巻号一覧
57 巻, 5 号
May
選択された号の論文の16件中1～16を表示しています
- |<
- <
- 1
- >
- >|
研究
研究
-
清水 透, 松崎 邦男, 菊地 薫, 金武 直幸2010 年 57 巻 5 号 p. 277-283
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスSeveral methods have been developed for producing high-porosity open-cell metal foams, but no method is available for producing closed-cell type metal foams with a porosity of more than 95 %. We therefore developed a novel process for producing a high-porosity closed-cell metal foam using a hydro-gel binder. This process is gelled a slurry which contains a metal powder, an aqueous polymer solution and a foaming agent. When the gelled slurry is heated, the foaming agent causes it to foam; this develops the proper conditions for generating a closed-cell structure. We applied this method to making stainless steel foams and obtained metal foams with porosities of more than 98 %. This method is not only used for to producing metal foams, but could be applied in producing ceramics foams.抄録全体を表示PDF形式でダウンロード (1932K) -
清水 透, 松崎 邦男, 菊地 薫, 金武 直幸2010 年 57 巻 5 号 p. 284-290
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスProduction process of high porosity closed cell type metal foam is developed using a hydrogel binder. Using this process, the stainless steel foam is produced with its porosity more than 98 %. However, we need to use fine metal powder to produce high porosity metal foam, and as the result, the production cost of the foam is increased. Therefore, the metal foams are produced using different grain size powders and their foam properties are compared with each other. As the result, finer powders should be used for producing high porosity metal foam. However, relatively coarse powder can be used for producing 95 % porosity metal foam, decreasing the production cost of the foam. This cost reduction can expand the applications of this material.抄録全体を表示PDF形式でダウンロード (849K)
特集：傾斜機能・生体材料
総報
-
後藤 孝2010 年 57 巻 5 号 p. 292
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスPDF形式でダウンロード (141K)
総説
-
Mitsugu Todo2010 年 57 巻 5 号 p. 293-297
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスIn this paper, mechanical studies on biomaterials for reconstruction and regeneration of bone and joints of lower limb are summarized. Finite element analyses of knee and hip prostheses were performed to characterize the mechanical conditions of the artificial components and the mechanical interaction between bone and prosthesis. The computational results showed that for the knee prosthesis, the transitional behavior of stress concentration on ultra-high molecular weight polyethylene insert corresponded to actual damage formations, and for the hip prosthesis, the disturbed stress on the injured acetabulum was effectively reduced by the joint replacement, however, stress shielding effect in the femur was also induced by stem insertion. Strength enhancement of bioabsorbable porous poly(L-lactide) scaffold was also investigated using layered structurization. It was found that those properties were effectively improved by introducing layered structures.抄録全体を表示PDF形式でダウンロード (901K)
研究
-
Li-Mei Ren, Wen-Xue Wang, Yoshihiro Takao, Zhao-Xiang Chen2010 年 57 巻 5 号 p. 298-305
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスIn this work the mechanical response of tooth supporting structure to the occlusal load was analyzed by means of finite element analysis. The attribution of the cementum-dentine junction (CDJ) and cementum to the stress distribution was investigated. Models of block-shape mandible included a premolar with/without cementum-dentine junction (CDJ) and cementums in the supporting structures were constructed. For each case, a load of 50 N was applied to the crown at a 45-degree angle to the long axis of the tooth. The present finite element analyses indicated that incorporation of CDJ and cementum resulted in decreases in the stress levels. These two tissues are important in absorbing and distributing stress thus they should be considered in analyzing the load transfer characteristics within the tooth supporting structure. In addition, this study proved that it is feasible to simplify the finite element model by employing the modified Young's modulus of PDL to realize the function of CDJ. Moreover, an attempt to correlate the results of the current study with the dental implant designing was made.抄録全体を表示PDF形式でダウンロード (1476K) -
Zhao-Xiang Chen, Wen-Xue Wang, Yoshihiro Takao, Terutake Matsubara, Li ...2010 年 57 巻 5 号 p. 306-313
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスTiO2 layer was fabricated on commercially pure titanium using an anodic spark oxidation technique with 1M phosphoric acid solution. Subsequent heat or water treatment was performed to improve the biocompatibility of oxide layers. Surface characteristics of oxide layers before and after subsequent treatments and their influence on the cell response were investigated. It was found that the oxide layer without subsequent treatments exhibited a porous surface structure with few nanometer features. Thin film X-ray diffraction analysis and electron probe microanalysis indicated that the oxide layer consisted of amorphous or poorly crystallized oxides with the incorporation of phosphorus. After heat treatment (500°C, 3 h), the crystallinity degree of oxide layer increased, but only slight change in the surface morphology was observed. In contrast, water treatment (80°C, 48 h) not only can significantly transform the amorphous oxides into crystalline anatase, but also result in a nanostructured surface. In vitro biocompatibility study of oxide layers demonstrated better cell response to water treated oxide layer than untreated one.抄録全体を表示PDF形式でダウンロード (1138K) -
