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沖本 邦郎
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発行日: 2006/09/15
公開日: 2017/08/01
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The anisotropies of sound velocities in sintered Sr-ferrites compacted under a magnetic field were investigated by an ultrasonic pulse method. The direction of the applied magnetic field was parallel to that of the compacting pressure. The magnetic field strength was 675kA・m^<-1>, while the green compact was 32mm long, 7mm wide and approximately 7mm high. Compacting pressures of 50MPa and 100MPa were used and three different sintering temperatures were employed, namely 1200℃, 1225℃ and 1250℃. The two directions of the applied sound waves were parallel to the direction of the magnetic field and the compacting pressure, and perpendicular to these directions. The anisotropy of the longitudinal sound velocities was greatest in the orientated sintered compact, the maximum difference between the two velocities was about 8% for such samples. In contrast, the anisotropy of transverse sound velocities was less than 3%. In addition, some anisotropy in the longitudinal sound velocities in the non-orientated sintered compact was detected. This is due to the fact that mechanical alignment of the magnetic particles occurred during the compacting process. The sound velocities were unaffected by the bending strength test. The sound velocity was higher for samples sintering at higher temperatures, but it did not vary with the compacting pressure. This is due to the fact that the sintered density increases with the sintering temperature, but is hardly affected by the compacting pressure. Young's modulus, the shear modulus and Poisson's ratio were estimated from the measured sound velocities using the equations for an isotropic elastic body, since the anisotropy of sound velocities by the orientation forming were 10% or less. In the length direction of the test piece, the greatest rate of change in Young's modulus due to orientation was 7%, while that for the shear modulus was 5% and that for Poisson's ratio was about 10%. In the case of the width and height direction of the test piece, the largest rate of change in the above-mention parameters were approximately 2%, 2% and 16%, respectively.
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池田 潤二, ペッツォッティ ジユセッペ, 下園 隆祥, 近藤 誠
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発行日: 2006/09/15
公開日: 2017/08/01
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The changes in the residual stresses and crystalline forms on the local area of 3mol% yttria stabilized tetragonal zirconia polycrystalline (3Y-TZP) and high-purity alumina for artificial joints were examined by Raman spectroscopy technique. The stress dependence of the peak positions of Raman/fluorescence spectra was estimated by four-point bending method, and then the residual stress and monoclinic fraction around the Vickers indentation were determined In both 3Y-TZP and alumina, there was a linear relationship between the peak position and the applied stress. As for 3Y-TZP, about 10vol% transformation and compressive residual stress areas were observed in the vicinity of the indentation, whereas tensile residual stress area was observed in the crack tip. Raman spectroscopy technique is useful for evaluating residual stress in ceramic artificial joints.
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池田 智香子, 若山 修一, 池田 潤二
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発行日: 2006/09/15
公開日: 2017/08/01
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AE monitoring was conducted during proof tests of the high-purity alumina ceramics in order to detect microdamages which might degradate the strength of surviving components. The tested material in this study is the bioceramics used in artificial joints for total hip replacement (THR). Surviving specimens showed two types of AE behaviors, with or without increasing point of AE energy. Specimens without increasing point of AE energy showed higher residual strength than specimens with the AE increasing point. In addition, the average strength of specimens without increasing point of AE energy was higher than specimens which survived the conventional proof test. The AE source location during measured residual strength demonstrated that the maincrack formed during proof tests were propagated to final unstable fracture during residual strength tests. Consequently, it was understood that the proof test with AE monitoring of microdamage enhances significantly the reliability of bioceramics.
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地曳 武彦, 若山 修一, 池田 潤二
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発行日: 2006/09/15
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Fracture toughness test of bioceramics using alumina compact tension specimen was carried out in air and water. During this test acoustic emission signal emitted by microcrack nucleation were recorded by piezoelectric transducers. The response function of the specimen was determined by pencil lead breaking used as a simulated source. Then acoustic emission source function emitted by microcrack nucleation was also determined by inverse calculation using obtained response function. From acoustic emission source function, size and nucleation velocity of microcrack were understood. Consequently, it was understood that microcracks with 6.6〜17μm of diameter and 9.5〜47m/s of nucleation velocity were nucleated in air. On the other hand, in water, the radius was 13〜22μm and the nucleation velocity was 26〜86m/s. Then quantitative microcrack characterization was carried out.
