著者

渋谷 明信 澁谷 泰蔵 眞子 隆志

出版者

一般社団法人 粉体粉末冶金協会

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.65, no.6, pp.335-341, 2018-06-15 (Released:2018-06-28)

参考文献数

27

---

R3Al5O12 (R: rare-earth) ceramics are one of the emitter candidates for thermophotovoltaic (TPV) systems. We conducted a detailed study on the fabrication, the microstructural characterization, and the thermal emissive performance of porous Yb3Al5O12 (YbAG) emitters. The emitters were synthesized by solid-state reaction and sintered with various conditions using ball-milling powders, which result in different porosities of the samples. Thermal radiation measurements revealed that the porous ceramics had excellent selectivity regarding emission wavelengths and optimal porosity of sintered bodies for emittance wavelengths selectivity are different according to grain size of powders related to sintered body grain size. Generally, in spite of the narrow-band thermal emissions of rare-earth ions, most ceramics do not present sufficient selectivity because of their transparency in the near infrared range. This paper discusses the mechanism of high selectivity from observations of the microstructures of developed YbAG ceramics.

著者

内田 有紀子 大石 響子 中西 真 藤井 達生 高田 潤 草野 圭弘 菊池 丈幸

出版者

一般社団法人 粉体粉末冶金協会

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.52, no.8, pp.640-645, 2005

被引用文献数

2 2

---

We have successfully prepared Carbon/Fe-Co alloy composites starting from metal organic precursors synthesized by polymerized complex method. The carbon/Fe-Co alloy composites were obtained after the carbonization of the precursors heat-treated at ambient pressure and lower temperatures ranging from 500 to 700°C in N₂ gas flow. Crystalline sizes of both carbon matrix and Fe-Co alloy particles were determined by X-ray diffraction measurements as a function of the Co concentration and the carbonized temperature. The alloy particles were widely dispersed in the carbon matrix and the particle size carbonized at 600°C was about 20∼50 nm observed by scanning electron microscopy. The composite carbonized at 600°C had very small coercivity of 14 Oe and exhibited relatively large permeability spectra at frequency of GHz range.

著者

平野 眞一 田島 伸

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.37, no.3, pp.421-425, 1990-04-25 (Released:2009-05-22)

参考文献数

12

被引用文献数

3 2

---

The formation process and magnetic properties of Fe3C particles were investigated. Various iron oxides as a starting material were carbureted with CO gas in a furnace. Fe3C was formed at the reaction temperatures from 450 to 600°C. The partial pressure of CO gas was controlled by mixing with N2 gas to prevent the free carbon deposition due to the disproportionation of CO gas. Synthesized Fe3C particles were identified as a single phase by XRD and the weight change measurement. The saturation magnetization of Fe3C increased from 80 to 117 emu/g with the increase of the reaction temperature, while the coercive force decreased from 170 to 80 Oe with the increase of the reaction temperature.

著者

萩原 正 堀場 欣紀 佐々 雅祥 中野 禅 清水 透 松崎 邦男 佐藤 直子

出版者

一般社団法人 粉体粉末冶金協会

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.61, no.5, pp.223-226, 2014

被引用文献数

2

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Aspect Inc. and AIST (National Institute of Advanced Industrial Science and Technology), as a member of ALPROT, which stands for Advanced Laser and Process Technology Research Association, have developed two types of unprecedented Selective Laser Melting platform with a high vacuum built process chamber and a new developed QCW (quasi continuous wave) laser system in the national project, which started from 2010 and conducted by NEDO (New Energy and Industrial Technology Development Organization). In this report, the development status of the Selective Laser Melting platform is mainly introduced.

著者

高岡 勝哉 村瀬 康 加藤 将樹 廣田 健

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.57, no.2, pp.112-117, 2010-02-15

