-
Shunsuke SAKAMOTO, Akira MATSUO, Koichi GODA, Junji OHGI
Article type: Article
Session ID: 3003
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The purpose of this study is to develop a green composite with a high strength and stiffness, using long bamboo fibers, in order to apply biomass resources for practical use. Two kinds of biodegradable resins were used as a matrix of the composite, and hot-pressed with the reinforcement. In addition, bamboo fibers were dyed to create a good interfacial bonding between the fiber and matrix, and compared with untreated fiber reinforcement. In this study, furthermore, the effect of water content included in the composite on the mechanical properties of the composite was explored. The results show that the composites indicate a relatively large tensile strength, comparable to ramie fiber-or Manila hemp fiber-reinforced green composites. On the other hand, dyeing for the fibers and water content in the composite did not significantly affect their mechanical properties.
View full abstract
-
Jun-ichi OZAKI, Takehiro MAEDA, Tomonori TAKAHASHI, Ken-ichi MANABE
Article type: Article
Session ID: 3005
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Aloofah fiber reinforced lignin composite was fabricated to develop a new green composite material. The composite was fabricated using hot pressing method. As the fabrication conditions of the composite, two molding pressure conditions of 16.7MPa and 41.7MPa were chosen for the fabrication at a temperature of 150℃. Bending test was carried out to evaluate the mechanical property. Bending modulus of the green composite increases as the volume fraction of loofah fiber decreases. As a result, it is seen that the bendability of composite plate is improved.
View full abstract
-
Hitoshi TAKAGI, Shuhei KAKO, Koji KUSANO, Akiharu OUSAKA
Article type: Article
Session ID: 3006
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Bamboo fiber-reinforced "green" composites were fabricated by using a conventional hot pressing method. Their insulating properties were evaluated by the value of thermal conductivity, which was measured using a hot wire method. It was demonstrated that thermal conductivity of bamboo fiber reinforced "green" composites is smaller than that of conventional GFRP (glass fiber reinforced plastics) and CFRP (carbon fiber reinforced plastics). The thermal conductivity of "green" composites was significantly influenced by their density as observed in woods.
View full abstract
-
Takafumi DOI, Takeshi KAJI, Koichi GODA, Junji OHGI
Article type: Article
Session ID: 3007
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The purpose of this study is to improve the strength and stiffness of natural fiber green composites through mechanical treatment, and to equalize the mechanical properties of the composites with those of glass fiber composites. Cyclic tensile stress at 70% level of their initial strengths was applied twenty times for single ramie fibers and ramie fiber green composites. The tensile strengths and Young's moduli of the fibers and composites were improved 50 to 60% higher than their initial values. This effect is also exhibited for mercerized ramie fibers and mercerized ramie fiber green composites. On the other hand, a large fracture strain, the merit of mercerization, was reduced because of occurrence of plastic strain in the mercerized fibers. Young's modulus of the improved composites is comparable to the level of glass fiber composites.
View full abstract
-
Hiroki NOMURA, Rie NAKAMURA, Koichi GODA, Junji OHGI
Article type: Article
Session ID: 3008
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In recent years, research and development of materials using biomass sources is much expected to construct sustainable society. The so-called green composite (GC) consisting of natural fibers and biodegradable resin, is one of the most promising materials in biomass ones. The purpose of this study is thus to develop a textile GC material using ramie woven fabrics, and clarify its deformation behavior and mechanical properties. Generally, it is said that deformation behavior of textiles is determined by fabric density, crimp angle of yarns, yarn twisting and so on. Therefore, this study focuses on how these parameters affect the deformation behaviors and mechanical properties. The results show that yarns tension occurring in the fabric during weaving affects the tensile strength and Young's modulus, while the fabric density also affects their mechanical properties.
View full abstract
-
Mitsugu TODO, Ayako HARADA, Kazuo ARAKAWA
Article type: Article
Session ID: 3009
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Polymer blends of PLLA and PBSC with different blend ratio were developed, and for each material, a fracture property, J_<Imax>, was measured using SENB specimen. It was found that J_<Imax> increased with increase of PBSC content up to 10wt% of PBSC. It was also shown that PLLA/PBSC has better fracture property than neat PLLA and PLLA/PCL blend. FE-SEM observation of phase morphology showed that the miscibility between PLLA and PBSC is better than PLLA and PCL. FE-SEM observation of fracture surface also exhibited that ductile deformation is dramatically increased by PBSC blending, resulting in the improvement of the fracture property.