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板橋 遊, 松村 隆, 越智 保雄
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セッションID: 2735
発行日: 2006/09/15
公開日: 2017/08/01
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Due to its filterability and thermostability, porous ceramics have a large attention as a suitable material for filters such as a diesel particulate filter. Since damages induced by contact stress on filters cause serious degradation of their strength and life span, the standardization of sphere indentation test is necessity to evaluate the indentation strength of porous ceramics quantitatively. The sphere indentation examination was carried out to investigate the effects of pore diameter on indentation strength. Three porous ceramics were tested ; each porous ceramic contains different pore diameter. The result shows that indentation load increased monotonically along with an increase in indentation depth when the porous ceramic has small diameter. However, with a larger diameter, the graph of load-displacement displays load non-monotonically increases with vertical fluctuation. The strength of specimen with larger pore diameter relies on indentation sphere size. While the ceramics strength with smaller pore diameter stays constant, the strength of larger one rises with increasing sphere diameter.
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阿部 豊, 岡部 永年, 高橋 学, 豊田 繁, 藤木 健伍
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セッションID: 2736
発行日: 2006/09/15
公開日: 2017/08/01
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Ceramics have the properties of high-stiffness, proof-corrosion, and light-weight superior to metal materials and so have been applied to a ball and a race in high performance ball bearing and etc. As a recent expansion of this application, a ceramics ball has been applied to the backflow valve, which is comprised in automotive fuel supply system. However, it must be considered sufficiently that ceramics balls can be kept a high confidence over long-term without being broken down by cyclic contact loadings, which generate between a ceramics ball and housing on switching of the backflow valve. In this investigation, the stress analysis by FEM was conducted for clarifying failure mechanism due to cyclic contact stress. As result of analysis, high stress place was seen in contact side neighborhood of a ball and housing. Ceramics is brittle material, predominant of the fracture is a microscopic crack in materials. Therefore, author clarified that an initial surface microscopic crack was a starting point of fracture.
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田中 啓介, 秋庭 義明, 北 泰樹
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セッションID: 2737
発行日: 2006/09/15
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Sharply notched specimens of porous silicon carbide with porosity 37% were fatigued undercyclic four-point bending. The crack propagation curve was divided into stages I, II and III. The crack propagation rate first decreased with crack extension in stage I and became constant in stage II. In stage III, the crack propagation rate increased. The transitions from stage I to II and from II to III took place at constant values of crack extension. The anomalous variation of the crack propagation rate as a function of the crack length or the stress intensity factor was caused by crack-tip shielding due to crack face contact. The amount of crack-tip shielding was estimated from in-situ SEM observation of crack opening behavior of cracks.
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高橋 宏治, 内出 健一, 中尾 航, 安藤 柱
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セッションID: 2738
発行日: 2006/09/15
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斧 督人, 中尾 航, 高橋 宏治, 安藤 柱, 中谷 雅彦
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セッションID: 2739
発行日: 2006/09/15
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藤田 幸人, 本村 寿登, 合田 公一, 大木 順司
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セッションID: 2740
発行日: 2006/09/15
公開日: 2017/08/01
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Laminated SiC whisker reinforced Al_2O_3 matrix ceramics with three and six layers were fabricated through hot-press method and their bending strengths and fracture toughness were evaluated by three-point bending tests, where Al_2O_3 layer was set to tension side and namely composite with higher V_fto compression side. The bending strengths of the materials with both three and six layers were lower than that of monolithic Al_2O_3. This result could be due to nucleation of crack around the interface between the Al_2O_3 layer and the neighboring composite layer. The fracture toughness in the three-layer materials was relatively higher than in the monolithic Al_2O_3 and in the six-layer materials. From the residual stress analysis considering the cooling process in the fabrication, compressive residual stress, which could restrict the crack growth, was confirmed near the crack tip only in the three-layer materials.
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伊藤 瞬一, 福本 功, 中山 清光, 銘苅 春榮
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セッションID: 2741
発行日: 2006/09/15
公開日: 2017/08/01
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The composite materials mixed with coal ash and Kucha clay were fabricated by Spark Plasma Sintering (SPS). By changing the ingredient ratio of coal ash and clay, the mechanical properties were investigated in terms of specific gravity, micro vickers hardness and bending strength. The composite material including coal ash 95% and clay 5% (mass%) sintered at firing temperature 1473K ON SPS showed the highest strength 87.5MPa in the bending test.
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恒川 卓也, 水谷 健介, 白木原 香織, 來海 博央, 田中 啓介, 安藤 裕介
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セッションID: 2742
発行日: 2006/09/15
公開日: 2017/08/01
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Piezoelectric ceramics are widely applied to the components of electric devices and actuators. Therefore, the reliabilities of PZT are very important. In this study, the domains in a crystal of PZT were observed by the EBSP method. However, it was very difficult to observe the crystal orientations and domains by EBSP method, because PZT ceramics were non-conducting materials and solid solutions. But, by using the acid chemical etching in combination with mechanical polishing for specimen surface finishing, the laminar domain structures on a nanoscale, were able to be observed by EBSP method. In addition, in-situ observation of domain switching behavior under mechanical loading was conducted by four-point bending tests of notch specimens in scanning electron microscope. The specimen was poled in the across-the-width direction (PS specimens) parallel to the crack front line. During the mechanical loading, the mechanical loading-induced domains switching were observed by EBSP method. Especially, the domain switching was most obvious in the intensity change of the <001> pole figure. The c-direction before loading was changed into two mutually-perpendicular directions by the mechanical loading.