上田 恭介, 川崎 雄城, 後藤 孝, 栗原 淳, 川村 仁, 成島 尚之2010 年 57 巻 5 号 p. 314-320
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスDouble-layered calcium phosphate coating films consisting of layers with different crystallinity and composition were fabricated on titanium substrates by RF magnetron sputtering. The first layer of the double-layered coating film, i.e., the inner layer, was made of calcium phosphate having high crystallinity, the second layer, i.e., the outer layer, was made of calcium phosphate having low crystallinity. A double-layered HAp/OAp coating film was fabricated on the titanium substrate; as an inner layer, an HAp film was prepared on the titanium substrate by heat treatment of an OAp film in air at 873 K for 7.2 ks, and then, the HAp layer was coated with the OAp film. In the fabrication of a double-layered OAp/ACP coating film, the inner OAp and the outer ACP films were coated on the titanium substrate under different sputtering conditions. The thickness of the single layer was controlled to be 0.5 μm, and the total thickness of these double-layered coating films was around 1 μm. The coating film that comprises the double-layer was dense with a uniform thickness, and the two layers were in close contact with each other. The bonding strength of the HAp/OAp coating film was greater than 50 MPa. As in vivo evaluation, the removal torque of HAp/OAp-coated titanium implants from the femur of Japanese white rabbits was measured. The value of this torque was considerably higher than that of the removal torque of non-coated titanium implants. The outer OAp layer with low crystallinity appeared to dissolve after the 4-week implantation, while the inner HAp layer remained intact and was directly attached to the new bone.抄録全体を表示PDF形式でダウンロード (1407K)
解説
-
渡辺 義見, 三浦 永理, 佐藤 尚2010 年 57 巻 5 号 p. 321-326
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスFunctionally graded materials (FGMs) are a new class of materials whose compositions change from one surface to another surface. FGMs can be fabricated under a centrifugal force. Fabrication methods of FGMs under the centrifugal force are classified into three categories, namely centrifugal method (application of centrifugal casting), centrifugal slurry method and centrifugal pressurization method (simple pressurization by the centrifugal force). We are developing a centrifugal slurry-pouring method and centrifugal mixed-powder method, which are classified into the latter two categories, and they are combination of centrifugal method and powder metallurgy. In this article, some recent results from the centrifugal slurry-pouring method and centrifugal mixed-powder method will be described.抄録全体を表示PDF形式でダウンロード (1283K)
研究
-
大野 卓哉, 久保田 正広2010 年 57 巻 5 号 p. 327-332
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスPure titanium powder was mechanically milled (MMed) using a vibrational ball mill with stearic acid. The MMed powders were consolidated by spark plasma sintering (SPS). Two sintering conditions were selected in order to understand the effect of the spark plasma sintering time on mechanical properties of bulk pure titanium. The mechanical properties and microstructures of SPS materials sintered at 1073 K for 180 s with the heating rate of 1.67 K/s and at 1073 K for 1.8 ks with the heating rate of 1 K/s were compared. The SPS materials produced by two different sintering conditions exhibited almost the same hardness and similar microstructure. Near-full density was achieved for the SPS materials for 180 s under an applied pressure of 49 MPa at a temperature of 1073 K. Formation of TiC by solid-state reaction was observed for the SPS materials consolidated from 4 and 8 h MMed powders. A maximum Vickers hardness of 933 HV obtained for the SPSed material fabricated from 4 h MMed powder with 0.50 g of PCA.抄録全体を表示PDF形式でダウンロード (1493K) -
大尾 守, 長谷崎 和洋, 篠田 龍一, 及川 隆仁, 吉岡 一郎2010 年 57 巻 5 号 p. 333-337
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスFly ash/NiCr alloy functionally graded materials (FGMs) of φ 100 mm plate were prepared by spark plasma sintering (SPS). FGMs of simple stacking structure (fly ash/NiCr) and sandwich stacking structure (NiCr/fly ash/NiCr, fly ash/NiCr/fly ash) 3 to 4 mm in thickness were prepared. The deformation of simple stacked sample was caused by thermal expansion differences. The cross-section and elemental profiles of simple stacked sample were studied by scanning electron microscopy (SEM) and electron probe microanalysis (EPMA), respectively. The sandwich stacked sample of fly ash/NiCr=(100/0, 60/40, 40/60, 60/40, 100/0) had a flat shape and free of the surface crack.抄録全体を表示PDF形式でダウンロード (1175K)
特集：粉末製造技術とその応用
総報
-
中村 尚道2010 年 57 巻 5 号 p. 340
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスPDF形式でダウンロード (159K)
受賞記念講演
-
宇波 繁, 尾崎 由紀子, 後迫 勉, 谷野 仁2010 年 57 巻 5 号 p. 341-347
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスA new molybdenum hybrid-alloyed steel powder has been developed. This powder gives sintered parts with improved fatigue strength by a conventional belt furnace sintering. The powder is based on a molybdenum prealloyed steel powder to which molybdenum powder particles have been diffusion bonded. The sintered compact made of the developed powder has a finer pore structure than that of the conventional molybdenum prealloyed steel powder, because the ferritic iron phase (α-iron phase) with a high diffusion coefficient is formed in the sintering necks where molybdenum is concentrated resulting in enhanced sintering.