View full abstract
-
Tetsuo TAKAYAMA, Mitsugu TODO, Kazuo ARAKAWA
Article type: Article
Session ID: 3010
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
LTI was added to blend of PLA and PCL to improve the immiscibility between the two biodegradable polymers. Fracture properties of PLA/PCL and PLA/PCL/LTI were evaluated and compared to assess the effect of LTI on the fracture behavior. The critical energy release rate at crack initiation, J_<in>, was improved effectively due to LTI addition. Fracture surfaces were also examined using SEM to characterize the fracture mechanism. It was confirmed that the size of PCL spherulites became smaller by adding LTI, and hence void formation was inhibited, resulting in the improvement of the fracture property.
View full abstract
-
Satoshi TOMONAGA, Takanobu OIKE, Satoshi SOMIYA
Article type: Article
Session ID: 3011
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Green composites are expected as alternative materials of multipurpose plastics. As the runup to green composites, it is necessary to explain various properties of matrix. This study reported the effect of water Environment on mechanical properties of matrix (PLA). As a result, PLA absorbed water in water environment and its mechanical properties decreased with increase of water absorption. On occasions When PLA was in water environment at high temperature and for a long time, its mechanical properties decreased with development of degradation. It is recognized, by observation of specimens and decreasing of its weight, that this decreasing of mechanical properties are caused by corrosion layer weaken by elution. And It is recognized by FT-IR analysis that Corrosive layer was caused by ester hydrolysis.
View full abstract
-
Takanori SUGIMOTO, Yasutoshi SASAKI, Machiko TAKAHASHI
Article type: Article
Session ID: 3012
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Two-stage fatigue test of structural plywood under panel shear load was conducted. Pulsating load with a triangular waveform and a loading frequency of 0.5Hz was applied along the length of specimens. Minimum stress applied was zero, and maximum stress was once changed during the fatigue test. Four patterns for changing the maximum stress were determined in High-Low and Low-High sequence, respectively. Stress-strain relationships were measured throughout the fatigue test. Fatigue life of plywood specimen obtained in two-stage fatigue did not follow the Palmgren-Miner rule. On the analyses of strain energy, the change of applied maximum stress induced the corresponding change of strain energy in a loading cycle. Relationships between cumulative strain energy at failure and fatigue life in both High-Low and Low-High sequences were almost equivalent to that obtained under constant fatigue loading. These results indicate that the plywood specimen fractures irrespective of loading history when its cumulative strain energy reaches the failure criterion obtained under constant fatigue loading.
View full abstract
-
Kentaro Kozuki, Masaki Omiya, Kikuo Kishimoto, Hirotsugu Inoue
Article type: Article
Session ID: 3013
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The aim of this paper is to evaluate the cyclic interfacial strength by cyclic nanoindentation tests. The specimen used in this study is PET substrate/ITO coatings layered specimen. In this study mono cycle nanoindentation test and 10 cycle nanoindentation were conducted on each load, and these results were compared. From indentation load and displacement curves, we classified those results into 3 types (A-C). These three types relate the maximum loads. After the cyclic indentation, we observed the surface profile by the function of atomic force microscope. On Type A, the deviations were observed on the edge on indentations. On Type B, some elongates were observed in the indentations. In addition the number of elongates increased by repeating nanoindentation. These phenomena can be explained by simple models. In this study, two types of fracture modes are proposed. They are "subsidiary fracture mode" and "buckling mode". From the deviation of indentation load and displacement curve, we proposed the method to estimate the energy used for thin film delamination and the interfacial strength was evaluated. The results are good agreement with the interfacial strength evaluated by peel test.
View full abstract
-
Tomohisa TSURUMI, Masao KOHZAKI
Article type: Article
Session ID: 3014
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The purpose of this work is to improve adhesive strength of Ti doped DLC films by heat treatment in vacuum. The films have been prepared on silicon substrates by DC magnetron sputtering using C and Ti target in Ar plasma. The amount of Ti has been changed with the input electric power to Ti target from 0 to 200W. The adhesive strength of DLC film and Ti doped DLC films were measured by scratch tests. The adhesive strength of DLC film was decreased by the vacuum heating. On the other hand, that of the Ti doped DLC films was improved irrespective of the deposition conditions. Especially, the heat treatment was most effective for the film containing large amount of Ti to improve the adhesive strength, and that became larger above two times after the heat treatment.
View full abstract
-
Yuya SUGIURA, Masao KOHZAKI
Article type: Article
Session ID: 3015
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this research, we formed DLC films with copper interlayer by DC magnetron sputtering method. To improve the adhesive strength of the films to steel substrate, Cu contents were varied gradually to from the mixing layer around the interface between Cu and DLC. DLC films were peeled off from SUJ2 substrate just after the deposition. On the other hand, DLC films with the interlayer or the mixing layer were succeeded to prepare on SUJ2 substrate at 100℃. Furthermore, Rockwell indentation study showed that the adhesive strength of the DLC films with the mixing layer was higher than that of the DLC films with the interlayer. Therefore, to form the mixing layer is thought to be effective for improving the adhesion of the DLC films. However, the adhesive strength decreased with increasing the substrate temperature even on the DLC films with the mixing layer. This is mainly due to the differences of thermal conductivity and thermal expansion coefficient between Cu and C in the DLC films.