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鎌土 重晴, 伊藤 正太, 高辻 則夫, 高橋 泰, 村井 勉, 吉田 晃, 板倉 浩二
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セッションID: 2743
発行日: 2006/09/15
公開日: 2017/08/01
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Authors attempt to improve proof stresses and their anisotropic properties of Mg-Al-Zn wrought alloys by microstructural controls utilizing dynamic recrystallization and dynamic precipitation during hot extrusion. In the alloy specimens extruded at lower temperatures increasing Al and Zn contents enhance dynamic recrystallization and dynamic precipitation, resulting in grain refinement and large amount of Mg_<17> Al_<12> precipitates. As a result, the extruded Mg-9%Al-1%Zn alloy specimen shows high tensile strength of 370MPa, 0.2% tensile proof stress of 240MPa and moderate elongation of 20%, which are comparable to those of T5-treated 6N01 Al extruded alloy. Furthermore, a ratio of compressive proof stress to tensile proof stress of the as-extruded specimen improves up to a higher ratio of 0.9 than that of Mg-3%Al-1%Zn alloy specimen with no precipitation, 0.5, due to prevention of tensile twin, which easily occurs during compressive deformation even under a low applied stress perpendicular to the extrusion direction, by dynamic precipitation of Mg_<17> Al_<12> phase.
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川口 修平, 伊藤 正太, 鎌土 重晴, 小島 陽, 大石 幸広, 河部 望, 森 宏治
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セッションID: 2744
発行日: 2006/09/15
公開日: 2017/08/01
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Tensile properties and microstructural evolution of drawn AZ-31 and AZX311 alloy wires during tensile and twist deformation were investigated at room temperature. Furthermore, microstructure changes of annealed pipes with bending deformation was also examined at room temperature. An addition of 0.88% Ca to AZ31 alloy enhances grain refining effect by finely-dispersed Al-Ca compound, and prevent grain coarsening during annealing. As a result AZX311 exhibits higher tensile strength and proof stress by about 20% than AZ-31 alloy and has high elongation even after the high temperature annealing. It is possible to bend at the minimum radius of 2.7D in AZ31 alloy pipe annealed at 3009C. At the inside of the bent area texture of basal plane rotates by about 90℃along the drawn direction due to occurrence of tensile twin, but the texture at the outside unchanges.
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三野 峻, 浅川 基男, 藤原 高礎, 松崎 邦男, 鳥阪 泰憲, 小林 勝
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セッションID: 2745
発行日: 2006/09/15
公開日: 2017/08/01
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Continuous strip casting and direct rolling method are receiving attention as the integrated producing process to obtain wrought Magnesium alloys. In this research, AZ61 strip was cast from molten metal by twin-roll strip caster and it was rolled by "Structure-Control rolling process". The effects of casting conditions and rolling parameters on surface aspect and microstructure of the rolled sheet were investigated. Obtained results are as follows: (1) By using structure-control rolling with R.T. pass, microstructure of the mean grain size of 5μm was obtained. (2) By lowering starting rolling temperature, mean grain size and duplex grain size degree decreased and hardness increased. In addition, the deformation resistance decreased and the fracture strain increased.
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松岡 信一, 細川 貴成, 村井 勉, 中川 文昭
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セッションID: 2746
発行日: 2006/09/15
公開日: 2017/08/01
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Cold rolling and heat treatment for magnesium alloy extruded sheets have been investigated. By cold rolling, mechanical properties show anisotropic characteristic, and that remained after heat treatment. In this study, tried to hot rolling and annealing for extruded magnesium alloys. And studied on their mechanical properties and internal structure, surface roughness. The optimum condition of hot rolling was clarified, in order to make the best qualities of magnesium sheets.
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阿久澤 功, 半谷 禎彦, 北原 総一郎, 天田 重庚, 吉川 暢宏, 桑水流 理
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セッションID: 2747
発行日: 2006/09/15
公開日: 2017/08/01
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Die-casting tends to generate casting defects during the production process. In an attempt to reduce the casting defect, we carried out the compression test of ADC12 aluminum alloy die castings in cylinder-shaped at high temperature. To evaluate the efficiency of reduction of casting defects, first the nondestructive tests were carried out by X-ray computed tomography. Next, three-dimensional images were obtained from X-ray computed tomography images by using "VOXELCON". From these three-dimensional images, the shape of the casting defects was observed and the reduction state was evaluated. The casting defects in the specimens become less when the compression strain of specimens becomes higher. We concluded that, applying compression load is effective to reduce casting defects.