被引用文献数

1 1

---

Synthesis of dense composite materials with the compositions of Al<SUB>2</SUB>O<SUB>3</SUB>/Mo<SUB>2</SUB>N=100/0∼40/60 vol% has been attempted directly from Al<SUB>2</SUB>O<SUB>3</SUB>/Mo mixed raw powder compacts using capsule-free N<SUB>2</SUB> hot isostatic pressing (HIP). During HIPing [1500°C/(16∼20-200MPa)/1h], solid/gas reaction between Mo and N<SUB>2</SUB> was introduced to form Mo<SUB>2</SUB>N. The most of sintered composites consisting of only Al<SUB>2</SUB>O<SUB>3</SUB> and Mo<SUB>2</SUB>N phases reached to a higher relative density than 98.0 % with closed pores nevertheless capsule-free HIPing. Dispersion of Mo<SUB>2</SUB>N particles just formed suppressed the grain growth of Al<SUB>2</SUB>O<SUB>3</SUB> during sintering. Mechanical properties, such as bending strength (<I>σ</I><SUB>b</SUB>), Vickers hardness (<I>H</I><SUB>V</SUB>), fracture toughness (<I>K</I><SUB>1C</SUB>), and other properties have been evaluated as a function of their compositions. The best mechanical values of <I>σ</I><SUB>b</SUB> (∼573 MPa), <I>H</I><SUB>V</SUB> (∼20.3 GPa) and <I>K</I><SUB>1C</SUB> (∼5.00 MPa·m<SUP>1/2</SUP>) were attained at the composition of Al<SUB>2</SUB>O<SUB>3</SUB>/Mo<SUB>2</SUB>N=90/10 vol%, due to a high density (98.6 %) and small grain size of Al<SUB>2</SUB>O<SUB>3</SUB> matrix (<I>G</I><SUB>s</SUB>∼4.70 <I>μ</I>m). Further addition of Mo<SUB>2</SUB>N reduced the sinterability of matrix grains, resulting in low densities of around 90 % at the 40/60 vol% composition.

著者

Baolong Shen Akihisa Inoue

出版者

一般社団法人 粉体粉末冶金協会

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.58, no.6, pp.403, 2011 (Released:2011-07-15)

被引用文献数

1 1

---

掲載論文の取り消しについて「粉体および粉末冶金」編集委員会, 委員長 吉村 一良「粉体および粉末冶金」Vol.50, No.9に掲載の下記論文1について,先に投稿された下記論文2の内容と著しく重複していることが判明しました.「粉体および粉末冶金」編集委員会では,本件に関し,粉体および粉末冶金投稿規程及び研究倫理上の理由によって,当該論文の掲載を取り消すことにいたしました.この処置は,論文1が論文2の審査中に投稿されたものであり,また論文1中に論文2の引用もなかったため,論文内容の重複について審査段階で認識することができなかったための処置であります.○論文1:Fe-Based Glassy Magnetic Cores Prepared by Spark Plasma Sintering Glassy Alloy Powders, Baolong Shen and Akihisa Inoue,粉体および粉末冶金, Vol.50, No.9 (2003) 680-686. ( Received May 2, 2003 ) ○論文2:Fabrication of large-size Fe-based glassy cores with good soft magnetic properties by spark plasma sintering, Baolong Shen and A. Inoue, Journal of Materials Research, Vol.18, No.9 (2003) 2115-2121. ( Received 27 April, 2003, accepted 10 June, 2003 ).

著者

桃沢 愛 且井 宏和 伊藤 暁彦 後藤 孝

出版者

一般社団法人 粉体粉末冶金協会

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.63, no.3, pp.128-131, 2016-03-15 (Released:2016-04-09)

参考文献数

8

被引用文献数

2

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TiO2 is widely used in dental materials as orthopedic and dental implant thanks to its good properties and biocompatibility. Rutile- and anatase-type TiO2 films were prepared by laser chemical vapor deposition using Nd:YAG laser. The TiO2 films showed cauliflower like microstructures at laser power of 160 W. The highest deposition rate was 17.1 μm/h at the total pressure of 800 Pa. Rutile- and anatase-type TiO2 was formed at the total pressure of 210 Pa, anatase-type at 800 Pa and rutile-type at 1500 Pa. The degree of osseointegration in the early stages is critical for determining the mechanical stability of the implant. The cell attachment behaviors of TiO2 films, in particular, the cell density and aspect ratio of osteoblast cells on TiO2 films were evaluated. Microstructure of the surface and photocatalytic performance of anatase-type TiO2 may be effective for cell attachment.

著者

岡 英夫

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.42, no.4, pp.544-547, 1995-04-15 (Released:2009-05-22)

参考文献数

7

---

The magnetic agar, which was previously reported by the author, has several problems such as low permeability and complicated manufacturing process. The purpose of this study is to report a simple manufacturing process of the magnetic agar, by selecting magnetic powder of high permeability. Measurements show the mixing limits of magnetic powder and powder agar.

著者

後藤 公美

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.36, no.6, pp.761-769, 1989-08-25 (Released:2009-12-04)

参考文献数

24

被引用文献数

2 3

---

Small particles of ferromagnetic BaO⋅Fe2O3, SmCo5, SM2Co17 and Nd2Fe14B compounds were prepared by the circumspect powder metallurgical method, and behaviours of their magnetic domains were studied with the decrease of the particle size.The colloid-SEM method invented by the present author was effectively used to observe domains of small particles less than 10 μm in size. With the decrease of the particle size the number of domains in one particle decreases, and finally the single-domain state is found for each compound, as expected by the theories. The critical size for single-domain particles, which is defined by the upper limit of the particle size range where the single-domain state can exist, is successfully estimated for all the above compounds from the particle size distribution curve of many single-domain particles, and obtained values of the critical sizes of the compounds are compared with the theoretical ones.