View full abstract
-
Marii TOMIYAMA, Masao KOHZAKI
Article type: Article
Session ID: 3016
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Al-B-C thin films have been prepared on Si substrates by DC magnetron sputtering at 350℃. The compositions of the films were varied with using an Al-C composite target, AlB_2 target and B_4C target with Ar gas and/or CH_4 gas introducing. In this experiment, high temperature oxidation was investigated with heating the films at 500℃and 800℃ in air. Friction and wear properties were also investigated. Al-B-C thin films containing 24at% Al deposited using AlB_2 target and B_4C target with Ar gas showed high performance after heating. The films containing 34at% C and having bonding of B and C deposited using AlB_2 target and B_4C target with Ar gas and CH_4 gas were oxidized easily at 800℃ because of losing C. It suggests that the increase in content of Al is effective against oxidation of the films and obtaining crystals of B_4C in the films will improve oxidation resistance of Al-B-C thin films. However, the films containing 34at% C showed lower friction coefficient and higher wear resistance than the films containing 24at% Al.
View full abstract
-
Akira AZUSHIMA, Yasuo TANNO, THE VINH NGUYEN, Hiroyuki HATTORI
Article type: Article
Session ID: 3017
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In order to decrease friction loss of mechanical parts, we have researched the tribological properties of TiN coatings with the preferred orientation grains deposited by Arc Ion Plating. It is possible to control the preferred orientation of TiN thin film due to change the substrate bias voltage. In ball-on-disc friction test, TiN coatings with (111) preferred orientation reveal lower coefficient of friction (about 0.2) than those with (200) preferred orientation. Furthermore, we have examined to improve the frictional properties of TiN coatings by combining the grain orientation control and the addition of third element in AIP process. The coefficient of friction for TiN coatings with (111) preferred orientation added Boron as third element (the orientation controlled Ti-N-B coatings) is measured by the ball-on-disc friction test. In various sliding conditions, it is found that the orientation controlled Ti-N-B coatings are able to maintain low coefficient of friction (about 0.2) in comparison with TiN coatings.
View full abstract
-
Kazuaki NISHIYABU, Koji KAMEO, Klaus FRIEDRICH, Toshio TANIMOTO, Shige ...
Article type: Article
Session ID: 3018
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The wear resistance of stainless steel parts, which were fabricated by a metal injection molding (MIM) process, was studied under self-mating, dry sliding conditions, using a pin-on-disk type wear configuration. The materials used were an austenitic stainless steel 316L (of MIM and wrought steel), a precipitated stainless steel 17-4PH (of MIM and wrought steel), and a widely used ball-bearing steel (DIN 100Cr6). Two surface conditions, i.e. as sintered and as polished, were considered in the wear tests of the MIM samples. In summary, the wear resistance of 316L was lower than 17-4PH, and the latter was almost the same as 100Cr6. Further, the wrought materials showed a better wear resistance than the MIM materials. The mechanisms responsible for these tendencies were discussed by means of microscopical observations and chemical inspections of the worn surfaces and the microstructures of the samples.
View full abstract
-
Takamasa MIYAMOTO, Toshihiko AMANO, Koji TAKAHASHI, Kotoji ANDO, Fumio ...
Article type: Article
Session ID: 3019
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Kazunori INADA, Kentaro FUJII, Takahiro HAMAO, Kazuhiro MORINO
Article type: Article
Session ID: 3020
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Aluminun alloy has been used to trim weight in recent years. This tend will continue in the future. However, aluminum alloy has a week point that its hardness is lower than that of iron-based metals. Also, the surface is easily damaged in comparison with iron-based metals. In this study, a modified layer was formed on the surface of various aluminum alloys by coating it with powdered SUS316 first and then by irradiating a YAG laser beam. As a result, we got the thick modified layer with high hardness on the some kinds of aluminum alloys.
View full abstract
-
MING Yang, Atsushi OSAKO
Article type: Article
Session ID: 3021
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Recently, micro plastic forming is attracted a lot of attention because of their advantage for mass productive and production efficiency. The technologies of creating the micro die occupy an important place in micro plastic forming. It is difficult to apply traditional method of surface process to micro die. So, in this paper, ion beam irradiation was used as surface process for micro die (round shape punch) made of carbide or high speed steel and surface roughness and surface properties (Young's modulus and hardness) were estimated. Irradiation time and accelerating voltage, ion species was set up as parameter in ion beam irradiation. In all conditions surface roughness was reduced. In long irradiation time and high accelerating voltage surface properties was improved. After time durability that is influenced by ion beam irradiation will be estimated with test used actual equipment.