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近藤 勝義, 川端 健詞, 荻沼 秀樹
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セッションID: 2748
発行日: 2006/09/15
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A superior balance of high strength and high ductility is very important in applying wrought magnesium alloys to structural components. The improvement of their plastic deformability is also strongly required in the practical use. Grain refinement and texture control are useful to break through the technical issues. In this study, Roll Compaction (RCP) process is applied to produce hot extruded magnesium alloys with fine grains less than 1-3μm in employing AZ31 alloy coarse powder as input materials. They show high tensile strength of 360-38OMPa and good elongation of 15% in room temperature, compared to the conventional wrought AZ31 alloys.
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荻沼 秀樹, 川端 健詞, 近藤 勝義
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セッションID: 2749
発行日: 2006/09/15
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Mg-Si alloy have high potential as heat resistant light metals because Mg_2Si exhibits a high melting temperature, low density, low thermal expansion coefficient and a reasonably high elastic modulus. On the other hand, the microstructural refinement serves the important of mechanical properties. In this work, magnesium alloy powder refined the grains was produced by roll compaction (RCP) process. And Bio-silica^[○!R] was used to synthesized Mg_2Si and MgO by reaction with magnesium alloy, and Mg_2Si/MgO/Mg composites were produced. The Bio-silica^[○!R] was high purity SiO_2 made from rice husk ash. It shows a good mechanical property could be fabricated by hot extrusion using a mixture of magnesium alloy powder and Bio-silica^[○!R].
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吉田 一也, 高橋 健司, 清水 泰宏
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セッションID: 2750
発行日: 2006/09/15
公開日: 2017/08/01
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Recently, the magnesium alloy that is light and high strength has been attracted attention, its used such as body of computers, mobile phone and so on. However plastic working of the alloy is very difficult, must be warm and hot working necessary. Furthermore, the production of products with complicated shapes using the alloy is difficult, the processing cost is high. In this study, reduction by cold drawing inquires for high strength quality and surface morphology. In addition using the magnesium alloy fine wires obtained in this study, making microscrews by rolling and heading.
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坂本 英俊, オリビエ フルニエ, 河端 洸輔, 樋渡 哲也
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セッションID: 2751
発行日: 2006/09/15
公開日: 2017/08/01
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The deep drawing test in magnesium alloy sheet AZ31 was executed and the authors discussed the effect of the test conditions (temperature, lubricant, blank holding pressure and processing speed, etc.) on the formability. As a result, we obtained as follows: (1) In the case of lubricant CF-853 added with the Teflon powder, the good states of deep drawing was obtained. (2) A blank holding load of 8OkN was found as a good value to prevent the flange wrinkle. (3) 1mm thickness AZ31 sheets shows poor formability less than 160℃ and shows the good formability at 200℃ for any speed.
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木下 明, 邱 然鋒, 吉田 慶一, 岩本 知広, 里中 忍
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セッションID: 2752
発行日: 2006/09/15
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We applied the resistance spot welding with cover plates to high strength magnesium alloys Mg_<96>Zn_2Y_2. The cover plates is to keep a heat to welding area for spot welding of the high thermal conductivity materials. The welded specimen Mg_<96>Zn_2Y_2/Mg_<96>Zn_2Y_2 exhibited tensile share strength more than 750N at the welding current of 1880A. Mg_<96>Zn_2Y_2/SUS304 exhibited a high tensile share strength more than 1200N at the welding current of 1980A. The Vickers hardness of weld area is about 10 higher than that of base metal. High hardness of nugget is considered to be originated from the fine long period stacking order (LPSO) phase dispersion observed by cross-section transmission electron microscope.
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前川 克廣, 羽生 謙市, 村上 敬, 梅田 一徳
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セッションID: 2753
発行日: 2006/09/15
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The present study aims to develop a dental implant with interconnected pores that enable tissue regeneration. The implant can be fabricated by a combined technology of rapid prototyping with spark plasma sintering (SPS) using titanium sheet made of a pure powder. This paper reports the evaluation of basic properties of the laminated titanium sheet that has been sintered by the SPS method, followed by the investigation of a technology for controlling internal cell structures. The use of NaCl powder in the SPS process plays an essential role in the retention of pores as well as outer shape of the implant.