This developed powder has already been applied as a raw material of a high strength part for automotive engines with advantages of sintering cost, productivity improvement and enhanced flexibility in manufacturing process. This powder also gives an advantage over the conventional diffusion-alloyed steel powder in terms of raw material cost reduction.抄録全体を表示PDF形式でダウンロード (1587K)
研究
-
山下 洋子, 原田 智洋, 牧野 晃久, 藤吉 国孝, 上野 修司, 古賀 三井2010 年 57 巻 5 号 p. 348-351
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスHigh purity and nano-sized tungsten carbide (WC) particles have been successfully prepared using chemical complex solution which is composed of tungstic acid, citric acid and ammonia solution. The precursor, which was obtained by drying the chemical complex solution, was heated to 1423 K under Ar atmosphere. Total carbon (C) amount of the heat-treated precursor was controlled by molar ratio of citric acid and tungstic acid. In case of this experimental system, W-C bonds have been already formed at 723 K. The carbonization temperature was lower than that of the conventional methods that used C and WO3 or W, therefore particle growth has been suppressed. The sizes of the obtained WC particles were under 100 nm and the amounts of iron and cobalt as impurities were under 10 ppm.抄録全体を表示PDF形式でダウンロード (563K) -
三浦 秀士, 篠崎 亮平, Shinta Virdhian, 長田 稔子2010 年 57 巻 5 号 p. 352-356
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスTitanium and it's alloys have been widely used for aerospace applications because of their excellent attributes of light weight, high strength, heat resistance and corrosion resistance material. However, it is not easy to produce the complicate shaped parts due to the poor castability and machinability. Metal Injection Molding (MIM) technique is expected to be one of useful advanced powder processing route as complicated shape forming for titanium and it's alloy powders. The purpose of this study is to produce the large Ti alloy products by MIM process. MIM process condition is the most important to control the quality of final products. Five different disk specimens with difference sizes of diameter and thickness are prepared, and the effect of debinding and sintering conditions on the deformation of compacts are investigated. In this paper, the evaluation of the deformation was established by using a non-contact laser displacement measuring equipment.抄録全体を表示PDF形式でダウンロード (1220K)
研究速報
-
中山 博行, 尾崎 公洋, 田中 宏靖, 小林 慶三2010 年 57 巻 5 号 p. 357-360
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスThe Fe-Sm binary alloy ribbons were prepared by melt spinning technique. The prepared alloys with Sm 8.7 and 12.7 at% were mainly composed of TbCu7 metastable phase. In addition, α-Fe in Sm 8.7 at% and Fe2Sm in Sm 12.7 at% alloy were also observed. In contrast to them, the alloy with Sm 27.5 at% has an amorphous phase. After mechanical grinding (MG) for 72 ks under N2 atmosphere, the alloys with Sm 8.7 and 12.7 at% showed the phase transition to the metastable state coexisting of α-Fe and Fe-Sm amorphous phase. On the other hand, the alloy with Sm 27.5 at% showed the crystallization after the MG from amorphous phase to Fe-Sm-O phase. The MGed alloys with Sm 8.7 and 12.7 at% were heated up to 1027 K. After the heating, the alloy with Sm 8.7 at% was composed of α-Fe, FeN, Fe-Sm-N and Fe3O4. On the other hand, the metastable phase was still sustained in the alloy with Sm 12.7 at%.抄録全体を表示PDF形式でダウンロード (536K)
本会記事
-
2010 年 57 巻 5 号 p. Pref5_1
発行日: 2010年
公開日: 2010/07/22
ジャーナル オープンアクセスPDF形式でダウンロード (75K)
- |<
- <
- 1
- >
- >|