View full abstract
-
Ahmed Bucheeri, Sergey Zherebtsov, Katsuhiro Maekawa, Masatoshi Futaka ...
Article type: Article
Session ID: 3022
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The effect of the in-situ substrate temperature on the residual stress in laser alloyed layer has been investigated. Type 316 stainless steel was laser alloyed with Al-Si powder to achieve a surface layer with high performance. The temperature of the substrate during laser treatment was maintained in range of 20-300℃. The microhardness of the laser alloyed layer was found to be about 2.5 times higher than that of the untreated substrate. Residual stress in the laser alloyed layer was measured by the sin2Ψ technique. Residual stress was found to be decreased with increasing substrate temperature. Increase in the temperature from 20 to 300℃decreases residual stress by 60%, changing the stress state from tension to compression.
View full abstract
-
Liqun RUAN, Kyoichi Oda, Yasuhiro Imamura, Yasuo Marumo, Satoshi Daiju
Article type: Article
Session ID: 3023
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Processing temperature and processing speed have an influence on the friction interface in the plastic deformation process. In this study, with the localized rod drawing method, tribology characteristic of the magnesium alloy was investigated by using various wavy dies which can induce various arbitrary surface expansions. Under different processing temperatures and processing speeds, the coefficient of friction and the galling weight of the dies were evaluated.
View full abstract
-
Yasutomo UETSUJI, Tomoyuki OHNISHI, Sadaomi KUMAZAWA, Kazuyoshi TSUCHI ...
Article type: Article
Session ID: 3301
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Bio-compatible piezoelectric materials are becoming important for actuators and sensors in medical devices, that is Bio-MEMS such as health monitoring systems and drag delivery systems. In this study, we focused on perovskite-type compounds ABX_3, and searched systematically new bio-compatible and lead-free piezoelectric materials by first principles calculation. Especially, halogen and chalcogen atoms were widely applied to X. And then, a crystal system distinction based on Pauling's rule was proposed to find the compounds with good piezoelectric response. The validity of crystal system distinction was proved by application to existing compounds and first principles evaluation. The obtained new compounds were distinguished among cubic, tetragonal and orthotropic structures, and their stable crystal structures were evaluated by first principles calculation.
View full abstract
-
Kenjirou MAEDA, Kazuyoshi TSUCHIYA, Toshiyuki UENOYA, Yasutomo UETSUJI ...
Article type: Article
Session ID: 3302
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In this study, an sputtering technique of a newly designed biocompatible piezoelectric material MgSiO_3 for Bio-MEMS actuator is developed, which has a tetragonal perovskite lattice structure. This crystal structure was designed by using numerical analyses, such as HSAB rule, the geometrical compatibility assessment, and the first principles DFT calculation. We sputtered MgSiO_3 film tetragonal MgSiO_3 perovskite crystal using sputtering method under which crystal grows epitaxially and lattice constant can be controlled. we found an optimum condition of, 1) a substrate temperature 2) a target ratio and 3) an annealing temperature, and confirmed an electric-field-induced strain of a newly sputtered MgSiO_3 film.
View full abstract
-
Achariya RAKNGARM, Yukio MIYASHITA, Yoshiharu MUTOH
Article type: Article
Session ID: 3303
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Electrochemical depositions of calcium phosphate thin film on commercial pure titanium and Ti-6Al-4V in an electrolyte, monocalcium phosphate monohydrate (MCPM) based aqueous solution, was carried out by the cathodic reaction. The substrates were etched in 20% by volume of HF for 10sec before electrolytic deposition process. The calcium phosphate thin film could be formed in negative regions at 3 to 5mA/cm^2. The film thickness was varied depend on its deposition time and current density. In addition, the uniformity of film depended on current density. The major phase appeared in the film were brushite co-existed with amorphous calcium phosphate (ACP). The Ca/P ratio from EDS analysis were 1.16, 1.38 for brushite and ACP. After soaking in revised-simulated body fluid (r-SBF) for 24h, the amorphous bone-like apatite (major phase) existed with β-TCP (minor phase). The Ca/P ratio of bone-like apatite was 1.67 which was equal to those of human bone.
View full abstract
-
Satoshi JINNINN, Hidetake YAMAMOTO, Kazuyoshi TSUCHIYA, Yasutomo UETSU ...
Article type: Article
Session ID: 3304
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The purpose of this study is to generate and characterize a titanium alloy microneedle, which can be equipped in Bio-MEM such as HMS (Health Monitoring System) for the blood sugar level measurement. One of the most important subject for the Bio-MEM is a microneedle with a inner diameter of 100μm and a outer one of 200μm, which mimics female mosquito's painless blood extraction mechanism. In this study, a microneedle generation was performed through 1) selection of a biocompahble material from titanium alloys by the cytotoxic assay, 2) RF magnetron sputter generating of the microtubes with a inner diameter of 100μm, a outer one of 200μm and a length of 4mm, and 3) evaluation of suction by the vacuum blood extraction tests. Consequently, the titanium microneedle obtained the flow rate of 6.2μl/sec.
