巻号一覧
50 巻, 7 号
選択された号の論文の12件中1～12を表示しています
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上ノ薗 聡, 尾崎 由紀子2003 年 50 巻 7 号 p. 515-521
発行日: 2003/07/15
公開日: 2009/05/22
ジャーナル フリーThe factor that determines the flow characteristics of the segregation-free iron mixed powder which contains ethylene-bis-stearamide as a lubricant powder was investigated. Sample powders used were as follows; (A) iron powder (B) iron powder mixed with ethylene-bis-stearamide powder (C) iron powder mixed with graphite powder (D) iron powder bonded with graphite powder by the organic binder(binder treated iron powder) and (E) binder treated iron powder mixed with ethylene-bis-stearamide powder.
Iron powder gave the best flow character and the binder treated powder with the free lubricant powder gave the worst flow character.
The data above mentioned and the data related to the frictional properties of the sample powders indicated that the interaction between the binder on the iron powder and the lubricant powder or the interaction between the lubricant powders affected strongly on the flow characteristics of the segregation-free iron mixed powder containing ethylene-bis-stearamide as a lubricant.抄録全体を表示PDF形式でダウンロード (1898K) -
堀内 健史, 那須 昭一, 大橋 憲太郎, 杉俣 悦郎2003 年 50 巻 7 号 p. 522-526
発行日: 2003/07/15
公開日: 2009/05/22
ジャーナル フリーPolycrystalline or single crystal HgI2 intercalated Bi2Sr2CaCu2Oy, (Bi2212) superconductors have been synthesized and their structure and superconductivity have been studied. According to X-ray diffraction, the a and c axis-lengths were estimated to be 0.54 nm and 2.26 um, respectively. The expansion of c axis length was 0.72 nm, compared to that of host Bi2212 (3.09nm/2=1.54nm), while a axis length did not changed. From ac susceptibility and resistivity measurements, superconducting transition onset temperature (Tc) for polycrystalline HgI2 intercalate was found to be 82K, which is higher than that of host 75K. On the other hand, resistivity measurements for single crystal HgI2 intercalate was showed to be 75K, which is lower than that of host 95K. The effect of HgI2 intercalation on the superconductivity is discussed from the viewpoint of hole concentration change.抄録全体を表示PDF形式でダウンロード (327K) -
和田 任弘2003 年 50 巻 7 号 p. 527-533
発行日: 2003/07/15
公開日: 2009/12/04
ジャーナル フリーThe tool life in turning of sintered steels becomes shorter than that in turning of melted steels such as carbon steels. In order to clarify an effective tool material for the cutting of hardened sintered steel, the tool wear, the surface roughness and the cutting forces were experimentally investigated. The hardened sintered steel was turned with three kinds of PVD coated cemented carbide tools and four kinds of CBN tools. The main results obtained are as follows: (1) In the PVD coated cemented carbide tools, the wear progress of Ti(C, N) coated cemented carbide tool was slowest. (2) In the cutting of hardened sintered steel with the Ti(C, N) coated cemented carbide tool, both the surface roughness and the cutting forces were almost constant under the cutting speed 0.14m/s to 1.67m/s. (3) In the CBN tools, the wear progress of CBN tool which has Co based binder was slowest. (4) The mirror finish was clarified to be possible in the low speed cutting of hardened sintered steel with the CBN tool which has Co based binder.抄録全体を表示PDF形式でダウンロード (7657K) -
Kazuhiko Tanaka, Nobuaki Asada, Koji Hayashi2003 年 50 巻 7 号 p. 534-544
発行日: 2003/07/15
公開日: 2009/05/22
ジャーナル フリーThe syntheses of new mono-carbonitrides of W and/or Mo, i.e., W(C, N), Mo(C, N) and (W, Mo)(C, N), which are thermodynamically unable to be generated by using nitrogen gas of normal pressure, have been succeeded by the authors by using CH4+NH3 mixed gas of normal pressure (normal-pressure method) and C powder+nitrogen gas of high pressure (high-pressure method). The formations of these mono-carbonitrides as well as of general compounds by those methods have been explained by applying traditional Ostwald's step rule and virtual-pressure concept for normal-pressure method, and Le Chatelier's principle for high-pressure method, respectively. These explanations, however, are based only on the macroscopic level, but not on the atomic level.