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塩見 誠規, 今釜 俊介, 小坂田 宏造
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セッションID: 2754
発行日: 2006/09/15
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A method for fabricating aluminium foams from powder mixed with foaming agent is presented. Aluminium powder with foaming agent, TiH_2, is compacted and extruded to the die heated by an induction heater. The Al compact including TiH_2 is heated to a temperature more than the liquidus temperature and is extruded into the mold during foaming. The distribution of relative density within the Al foams formed with a pipe is in a range of 0.2 and 0.3 by controlling the pipe temperature. To evaluate the energy absorption of the pipe with the Al foams, a compression test by using a press is conducted. The energy absorbed by the pipe with foams is higher than that by the pipe without foams.
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吉村 英徳, 品川 一成, 鮭川 佳弘, 三原 豊
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発行日: 2006/09/15
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Aluminum foams are an attractive material which can reduce the car weight and can improve the rigidity of a car and the energy absorption in a car collision. In this study, to apply the foams to car-parts like a B-pillar and a bonnet, the bending property of the foams and possibility of the fabrication of car-parts by bending are examined. To improve the bending limit of aluminum foams which have a weak point for the tensile deformation, experiments with a warm working and with various radii of bending jig and FEM analysis of sandwich structures are carried out.
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清水 透, 松崎 邦男
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発行日: 2006/09/15
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Already, we are developing the process to produce stainless steel foam over 97% porosity using hydro-gel binder. However, this process is very sensitive process, and foaming condition is affected by the slight deference of heating temperature. Therefore, we tried to improve the process by changing the foaming agent and foaming conditions. By the improvement of the process, the foaming operation becomes stable and finer cell size stainless steel foam can be obtained.
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品川 一成
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セッションID: 2757
発行日: 2006/09/15
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Fabrication of graded pore structure in porous metal is attempted by powder method. Layers of aluminum powder mixed with different amounts of a foaming agent are compacted into cylindrical precursors and heated up in a furnace with or without tubular molds. The influence of molding on the shape change and the pore formation in the precursors is examined. The distortion of the precursors due to graded foaming under gravity is suppressed by molding, and the pore distribution can be also produced unless excessive constraint of deformation is imposed.
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西籔 和明, 平尾 洋, 松崎 覚, 田中 茂雄
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セッションID: 2758
発行日: 2006/09/15
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A novel production method for the metal components with micro-sized porous structures has been developed by applying powder space holder (PSH) method to metal powder injection molding (MIM) process. This method is capable of manufacturing with high dimensional accuracy the micro-porous metal components with complicated shapes using most kinds of metal powder. The size of metal powder and space holding particle in addition to sintered temperature are main factors affecting significantly for the pore size, porosity, surface area and shrinkage of sintered porous metals. The method proposed is useful in producing the graded porous structure for high functionally.
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平尾 洋, 西籔 和明, 品川 一成, 松崎 覚, 田中 茂雄
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セッションID: 2759
発行日: 2006/09/15
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A novel production method for the metal components has been developed by applying powder space holder (PSH) method to metal injection molding (MIM) process. Micro porous metals which have controlled closed or open pore structures are produced by PSH-MIM method. It is important for producing the products with high-quality to understand the effects of material combination and sintering temperature on pore size and porosity. The aim of this study is to investigate the effectiveness of the numerical analysis for their prediction. The analytical results showed the similar tendency to the experimental ones on sintering shrinkage of porous metals prepared using various volume fractions of space holding particle.
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福田 晴一, 前川 克廣
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セッションID: 2760
発行日: 2006/09/15
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Titanium is widely used in orthopedic implants as prostheses for joint replacement because of its excellent mechanical properties and biocompatibility. The present research aims to fabricate titanium porous scaffolds to promote bone or tissue ingrowth into pores and provide biological anchorage. A novel 3D modeling method is proposed in this work for controlling internal porous structure and outer shape. A piece of titanium sheet formed with micro powder, polymeric binder and organic solvent is sintered by Nd: YAG laser to form a 2D bone-like cross-section. These 2D layers each of 140μm thickness are temporarily laminated to build a 3D porous scaffold. Finally, the pre-laminated part is sintered using the spark plasma sintering (SPS) method. Space holding particle is one of the important sintering parameter during the SPS process. The experimental result shows that the use of NaCl space holding particle yields an excellent surface condition of the porous scaffold when it is sintered under a temperature of 630℃ and a pressure of 4MPa.
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園部 圭一, 前川 克廣
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セッションID: 2761
発行日: 2006/09/15
公開日: 2017/08/01
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For the purpose of making prosthetic implants, we have fabricated porous titanium with threedimensionally distributed micro and macro pores by using a combined method of lamination modeling and spark plasma sintering. Yield strength by compression is varied from 113 to 280MPa by changing the size of macro pores, but the specimen meets strength conditions for almost all teeth. A Young's modulus of 4.0GPa is nearly equal to that of actual teeth, whereas a bend strength of 30MPa is a little bit lower. Next, we have investigated bioactivation of the porous titanium fabricated by the lamination modeling with laser. Alkali and heat treatments are followed by soaking the specimen in simulated body fluid for two weeks. The formation of apatite was observed in the interior of pores as well as on the surface.