View full abstract
-
Yutaka KAMEYAMA, Yutaka MATSUI, Jun KOMOTORI, Noriyuki HISAMORI
Article type: Article
Session ID: 3305
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
-
Takashi SAKAI, Naoto OKADA, Koki MORIKAWA, Kenji MARUSASA, Jun-ichi KO ...
Article type: Article
Session ID: 3306
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Metallic materials are known to produce refined crystal grains. This grain refinement realizes superior strength and recycling capabilities. Our mass-consumption society must reconsider the importance of reusing various items. Ferrous materials were refined by cold working. Springback degrees were examined using bending tests, and mechanical properties were assessed using tensile tests because the working properties of materials were known. Results proved that the springback degrees tend to increase according to an increase of the degree of cold-working. The crystal grain size decreased. Ferrous materials strength was improved, but ductility decreased.
View full abstract
-
Takashi SAKAI, Keisuke YOSHIDA, Kenji MARUSASA, Eiji Nakamachi
Article type: Article
Session ID: 3307
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A "Super metal" was produced by controlling the grain size for fine grains. This material has high strength and recycling properties. This study investigated the continuous ARB method to obtain fine-grained crystals from A1100 and C1020 specimens, which respectively showed maximum equivalent strains of 4.00 and 3.46 respectively. The relationships between several mechanical properties, crystallographic orientations, and inverse pole figures obtained from SEM-EBSP analyses were investigated experimentally and analytically. Results clearly showed the influence of crystallographic orientation on micro-bending properties.
View full abstract
-
Takashi SAKAI, Naoto OKADA, Keisuke YOSHIDA, Jun-ichi KOYAMA
Article type: Article
Session ID: 3308
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
To improve the material characteristics of single and polycrystals of pure aluminum, pure copper, SPCC, SS400, SUS316, and NFG steels, the respective relationships between crystallographic orientations and microstructures, and the bending and mechanical properties were examined. Several grain refinement procedures such as ARB and ECAP methods were performed to obtain an ultrafine-grained structure. Furthermore, some analytical results related to crystal direction maps, inverse pole figures, and textures were obtained from SEM-EBSP analyses. Numerical results from AITAS analyses were also investigated. Results showed that these grained metallic materials have peculiar springback characteristics with various bending angles.
View full abstract
-
Shoichi IMAYOSHI, Noriyuki HISAMORI, Yukito HAGIHARA
Article type: Article
Session ID: 3309
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The damage accumulation mechanism of Ti-6Al-4V alloy under simultaneous corrosion and fatigue was studied. Corrosion fatigue characteristics of the alloy were evaluated by using newly developed corrosion-fatigue system, with special attention to synergetic effects of corrosion and fatigue on repassivation behavior. Two types of corrosion fatigue tests, potentiostatic polarization test with fatigue damage and free corrosion potential measurement test with simulataneous application of fatigue were carried out. In corrosion fatigue test, the electric current density increased as the frequency of fatigue became higher. This is caused by surface corrosion reaction occurred with development of cracks. However, the number of cycle to failure did not change with the frequency of fatigue. Therefore, it was shown that fatigue does not influence the corrosion fatigue damage. It was also shown that titanium alloy was superior in corrosion resistance.
View full abstract
-
Satoshi NAKAMURA, Noriyuki HISAMORI, Yukito HAGIHARA, Atsushi SUGINO, ...
Article type: Article
Session ID: 3310
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Two types of notched specimen of Ti-6Al-4V simulated screw configuration were prepared and cyclic fatigue test was performed in air to study fatigue property of titanium screw. Effect of heat-treatment on fatigue strength was also investigated. As a result, the specimen having a smaller notch diameter showed higher fatigue strength (N_f=10^7) than that of larger one. This result indicates that fatigue strength of notched screw can be organized with its stress concentration factor. Heat-treatment improves tensile and fatigue strength, but, endurance ratio (fatigue strength/tensile strength) become lower compared as-received materials, which supports the idea that heat-treatment affected strongly to the tensile strength not to the fatigue properties.