著者

中村 龍哉 松井 裕樹 山田 義博 田渕 光春 小林 陽

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.57, no.11, pp.725-728, 2010-11-15

参考文献数

17

---

Cathode using the olivine particles was subjected to an open-circuit voltage measurement under the relaxation condition of 24 h at each SOC and DOD states. The electrochemical reaction in the LiFePO<SUB>4</SUB> cathode was composed of a large plateau around 3.45 V with sloped regions nearby for both the fully charged and discharged states. It was found that the potential profile in the sloped regions exhibited a hysteresis. Furthermore, both sloped regions became narrower when the operating temperature was raised from 30 to 60°C. Furthermore, it was found that the apparent diffusion coefficient of Li<SUP>+</SUP> ions in the sloped regions was much smaller than that in the plateau region. These facts implied that the obtained profiles were not in an equilibrium state with a quasi-OCV profile than the real one, and that the potential relaxation in the sloped regions took an extremely long time.

著者

河波 利夫

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.39, no.12, pp.1060-1066, 1992

被引用文献数

2 2

---

Development of toughened zirconia parts for grinding was reviewed. This work was achieved by developing the high purity, ultra-fine zirconia powder processing and toughened Y-TZP( Y<SUB>2</SUB>O<SUB>3</SUB> doped tetragonal ZrO<SUB>2</SUB> ceramics ), and investigating the propertieswear characteristics relation. Zirconia powders prepared by the hydrolysis method, which was the lowest production cost, showed the good formability and sinterbility. Y-TZPP containing 2.5-3.0mol% Y<SUB>2</SUB>O<SUB>3</SUB> gave higher fracture toughness and strength by the stress induced phase transformation toughening. The wear characteristics of Y-TZP grinding media depended strongly on the fracture toughness, strength and grain size, but not on hardness and density within the range of this experiment. It is considered that the excellent wear characteristic zirconia parts for grinding can be obtained by controlling the fracture toughness, strength and microstructure. To investigate these mechanism, the microstructures of worn areas were examined by SEM observations.

著者

井上 誠 東 泰助 小野木 伯薫 横田 勝 村田 安規 中平 敦

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.58, no.7, pp.407-411, 2011-07-15

参考文献数

8

---

We have developed the Ag-Cu-Sn-Ni quaternary brazing filler metal having a low melting point, a high strength and a high ductility. Then, we produced wire saws composed of Ni-coated SUS304 wires, on which diamond abrasives are fixed with this brazing filler metal. We tried to slice the Si ingots using this wire saw. Good results were obtained for the application to the production of silicon wafers for solar cells. Accordingly, we focused on the basic experiments for further performance of the fixed abrasive diamond wire saws, leading to low cost of slicing technique of hard materials such as silicon and sapphire. In particular, we examined wettability, interfacial reaction and joint strength between Ag-Cu-Sn-Ni quaternary brazing filler metal and industrial metal plates such as Cu, Ni or flux coated SUS304.

著者

島 裕也 中村 龍哉 松井 裕樹 山田 義博 宮内 啓成 橋本 聡司 阿部 一雄

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.57, no.11, pp.729-733, 2010-11-15

参考文献数

13

被引用文献数

1

---

LiFePO<SUB>4</SUB>/C composite particles were prepared by gas-solid phase reaction. The reaction temperature had a detrimental effect on the purity of the composite particles. The suitable temperature was around 650°C, above and below which ferromagnetic impurities were found. The retention time influenced only the carbon deposition amount, but the excess amount of carbon caused the degradation of the electrochemical performance. The specimen prepared at the optimum conditions exhibited superior performances in both rate capability and cycle stability as well as less impedance growth during the cycling.

著者

有川 峯幸

出版者

一般社団法人 粉体粉末冶金協会

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.52, no.2, pp.109-114, 2005 (Released:2006-04-28)

参考文献数

10

---

Recently Nano-technology is one of the most popular topics, and Nano Carbon material is said to be the technology that is the nearest to the business. Both Fullerene that is the cage shape carbon molecular, and Carbon Nano Tube that is the tube shape of carbon structure, have already reached to the industrial stage. In this overview, the latest development and information about Fullerene production and application are explained.