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藤田 昌幸, 海江田 健作, 植野 薫文, 岩本 知広, 里中 忍
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発行日: 2006/09/15
公開日: 2017/08/01
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This study deals with the nondestructive discremination between the corona bond and the nugget in the spot welds using a newly developed ultrasonic measurement with the line focussed probe. Four types of spot welded specimens were prepareed. The transmission charactaristics of ultrasound in the nugget was investigated by the measurement of one sheet specimen, which were made by grinding after removing upper plate of spot welds. The nugget size was measured by the scanning measurement over the spot welded specimens with and without the indentation. The measurement result of one sheet specimen showed that the reflected wave from the back wall in the nugget exhibited higher or lower amplitude than that in the base metal, which depended on the water path in the measurement. The scannning results of spot welds also showed that the nugget was possible to discriminate from the corona bond as long as the indentation in the surface was shallow.
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原 宏太, 三木 則尚, 菅 泰雄
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セッションID: 2802
発行日: 2006/09/15
公開日: 2017/08/01
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Penetration control during welding is an important function of intelligent welding robot. Therefore the oscillation model of the molten pool was investigated to estimate and control the back bead width in TIG arc welding of thin steel plates. Recently, Yoo et al. proposed an analytical model of molten pool oscillation using the energy method. In their research, the molten pool is assumed to have a tapered cylindrical shape with elliptic free surfaces when it is in full penetration. The similarity ratio of top to bottom surface and thus, the back bead width are calculated using parameters including natural frequency, geometry of top surface, plate thickness and so on. Therefore, a welding penetration control system, in which the welding process is monitored via an arc sensor and a visual sensor, is constructed. The effectiveness of the system is demonstrated by automatic welding experiments of thin stainless steel plates.
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宮下 幸雄, 谷内 大世, Rattana Borrisutthekul, 武藤 睦治
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セッションID: 2803
発行日: 2006/09/15
公開日: 2017/08/01
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Dissimilar metals laser welding technique was developed by using solid/liquid state reaction at the interface. However, intermetallic phase (IMP) formed at the interface of a dissimilar metals joint reduces strength and reliability due to brittleness and weakness of IMP. In the present study, a controlling technique for IMP formation at the interface of steel/aluminum alloy dissimilar metals laser lap joint was studied. Effect of applying a contact block (backing plate) on weldability and strength of the joint was investigated in FEM analysis as well as welding experiment.
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松岡 信一, 向 和宏, 今井 久志
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セッションID: 2804
発行日: 2006/09/15
公開日: 2017/08/01
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The ultrasonic welding technique can be carried out in many different ways, such as in direct welding metal/metals. This paper gives a description of an experimental study of the ultrasonic welding of aluminum and cupper at room temperature and water bath, both quickly and easily when compared to other welding methods. When controlling the ultrasonic power, it is thought that the welding characteristic can be guessed. Also, welding in the water bath can be small heat affected zone.
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石黒 智明, 松岡 信一
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セッションID: 2805
発行日: 2006/09/15
公開日: 2017/08/01
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This paper gives a description of an experimental study of ultrasonic welding of 20% cold-rolling A1050 sheet which thickness is 0.1 to 0.40mm and anodized aluminum. Consequently, although the ultrasonic vibration output increased with increasing of required duration in the early time, the ultrasonic vibration output declined rapidly with interface vibration fixation. This interface fixed time increased with the increase in Al sheet thickness. And the anodized aluminum by 80V for 1hr in oxalic acid solution (4℃, 4mass% ), it can weld without spoiling the electric insulation of the anodic oxide film.
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渡辺 浩, 光畑 浩一, 上田 圭司, 明賀 俊治, 永島 利治
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セッションID: 2806
発行日: 2006/09/15
公開日: 2017/08/01
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An ultra compact orbital welding equipment for butt welding of water-wall tubes of power generating boilers at erection sites has been developed. The minimum radial clearance of the welding head is 17mm, and this value is minimum in the world. To achieve the 17mm radial clearance, the new arc length control mechanism and the flat welding torch of 7mm thickness have been developed. The differential motion mechanism was used for the arc length control, and the driving gears were set up in the part fixed to the tube. To make the flow of the shielding gas a laminar flow, the filter was set up at the gas blow exit of the thin torch. Using the developed orbital welding equipments, several thousand joints of water-wall tubes of power generating boiler have been successfully welded at erection site.