View full abstract
-
Kazuto TANAKA, Masatoshi UCHIYAMA
Article type: Article
Session ID: 3311
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Ultra High Molecular Weight Polyethylene (UHMWPE) has been used for the bearing materials in joint arthroplasty owing to its superior mechanical properties and high chemical resistance. However, effects of gamma-irradiation and accelerated aging on the mechanical properties has not been revealed. In addition, although the addition of Vitamin-E to the gamma-irradiated UHMWPE has reported to prevent the fatigue crack propagation, the prevention mechanism has not been clarified yet. In order to understand the influence of gamma-irradiation, accelerated aging and Vitamin-E (α-Tocopherol) on the mechanical properties of UHMWPE, we carried out tensile test and fatigue test of UHMWPE fiber and fatigue crack growth tests of UHMWPE plates. For tensile test of fibers, the displacement at failure decreased by accelerated aging, but the decrease of displacement at failure was revealed by adding Vitamin-E. For fatigue test of fibers, virgin specimen was fractured at lower stress than tensile strength influenced by cyclic loading. Furthermore, the fatigue strength was lower for accelerated aging specimen than virgin one. For the fatigue crack growth behavior, addition of Vitamin-E reduced the decrease of ΔK_<th> by gamma-irradiation and accelerated aging.
View full abstract
-
Mototsugu TANAKA, Taiji ADACHI, Masaki HOJO
Article type: Article
Session ID: 3312
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In order to establish the principle to create smart composite materials, it's necessary to study from living bone tissue that has composite-like structure and high-grade environmental adaptive function. In the mechanosensory mechanism of bone remodeling, the osteocyte network system embedded in bone matrix is considered as one of the important elements. This study observed the calcium response of osteocytes isolated from and embedded in living bone tissue matrix to mechanical stimulation. As a result, sensitivity of the cell process was relatively higher than that of the cell body. In addition, the role of cytoskeletal actin structure in the mechanosensory mechanism was discussed in terms of its localized distribution. Finally, we observed the calcium response of osteocytes embedded in living bone tissue matrix in situ. This knowledge can be applied to clarify the relation between macroscopic mechanical stimulation to bone and microscopic mechanosensing of osteocytes.
View full abstract
-
Yukako AKINOU, Masayoshi MIZUTANI, Jun KOMOTORI, Kazutoshi KATAHIRA, H ...
Article type: Article
Session ID: 3313
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The biocompatibility is necessary for the Co-Cr alloy used as an artificial femoral head material. Then, the ELID (Electrolytic In-Process Dressing) grinding is paid to attention as a method of the surface modification and the processing. We focus on the grinding fluid as a factor to control the biocompatibility, and considered the influence that the grinding liquid element exerted on the cell bonding on the surface of the material. As a result, the biocompatibility on the surface of the material has improved when processing it with the grinding fluid with high electric conducitivity.
View full abstract
-
Masakiyo HAZE, Jun KOMOTORI, Toyohiko SHINDO
Article type: Article
Session ID: 3314
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The authors previously showed that a bioactive SiO_2 film coated on Ti-6Al-4V alloy excessively improves the corrosion resistant of the Ti-6Al-4V alloy. Though the corrosion resistant of the hydroxyapatite deposited film is not known yet. In this study, first we coated Polysilazane on to Ti-6Al-4V alloy substrate. Then we applied a treatment which to cure the film to SiO_2. Hydroxyapatite deposition was conducted by soaking to the SBF solution successively. Corrosion resistant of the hydroxyapatite deposited film was investigated by an electrochemical method. The results showed that the formation of hydroxyapatite surface layer significantly improves the corrosion resistant of the prepared Polysilazane derived SiO_2 coating.
View full abstract
-
Aiki YAMAGA, Noriyuki HISAMORI, Yukito HAGIHARA
Article type: Article
Session ID: 3315
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
A bone-like composite that is composed of HA and collagen protein is reported to be bioactive and enhance bone growth. We have reported HA/Col. composite with precipitation method had been replaced by bone within 8 weeks. However, this composite is difficult to have sufficient mechanical property and formability. In this study, we have developed a composite that has improved formability by adding CMC gel to HA/Col. Mechanical property of this composite was evaluated by compressive strength test. Bioactivity was evaluated by soaking the composite in simulated body fluid. Results of measuring Ca^<2+> concentration in SBF after soaking indicate possibility of the bioactivity.
View full abstract
-
Kazuto Tanaka, Koji Kamada, Tsutao Katayama
Article type: Article
Session ID: 3316
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Nature has developed many novel solutions that are often considered to be optimal. Extracting these design solutions from nature is known as biomimetics. Cancellous bone contains trabecular bone (solid) and marrow (fluid), and plays an important role for load transfer of the knee joint. The objective of this research is mimicking the solid-liquid composition of the cancellous bone and developing the material that has the excellent load dispersion ability. In the previous research, the solid-liquid composition of the cancellous bone has been modeled as solid-air composite that was made with Al honeycomb and silicon film. The hydrostatic pressure in cells affected the load dispersion characteristic under static compression. In this study, to investigate the influence of the compression speed, impact tests were carried out. We investigated the influence of directions of holes to cell walls, cell wall thickness, hole diameter and the number of holes on the load dispersion ability. solid-air composites displayed good load dispersion ability under dynamic load.