In this paper, we newly proposed atomic models for the formation process of W(C, N) in both normal- and high-pressure methods, mainly based on the previous experimental results. The models include the concepts of "nascent atoms" and "nitrogen molecular cluster in supercritical fluid", etc., respectively.抄録全体を表示PDF形式でダウンロード (3027K) -
川村 悟史, 桑野 壽2003 年 50 巻 7 号 p. 545-550
発行日: 2003/07/15
公開日: 2009/12/04
ジャーナル フリーPure iron powders were mechanically milled to produce nano crystallite with the grain size of 13nm which was measured by transmission electron microscope. The nano crystalline iron powders were consolidated by Spark Plasma Sintering (SPS) in a temperature range from 300 to 900°C at 71 or 141MPa. Optical (OM) and transmission electron microscope (TEM) observations were performed to measure the grain size. X-ray diffraction (XRD) was also done to measure the grain size by both the Scherrer method and the Wilson method. The grain size measured by XRD on the sintered specimen is smaller than that measured by TEM and OM by a factor about 1/3 and 1/100, respectively. The grain size of the as-milled powders increases to 33-50nm and to 2-5μm after the sintering at temperatures of 300-500°C and 600-900°C, respectively. The 600°C sintering produces a patchwork structure which is composed of the grains in 64nm diameter and those in 2μm. The characteristic structure seems to be a result of the abnormal grain growth. In order to make a dense compact with grain sizes less than 50nm, sintering should be done at temperatures lower than 600°C with higher pressures.抄録全体を表示PDF形式でダウンロード (4126K) -
梶川 義明2003 年 50 巻 7 号 p. 552
発行日: 2003/07/15
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (84K) -
金型フリーによる複雑3次元部品の製造に向けて前川 克廣2003 年 50 巻 7 号 p. 553-560
発行日: 2003/07/15
公開日: 2009/05/22
ジャーナル フリーRapid prototyping (RP) technology has given the product designer access to a vast arsenal of tools and technologies unprecedented in the history of manufacturing. The incredible pace of desktop computing with the market availability of 3D software and the development of rapid prototyping technology allows product design to engage more freely with new ideas, to produce prototypes and to carry out thorough testing in a shorter time. The present review first describes significant roles of RP from the viewpoint of value engineering. Next, the fundamentals of information-driven RP technology are outlined, together with its typical applications. Then, the state-of-the-art technology of RP-based metal fabrication including Selective Laser Sintering (SLS) and GreenTape Laser Sintering (GTLS) is extensively surveyed: the principle, the machine architecture and various product applications such as stainless-steel rotors, stainless-steel heat exchangers, copper-bonded cBN tools and titanium artificial bones. Finally, the future of powder-based RP technology is envisaged.抄録全体を表示PDF形式でダウンロード (7119K) -
大塚 淳, 武川 淳二郎2003 年 50 巻 7 号 p. 561-565
発行日: 2003/07/15
公開日: 2009/05/22
ジャーナル フリーIt has been known B is the most effective sintering enhancer for ferrous powders. Therefore, it also seemed to be effective as the sintering enhancer of high speed steel powders. This study was done to make certain the effectiveness of B addition on the sinterablity of the injection molded SKH51 steel powder compacts. We used the gas-atomized SKH51 steel powder with 0.4 mass% B, as a feed stock. It was shown that the SKH51 steel powder compacts with B were sintered to near the theoretical density at a relatively low temperature at 1463 K, whereas the density of compacts without B was much lower at that temperature. The tensile strength of the MIMed compacts with B was about three times higher than that of the compacts without B. The hardness of MIMed and heat treated compacts was increased with increasing the sintering temperature.抄録全体を表示PDF形式でダウンロード (3695K) -
佐藤 憲研, 伊藤 芳典, 針幸 達也, 三浦 秀士2003 年 50 巻 7 号 p. 566-570
発行日: 2003/07/15
公開日: 2009/12/04
ジャーナル フリーThe combinations of the same stainless steels (SUS316L/SUS316L, SUS430U/SUS430L) and the different stainless steels (SUS316L/SUS430L) were joined with the pastes containing the stainless steel powder in MIM process. For joining the same stainless steels, the values of joined strength were 400MPa for SUS316U/SUS316L compact sintered at 1623 K, and 320 MPa for SUS430L/USUS430L compact sintered at 1373 K respectively.