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鈴村 暁男, 稲垣 洋平, 池庄司 敏孝, 山崎 敬久
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発行日: 2006/09/15
公開日: 2017/08/01
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Braze Pressure Welding (BPW) with high frequency induction heating is a newly developed pressure welding technique using interlayer metals for welding the general steel pipes for pipe arrangement in buildings. At a joining temperature in this method, the melted interlayer removes contaminations from the joining surface of the base metal. Then the liquid filler is discharged from the joining interface by the joining pressure, and forms fillets at the gaps around the joint. The fillets have the effects both on relaxing the stress concentration at the joint and on increasing the joining area, which contribute to the strengthening of the joint. Thus, the high quality pipe joining without the dispersion in joint properties due to welder's skill can be performed. In this report, applicability of the BPW technology to austenitic stainless steel pipe joint is investigated and discussed on the results of microscopy and tensile tests of the joints.
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今井 久志, 松岡 信一
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セッションID: 2808
発行日: 2006/09/15
公開日: 2017/08/01
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The Ultrasonic welding has made possible to weld various ceramics to various metals at room temperature, quickly and easily compared to other welding methods. In addition, the weldability is improved by preheating. This paper shows to be possible to weld Al, Cu, Ag, and Mg (AZ31) in Si_3N_4 directly used ultrasonic vibration. Using the low melting metal, the weldability is better, welding strength is higher, and welding energy is lower. The welding energy used by ultrasonic welding is less than that used for resistance welding.
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坂本 光, 馬渕 信太, 森田 辰郎, 飯塚 高志
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セッションID: 2809
発行日: 2006/09/15
公開日: 2017/08/01
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Tensile strength, fatigue strength and deep drawability were investigated for the joined material consisting of aluminum alloy (A6061) and rolled steel plate (SPCC). The joining between the above different metals was made by friction stir welding method. The tensile and fatigue strengths of the joined material were at 85% and 77% of those of uniform A6061 alloy. After aging treatment, they were improved to 96% and 85%, respectively. On the other hand, the deep drawabiltiy of the joined material was the same as that of uniform A6061 alloy and it was independent with aging treatment.
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広田 健治, 木口 勝慈, 北村 憲彦, 鵜飼 須彦, 松永 啓一
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セッションID: 2810
発行日: 2006/09/15
公開日: 2017/08/01
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Joining two or more parts by forming is an economical method in manufacturing complex shaped products. In this study, we discuss a form joining process to provide high torsional strength for shaft products. Experiments to join a shaft of quenched steel and a thick flange of mild steel was carried out. Joining was achieved by forming the hole of flange with a serrated shaft. The Formed joint was compared with a mechanically fitted one having the same shape and joining area, which proved that the joint by forming had higher torsional strength than that by fitting. One of the reasons was work hardening of formed serrations, which was evaluated by finite element analysis.
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山下 実, 服部 敏雄, 西村 尚哉, 奥山 智仁
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セッションID: 2811
発行日: 2006/09/15
公開日: 2017/08/01
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A trial for controlling the progressive collapse of the square section tube is conducted, in which the inertia force of the weight is used as a trigger for starting the deformation just after the impact. It is demonstrated numerically that the onset of the collapse is controlled for the straight tube or the sigmoid tube. Impact experiment with the aid of the drop-hammer is also carried out, where the impact velocity is 6m/s. Observing the impact deformation with a high-speed video camera, the onset of the collapse is found successfully controlled.
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日向 毅, 濱田 洋史, 伊東 繁
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セッションID: 2813
発行日: 2006/09/15
公開日: 2017/08/01
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In recent years, demand of a Magnesium alloy is increasing as a lightweight material. However, forming of Magnesium alloy in room temperature is difficult. Therefore, development of new Mg alloys and new forming methods are under investigation. In this research, the explosive forming method is used for the forming AZ31 Magnesium alloy. The explosive forming method is one of the high velocity forming methods, which enables achieving a high plastic deformation for some alloys. The purpose of this research is development of a device that can safely do the high temperature explosive forming.
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井山 裕文, 日向 毅, 伊東 繁
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セッションID: 2814
発行日: 2006/09/15
公開日: 2017/08/01
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In recent years, lightening the material of the car body has been attempted for fuel cost reduction. The aluminum alloy has been used as a countermeasure. However, the forming limit of aluminum alloy is less than steel. Therefore, damage ofthe aluminum alloy happens when the car body is formed using conventional punching methods. However, since aluminum alloy has a special feature, when the strain rate exceeds 1000/s, we proposed use of explosive forming method in which strain rates much more than 1000/s can be obtained. Common practice of explosive forming includes the explosion of an explosive in a pressure vessel filled with water. A purpose of our study is examining the forming limit of aluminum alloy plate. In the experiments carried out, the quantity of explosive, the so-called stand off distance and water vessel were changed. Two types of water vessels were used in these experiments ; closed metal vessel and paper vessel. The metal plate is deformed by the underwater shock wave at a speed of several hundred m/s. However the deformation speed of the plate due to expansion of detonation gas is in the order of a few ten m/s. The effects of this gas expansion pressure have been explored.