View full abstract
-
Kazumasa NAKAJIMA, Kiyotaka MASAKI, Yasuo OCHI, Takashi MATSUMURA
Article type: Article
Session ID: 3317
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
In order to investigate the effect of stress concentration on high cycle fatigue property of austenitic stainless steel, rotating bending fatigue tests were carried out with SUS316L having loose circular notch such as curvature radius of 10-40mm and smooth specimen in the air at room temperature and the water cooling. As the results, it was clear that the ratio of stress concentration factor K_t to fatigue strength reduction factor K_f was about 0.907〜1.015(Water-cooling). And also, the method which obtain the fatigue limit of smooth specimen without the water cooling of the test specimen during fatigue test was proposed.
View full abstract
-
Tatsuo SAKAI, Ryohei TAKIZAWA, Tatsuya FURUSAWA, Masaki NAKAJIMA, Kazu ...
Article type: Article
Session ID: 3318
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The authors have developed a new model of multi-type fatigue testing machine in axial loading, in which fatigue tests for four specimens can be performed simultaneously. Setting up the fatigue testing machines at different organizations and preparing a lot of specimens of high carbon chromium bearing steel (JIS: SUJ2), fatigue tests in the ultra-long life regime were performed as a common research project. Thus, the fundamental S-N characteristics were first clarified at the respective organizations, after which all the fatigue test data were pooled altogether and the statistical fatigue property of this steel was analyzed from a viewpoint of the reliability engineering. It was finally found that the P-S-N characteristics in the long life regime were well evaluated by applying the mixed mode of Weibull distribution consisting of fatigue life distributions for surface-induced fracture and interior inclusion-induced fracture.
View full abstract
-
Kazuaki SHIOZAWA, Seiichi NISHINO, Takayuki HASEGAWA, Yasuyuki YACHI
Article type: Article
Session ID: 3319
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Axial-loading fatigue tests were performed under various applied stress ratios in laboratory air at room temperature using hour-glass-shaped specimen of high carbon-chromium bearing steel, SUJ2, and high-speed tool steel, SKH51. Three types of fracture mode were found from the observation of fracture surfaces, such as surface fracture mode as a result of the surface crack initiation and propagation, internal fracture mode governed by a nonmetallic inclusion without formation of GBF area around an inclusion and that with the GBF. Transition of the fracture mode on S-N curve depended on an applied stress ratio. It was concluded from a discussion based on fracture mechanics that change in three types of fracture mode was governed by compressive residual stresses on the specimen surface.
View full abstract
-
Masaaki MISUMI, Masafumi OHKUBO, Kenta NAKAYAMA
Article type: Article
Session ID: 3320
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Super long-life fatigue tests were conducted for the rotating bending specimen shot-peened after radical nitrizing. Circular type, semicircular type fish-eyes and two fish-eyes at a fracture surface were observed. Fatigue life lengthen effect by combined surface treatment of radical nitrizing and shot-peening was not almost recognized.
View full abstract
-
Shigeru DOI, [in Japanese], [in Japanese], Manabu YASUOKA, Takesi MITU ...
Article type: Article
Session ID: 3321
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Rotating fatigue test was carried out using the sintering WC-Co in ultra-long life. A sintered alloy has much defects on the boundary. A crack initiates from these defect, and propagates belong the boundary. Fatigue limit does not exist. Because the sintered alloy like ceramics obeys to weakest link. The boundary slips easily, and is weak to sharing force. The fatigue crack propagation rate (da/dN) cannot calculates. But, fracture toughness K_<IC> can calculate from relationship Fractal dimension or Hurst number and yield area. Yield area of fracture in ultralong N_f=2.05×10^7 broad. Origin of fracture is surface defect s. When K_<IC>>K_<max> in surface stands up, the crack in the plane stress propagate. The fatigue strength of WC cemented carbide is obeyed to weakest link model of defects. Because, even if it supposes that it was worked the cyclic stress over the fatigue strength, the fatigue fracture did not always happen.
View full abstract
-
Yusuke Tanabe, Tomoaki Tsuji, Osamu Fukushi
Article type: Article
Session ID: 3322
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
It has been studied about the identification of the impact force by measuring the sound pressure. In these studies, the transfer functions between the impacted force and the sound pressure were obtained by the experimental method. In this study, the relationship between the impact force and the sound pressure is obtained by the analytical and the numerical calculations. Thus, the transfer function can be obtained without the extra experiment. And the impact force can be given by measuring the sound pressure only.
View full abstract
-
Hidetoshi SAKAMOTO, Shinjiro KAWABE, Kazuyuki SATOH, Masahiro Himeno, ...
Article type: Article
Session ID: 3323
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The fracture mechanics of glass bottles by using underwater shockwaves technique and the recycling process by smashing the glass bottles were discussed. The proposed smashing process can decrease the recycling cost by small grain sizing of "cullet" which is the crashed glass fragments and by overleaping the washing process as the recycling pre-processing. In this study, using commercial beer bottle, the relation between the "cullet" size and various explosive conditions, that is, distance, amount, speed and configuration were clarified.