For joining the different stainless steels, the values of joined strength for SUS316L/SUS430L compacts sintered at 1623 K were 330 MPa by using the paste with SUS316L, and 370 MPa by using the paste with SUS430L.
At the joined area of SUS316L/SUS430L sintered compacts, the mixed layer (over 100μm thickness) of ferrite and martensite phases was observed.抄録全体を表示PDF形式でダウンロード (2648K) -
河合 伸泰, 脇浜 智2003 年 50 巻 7 号 p. 571-576
発行日: 2003/07/15
公開日: 2009/05/22
ジャーナル フリーThe plastically deformed layer induced by drill cutting of 4650 sintered steels using prealloyed and elemental powders were investigated in this study. The microstructures, pore elimination and microhardness on the surface of cut holes were determined to evaluate the surface deformed layer thickness. The results obtained are summarized as follows;
1. The internal pore area tends to increase from the drill hole surface toward inside.
2. The metal flow is observed at the drill hole surface, but the boundary is not so clear that the thickness of plastically deformed layer cannot be measured.
3. Microhardness is comparatively easy to estimate the thickness of plastically deformed layer.
4. The rate of pore area becomes smaller with the progress of cutting.
5. It is easy to measure the plastically deformed layer thickness of ferrous sintered steels in order of microhardness, internal pores area and microstructures.抄録全体を表示PDF形式でダウンロード (3100K) -
田島 伸, 服部 毅, 堀田 昇次, 近藤 幹夫, 岡島 博司, 東山 潔, 岸本 秀史2003 年 50 巻 7 号 p. 577-583
発行日: 2003/07/15
公開日: 2009/12/04
ジャーナル フリーPowder magnetic cores (or dust cores and soft magnetic composites (SMC)) are candidate materials for new type motor cores, because they have good points as follows; isotropic magnetic properties, high electric resistivity and easy recycling. However, the materials are hardly used for motors, because both their magnetic flux density and their strength are smaller than those of laminated steel. The small magnetic flux density and strength were caused by small green density. In order to increase the green density, it needs reduction the admixed lubricant and high-pressure compaction. We developed a new warm compaction using die wall lubrication with lithium stearate. According to the method, very high-density compact could be fabricated without scoring. In this instance a raw material was Somaloy500 without resin, the powder magnetic core compacted at 1176 MPa with heat treatment at 673 K had properties as follows; d=7.77Mg/m3, μm=1000, B2k=1.41T, B5k=1.61 T, B10k=1.80T, bHc=300A/m, p=4μΩm, TRS=210MPa, δmax=150MPa, andincase of Bm=1T and f=400Hz, Pc=900kW/m3, Ph=350kW/m3, Pe=550kW/m3.抄録全体を表示PDF形式でダウンロード (3706K) -
小松 敏泰, 浅香 一夫2003 年 50 巻 7 号 p. 584-589
発行日: 2003/07/15
公開日: 2009/05/22
ジャーナル フリーThis paper focused on sinter diffusion bonding technology applied to rotor core in hybrid car, which requires both magnetic properties and mechanical properties at a time, and analyzed diffusion bonding of sintered materials and the bonding area as a factor affecting it. It was obtained that the strength of the bonding zone depended on the bonding area. The satisfactory bonding strength was accomplished by increasing the bonding area through the pressure by press fitting of the inner and outer components in addition to the difference in thermal expansion of the sintered material. The obtained results showed that the density of the outer part should be close to 7.0±0.05 g/cm3 and the press fitting clearance should be in 0.275-0.335 mm, considering the soft magnetic properties and diffusion bonding strength. The rotor which bonding area ratio was more than 50% made it possible to achieve both sufficient durability and functionality.抄録全体を表示PDF形式でダウンロード (3465K)
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