巻号一覧
52 巻, 1 号
January
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研究
研究
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大久保 貴広, 西山 勝廣, 小野 哲央, 丹羽 進, 河野 通, 酒井 秀樹, 小石 真純, 阿部 正彦2005 年 52 巻 1 号 p. 3-9
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスFine particles of TiB2 were prepared by metallothermic reduction (MTR) of TiO2 with Mg or MgO, where we examined the synthesis conditions to obtain smaller fine particles. As a result, we found that theory of function-building fine particle preparation could be applied to synthesize nano-atomized fine particles of TiB2. The temperature of MTR process also decreased with reducing particle size of TiO2. When TiO2 of ST-01, of which particle size is the smallest in our study, was used as a source of titanium and treated at 550°C, the smallest particles of TiB2 were obtained.抄録全体を表示PDF形式でダウンロード (2315K) -
吉岡 恒太郎, 安達 元洋, Petrykin Valery, 垣花 眞人2005 年 52 巻 1 号 p. 10-15
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスConventional usage of TaCl5 in the polymerizable complex (PC) method results in the corrosion of experimental equipment and degradation of functional properties of the obtained materials due to the residual chloride. In this report ammonium and guanidine salts of tantalum-citric acid complex were used as soluble tantalum compounds. Four tantalum containing complex oxides (NaTaO3, SrTa2O6, Sr2Ta2O7 and Sr5Ta4O15) were successfully synthesized by PC method using these chloride-free precursors.抄録全体を表示PDF形式でダウンロード (828K) -
Kaduichi Kitagawa, Takashi Yamamoto, Kazuo Kitagawa2005 年 52 巻 1 号 p. 16-21
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスIn this study, two types of PZT (lead zirconate titanate, Pb(Zr,Ti)O3) ceramics were used. One is low-Qm PZT, mainly used as signal devices. The other is high-Qm PZT, which is utilized high power conditions applied in piezoelectric transformers, actuators and ultrasonic motors. The Qm is a mechanical quality factor (Qm = s'/s”, s* = s'-js”, where s* is an elastic compliance). In order to obtain a high output power, PZT ceramics must be driven at a high vibration level. This causes heat generation. Recently, the demand of high-Qm PZT is increased. Because, the high-Qm PZT is utilized under the condition of continually stretch and shrink, to avoid premature failure, the high-strength piezoelectric ceramics is required. The mechanical properties including fatigue of Pb(Zr,Ti)O3(PZT) ceramics were investigated in this study.
The bending strength, Young's modulus and Vicker's hardness of high-Qm PZT were higher than those of low-Qm ones. It was found that by the fatigue test, as the applied stress of high-Qm PZT increased, the number of cycles to fracture decreased remarkably, compared with that of low-Qm ones. The SEM fractographs of fatigued high-Qm specimens indicated that inter-granular fracture occured preferentially. The difference of these mechanical properties and fatigue behavior between low-Qm and high-Qm depended on the inter-granular fatigue crack which proceeded along the grain boundary in high-Qm material.抄録全体を表示PDF形式でダウンロード (1353K) -
桜井 法昭, 武川 淳二郎2005 年 52 巻 1 号 p. 22-27
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスIn order to fabricate the NiTi foams with porosity over 80%, the vacuum process using of slurry was applied. The mixture of Ni and Ti elemental powders was dipped into the solution of 7.5 mass% polyvinyl alcohol, and stirred to make slurry. The lightly compacted lumps of slurry were subjected to diminished atmospheric pressure to make foamed compacts. The green foams were debound and sintered in vacuum into NiTi sintered foams with 85% porosity. X-ray analysis showed alloying of NiTi was completed by the sintering at above 1100°C. X-ray diffraction analysis and DSC measurement also indicated that the NiTi foams consisted of B2 austenite and B19' martensite phases. From the measurement of shape recovery strain, NiTi foams obtained from this process showed the far excellent shape recovery characteristics compared with those of NiTi bulk materials.抄録全体を表示PDF形式でダウンロード (986K) -
藤川 隆男, 真鍋 康夫, 染谷 慎一2005 年 52 巻 1 号 p. 28-34
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスCoral sand (coral fossil sand), the main ingredient of which is calcium carbonate, is a kind of naturally found materials in the bottom of the sea near the coral islands like Okinawa. While marbles derived from coral sand as a metamorphic rock are produced in Taiwan. Producing marbles artificially by sintering has been very difficult, because calcium carbonate decomposes at high temperatures and changes to calcium oxide, generating gaseous carbon dioxide. The only method which can consolidate calcium carbonate powder has been the encapsulation HIP method in which a green powder body is encapsulated in a metal can and subjected to a high pressure and high temperature condition. This method, however, is not practical to be utilized for commercial production, because the encapsulation technology requires a lot of skill, expensive materials and equipment. In this study, the possibility of full densification of calcium carbonate powder by capsule-free HIP'ing without capsule was investigated by using a coral sand powder as a sample material. And further the mechanical properties of the obtained dense sintered compact were evaluated for the application to tiles.抄録全体を表示PDF形式でダウンロード (1907K) -