著者

和田 任弘 岩本 晃二 尾崎 充紀 廣 和樹

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.58, no.5, pp.275-278, 2011-05-15

---

When tapping carbon steel with a straight fluted taper pipe tap for NPT threads, the cutting section is often prone to fracture on the thread part because of the increase in chip thickness, which causes the chip to jam as the tapping process proceeds. When tapping carbon steel with a high speed steel tap (HISS tap), this adversely affects the tapping operation due to the low cutting speed. Increasing the cutting speed is effective to ensure a highly efficient tapping operation.<BR>In this study, a tapping test was conducted on a Cr-Mo steel SCM435 using various kinds of surface treated HISS tap, namely untreated taps (HISS tap), oxide treated taps, TiN coated taps, TiCN coated taps and AlCrN coated taps, to determine the effective tool material for high efficiency tapping. The main results obtained are as follows: (1) The higher cutting speed was determined to be effective in preventing fracture of the cutting part on the thread part of the tap because the chip formed both a slimmer and spiral shape when tapping at high cutting speed. (2) The AlCrN coated HISS tap showed the best wear resistance. (3) The AlCrN film had both a lower friction coefficient and higher hardness compared with the TiN or TiCN film.

著者

鈴木 福二 福島 正二

出版者

一般社団法人 粉体粉末冶金協会

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.28, no.7, pp.239-244, 1981-10-25 (Released:2009-05-22)

参考文献数

2

被引用文献数

2

出版者

一般社団法人 粉体粉末冶金協会

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.63, no.4, pp.239-248, 2016-04-15 (Released:2016-05-07)

著者

松田 光弘 三浦 秀士

出版者

Japan Society of Powder and Powder Metallurgy

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.47, no.6, pp.681-685, 2000-06-15

被引用文献数

3 7

---

In our previous studies on the 4600 steels produced by Metal Injection Molding (MIM) process using mixed elemental powder, the fine heterogeneous microstructure caused by the agglomeration of Ni powders was reported to be significantly effective for the improvement of mechanical properties. This study has been performed to clarify and optimize the relationship between the mechanical properties and the heterogeneous microstructure for ultrahigh strengthening the sintered low alloy steels (4600grade, 0.4 mass%C) produced by MIM process varying Ni content from 0 to 8 mass%.<BR>The tensile and fatigue strength were improved significantly with increasing Ni content to 6mass%, without loss of the ductility. This seemed to be due to the solution strengthening and the mezzo-heterogeneous microstructure which were consisted of Ni rich martensite surrounded by a network of tempered martensite. However, the tensile and fatigue strength of the steel added 8 mass% Ni were dropped by the increase of retained austenite.

著者

神山 新一

出版者

一般社団法人粉体粉末冶金協会

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.43, no.6, pp.751-756, 1996-06-15 (Released:2009-05-22)

参考文献数

31

---

A recent development in magnetic fluids research is reviewed. The research activities in this field are increasing accompanied with the success of the synthesis of magnetic fluids with excellent magnetic properties. Apparent viscosity and rheological properties are discussed in connection with the particle aggregates in the applied magnetic field. As the thermo-fluid dynamics of magnetic fluids, recent investigations on the pipe flow problems and heat transfer control are taken up. Finally, as the representative examples of recent studies on the applications of magnetic fluids, various sensors, actuators, grinding device and heat pipe are explained.

著者

杉本 諭 籠谷 登志夫 前田 徹

出版者

一般社団法人 粉体粉末冶金協会

雑誌

粉体および粉末冶金 (ISSN:05328799)

巻号頁・発行日

vol.53, no.3, pp.251-257, 2006 (Released:2006-08-18)

参考文献数

16

被引用文献数

1 2

---

Recently, the use of microwaves in the GHz range has increased because of the demand for large data transmission. However, the problem of electromagnetic interference (EMI) has become serious, and much attention has been paid to microwave absorption materials. We have investigated magnetic loss of permanent magnet materials at natural resonance frequency, and have succeeded in the development of microwave absorbers using M-type (or W-type ferrite) and RE-Fe-B (RE: rare earth) compounds. The resonance frequency can be controlled by substitution of Fe3+ ion with other metal ion in the M-type or W-type ferrite. The resin composite of M-type ferrite shows wide bandwidth, in which the reflection loss (R.L.) is less than −20 dB. In the RE-Fe-B compounds, the substitution of RE with Sm or the fabrication of nanocomposite with a soft magnetic phase is effective method for controlling their resonance phenomena and functional frequency as microwave absorbers. The powder with fine α-Fe structure, which is produced by the disproportionation reaction of RE-Fe compounds, is useful for the filler of resin composite microwave absorbers in several GHz range.