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濱嶋 英樹, 日向 毅, 濱田 洋史, 伊東 繁
原稿種別: 本文
セッションID: 2815
発行日: 2006/09/15
公開日: 2017/08/01
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It has been difficult to effectively and accurately form materials, such as aluminium based alloys, using conventional methods. Recently, explosive forming with a capability of producing larger deformations than is possible with normal static press forming has become an interesting research topic and is seen as an alternative to traditional methods. However, when the affecting pressure wave is too large, the metal sheet may be destroyed. Explosive forming using underwater shockwaves is examined in this research paper through both experiment and numerical simulation. The explosive forming was performed using the free stretch forming method, allowing a better understanding of the basic mechanisms and characteristics. Numerical simulations are performed in three dimensions using the LS-DYNA code. Experimental and numerical results are seen to correspond to a high degree.
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吉良 章夫, 水野 顕人, 藤田 昌大
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セッションID: 2816
発行日: 2006/09/15
公開日: 2017/08/01
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In this report, deformation process of a circular metal pate supported at its periphery under uniform impulsive pressure is investigated by numerical simulation and it is clarified the duration of pressure pulse gives a great effect on the deformation process. When the duration is very short, a plastic bending wave generated wear the supported periphery of the plate moves toward its center and the plastic deformation is performed according to the movement of the bending wave. When the duration is longer than the time till the bending wave arrives at the center, the plate is gradually bulged over the whole area according to the pressure action. Thus the mechanism of the plastic deformation changes depending on the duration of pressure pulse.
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白本 和正, 井山 裕文, 氏本 泰弘, 甲斐 彰一郎, 藤田 昌大, 伊東 繁
原稿種別: 本文
セッションID: 2817
発行日: 2006/09/15
公開日: 2017/08/01
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In this report, we propose a new explosive welding method, and the welding is performed at employing underwater shock pressure produced by the underwater explosion of an explosive placed at one side almost vertical to the specimen to be welded. In order to prevent the reduction of the shock pressure with the distance away from explosive, a steel reflector is placed over the area of the specimen. The effects of the reflector are investigated based on the experimental results and the process is numerically analyzed results.
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森 昭寿, 外本 和幸, 藤田 昌大
原稿種別: 本文
セッションID: 2818
発行日: 2006/09/15
公開日: 2017/08/01
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A method of explosive welding using the shock wave generated by the detonation of explosive in water is developed by some of authors. In this paper, it is confirm that the use of linearly increasing the thickness of explosive in proportion to the distance from the explosive surface makes a good welding for the metal combinations, which is difficult to weld by conventional joining technique. And these experimental results are compared with the method of explosive welding using underwater shock wave when the thickness of explosive is constant. Moreover, the important parameters for the weldable conditions, like as the horizontal collision point velocity, the collision angle and the collision velocity, are calculated based on the results of numerical simulations for both methods and compared the experimental results.
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田中 茂, 外本 和幸, 伊東 繁
原稿種別: 本文
セッションID: 2819
発行日: 2006/09/15
公開日: 2017/08/01
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A new attempt in development of a composite material was attempted. In this technique, the overall heat conducting of the composite is improved by penetration of diamond powders, which possess high heat conductivity property. Shock wave derived from detonation of explosive is a viable technique and can be used to penetrate diamond powders into the metal plate. The diamond powders placed on the surface of metal plate is penetrated by the effect of pressure shock wave, thus rendering the composite an increase in heat conducting. The purpose of this research is to clarify the experimental conditions for obtaining a new composite material with unique properties. The experimental method and the results are reported.
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吉良 章夫, 友重 竜一, 氏本 泰弘, 外本 和幸, 藤田 昌大
原稿種別: 本文
セッションID: 2820
発行日: 2006/09/15
公開日: 2017/08/01
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A new method has been developed to generate an extremely high impulsive pressure by using the converging of metal jets. The metal jet is discharged from the collision points, when the metal plate accelerated by the detonation of an explosive collides with a conical concave metal block. The metal jets discharged fly toward the center and collide on the central axis. Then the metal jets exhibit extremely high pressure. Although these rough phenomena have been confirmed by the image obtained by a high-speed camera, the details with regard to the quantity and distribution of the metal jet has been indistinct. Therefore the metal block was put on the central axis and the metal jet that collided with it was observed. The optimal condition that the metal jet is discharged was confirmed.
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