View full abstract
-
Hidetoshi SAKAMOTO, Kensuke SATO, Tetsuya HIWATASHI, Toshihiko YAMAGUC ...
Article type: Article
Session ID: 3324
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The bullet-firing test was done in the different velocity and collision angle of the bullet. The effect of its velocity and angle on the deformation shape after firing was discussed by comparison with experiment and simulation. The velocity of the bullet was chosen in several kinds of speed ranges at 80m/s-250m/s. As for the angle of incidence with the collision object, four kinds of angles 90°(head-on collision), 45°, 30°, and 60°were set.
View full abstract
-
Satoshi Sakano, Hirokazu Nasu, Shunichi Kawano, Hirofumi Sentoku, Koui ...
Article type: Article
Session ID: 3325
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
By the biodegradability which is one of the characteristics of poly lactic acid, poly lactic acid is expected as a bone screw and a plate for bone fixation. But There are problems such as strength or lack of ductility in mechanical property. In this study, Improvement of strength in poly lactic acid by giving extension processing was planned. There for pulling strength and Bending strength of poly lactic acid in the case of two, three and four times extension rate was examined.
View full abstract
-
Ichiro SHIMIZU, Naoya TADA, Kyosuke SHIBUTANI
Article type: Article
Session ID: 3326
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
The understanding of the multiaxial flow behavior of polycrystalline metals is important not only for the process planning but also for the quality assurance of metal working products. In the present study, the biaxial compression experiments with strain path change were performed on industrial pure titanium using a newly developed testing apparatus. The influences of strain path and abrupt path change upon the mechanical behavior were then investigated. The results show that both the strain level at path change and the directional relation between the sequential paths affect the stress-strain relation of the material. It is also found that the plastic anisotropy has influences on the mechanical behavior with regard to the strain histories.
View full abstract
-
Motoki NAKAJIMA, Tetsuya HONDA, Shin-ichi KOMAZAKI, Yutaka KOHNO
Article type: Article
Session ID: 3327
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Advanced high Cr ferritic steel have a complex lath martensitic structure consisting of several microstructural units, i,e., in the order of their size, fine lath, block and/or packet including several laths, and prior austenite grain which is the largest unit. In addition, precipitation, solid-solution and dispersion strengthening contribute to their strength. However, it is by no means easy to separate the contributions of such strengthening factors and quantitatively understand them because of extremely fine and complicated microstructure. In this study, the instrumented indentation test was carried out under a wide variety of maximum indentation loads using the interrupted creep specimens to clarify the contributions of block to their strength and/or material degradation.
View full abstract
-
Tsuyoshi MAYAMA, Katsuhiko SASAKI, Yoshihiro NARITA
Article type: Article
Session ID: 3328
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Strain amplitude dependent cyclic plasticity of SUS316L under room temperature is investigated experimentally and theoretically. Tension-compression cyclic loading tests at a constant strain rate with three different strain amplitudes show that cyclic hardening and softening behavior depends on the strain amplitude. A modified macroscopic constitutive model describes the experimental results successfully. Dislocation structure images observed by using transmission electron microscope (TEM) are evaluated qualitatively and quantitatively. A relationship between material parameters in the model and the evolution of dislocation structure is discussed.
View full abstract
-
Ayumi SEMBA, Tadashi HASEBE, Yoshihiro TOMITA
Article type: Article
Session ID: 3329
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
This study intends to clarify the mechanical roles and structural stability of cell wall structures for crystalline solids by utilizing discrete dislocation dynamics method. Cell walls with several densities and interspacings (i.e., cell size) made up with periodically aligned dislocations and redundant dislocations are artificially constructed in a unit cubic area. The redundant dislocations whose resultant Burgers vector produces compressive stress field in the cell interior region are introduced to enhance the long range internal stress fields.
View full abstract
-
Nobuhiro TSUJI
Article type: Article
Session ID: 3330
Published: September 15, 2006
Released on J-STAGE: August 01, 2017
CONFERENCE PROCEEDINGS
RESTRICTED ACCESS
Ultrafine grained steels having mean grain sizes much smaller than 1μm can be realized nowadays at least in laboratory scale. The present author has systematically studied the mechanical properties of the ultrafine grained steel sheets with wide range of mean grain sizes. Ultrafine grained steels perform peculiar mechanical properties, that are not only very high strength but also other nice aspects like excellent low-temperature toughness. Furthermore, quite unusual deformation behaviors that have not yet been reported in conventionally coarse grained metals can appear in the ultrafine grained metals All these features of the mechanical properties of ultrafine grained metallic materials will be reviewed.
View full abstract