荻沼 秀樹, 湯浅 栄二2005 年 52 巻 1 号 p. 35-40
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスAtomized aluminum powder mixed to magnesium alloy (AZ31) turning chips with Mg-12 and 40 mol% Al compositions, were mechanically alloyed (MA) for 54 ks. For the surface improvements of the magnesium alloy, the obtained MA powders of Mg-12 mol% Al (12AlMA) and Mg-40 mol% Al (40AlMA) were stacked on magnesium alloy (AZ31 and AM60) sheets, then hot-rolled at various temperatures. After the roll-bonding, Mg17Al12 phase precipitates from super-saturated α-Mg in 12AlMA powder and it also forms from amorphous phases in 40AlMA powder. The hardness in the bonded MA powder layer becomes higher than as-MA powder particles. When roll-bonding were performed for 12AlMA powder over 400 K and for 40AlMA powder over 480 K, Mg and Al mixed each other by diffusion phenomenon in interface of MA layer and Mg alloy sheet. Fracture strength in 3-point bending of magnesium alloy sheet increases by bonding of MA powder.抄録全体を表示PDF形式でダウンロード (1311K)
特集 PIM及び粉末の各種成形と周辺技術
総報
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三浦 秀士2005 年 52 巻 1 号 p. 42
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスPDF形式でダウンロード (132K)
研究
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伊藤 芳典, 針幸 達也, 佐藤 憲治, 三浦 秀士2005 年 52 巻 1 号 p. 43-48
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスThe metal injection molding process was applied to produce a near-alpha titanium alloy using a mixture of Ti and pre-alloyed powders, and that of elemental powders. The effect of sintering conditions on the mechanical properties and microstructures of the sintered compacts were investigated. To estimate the alloying of each element, characteristic X-ray images were also measured by means of electron probe micro analyzer.
The sintered compacts using a mixture of Ti and pre-alloyed powders showed higher density and mechanical properties as compared to the compacts using a mixture of elemental powders. The former sintered at about 1323 K for 14.4 ks showed a sufficient alloying of each element, but the latter, even sintered at about 1473 K for 14.4 ks, showed an insufficient alloying of molybdenum which was hardest diffusion element in this titanium alloy. Eventually, the mechanical properties of the compacts using a mixture of Ti and pre-alloyed powders were comparable to those of the wrought alloys.抄録全体を表示PDF形式でダウンロード (2138K)
研究速報
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大塚 淳, 武川 淳二郎2005 年 52 巻 1 号 p. 49-54
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスIt has been known that boron (B) is a very effective sintering enhancer for SKH51 steel powder. However, there were a problem that the enhancing effect of B was limited only when the SKH51 powder compacts were sintered in H2 atmosphere, where the hardness of the compacts was reduced due to the decarburization. In this study, we tried to obtain the sintered PIM SKH51 compacts with high densities and mechanical strengths by adding 0.2 mass% Al2O3 powder together with 0.4 mass% B powder to the SKH51 steel powder. The powder mixture was compacted by injection molded and sintered at 1448 K∼1493 K for 3 h in H2. It was shown that the PIM SKH51 steel compacts with Al2O3 and B powder were appreciably densified during sintering, compared with the compacts containing B powder, and the nearly theoretical density was obtained when they were sintered at 1458 K. Although the tensile strength of the sintered PIM compacts with Al2O3 and B powders slightly lowered compared with those containing B powder, the hardness of the PIM compacts was greatly improved by the addition of Al2O3 powder together with B. The hardness of the PIM compacts with Al2O3 and B reached to the values over Hv=1000.抄録全体を表示PDF形式でダウンロード (1852K) -
松崎 覚, 田中 茂雄, 西籔 和明2005 年 52 巻 1 号 p. 55-59
発行日: 2005年
公開日: 2006/04/28
ジャーナル オープンアクセスThis study aims to investigate the possibility for producing micro metal structured parts by applying micro metal injection molding (μ-MIM), the insert μ-MIM methods based on LIGA process were proposed, which used two types of sacrificial molds for MIM processing as following; 1) PMMA (polymethylmethacrylate) resist and 2) PMMA mold injected in Ni electroformed mold. These processes were named “LIGA/μ-iMIM method” and the feasibility was checked by using SUS316L stainless steel powders. It was demonstrated that this method had a great potential to produce micro metal structured parts, also confirmed that the finer metal powders were better for their transcription than the coarse one.抄録全体を表示PDF形式でダウンロード (1403K)
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