors are calculated. It is shown that the Mode III stress intensity factor becomes larger as the thickness becomes smaller to the crack length. The signs of the Mode II stress intensity factor on the top and the bottom plane surfaces are opposite, which indicates that a crack is inclined to the thickness direction.

抄録全体を表示

In order to measure fracture toughness from small aluminum alloy components, fracture properties of rolled aluminum alloy A6061-T651 and casting alloy AC4CH-F are investigated using several small-size specimens. It is shown that fracture toughness of A6061-T651 is influenced by specimen thickness. Therefore, it is important to notice start point of stable fracture and to miniaturize a specimen size W and thickness B in similar shape. Fracture toughness of AC4CH-F isn't influenced by specimen thickness to some extent.

抄録全体を表示

It is quite important to understand the mechanical properties of micro materials for further development of micro-electromechanical system, for instance. Advanced testing method suitable for small-size specimens have been necessary to evaluate the mechanical properties of the small-size material such as a thin film, because these properties differ from those of bulk materials. In this study, in-situ micro material testing device combined with a scanning electron microscope developed for that purpose is reported. The idea of the testing device is in usage of multi-layered piezoelectric actuator. This actuator brings realization of a quite small-size testing device, and thus we could combine the testing device with a scanning electron microscope for observing continuously micro damage in thin film such as micro crack initiation and propagation. In this report, we will show outline of developed testing device with the multi-layered piezoelectric actuator and interested mechanical properties at a high-temperature condition, fatigue lives and fracture toughness for Type 304 stainless steel thin film.

抄録全体を表示