巻号一覧
38 巻, 6 号
選択された号の論文の29件中1～29を表示しています
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藤田 豊久, Balachandran Jeyadevan, 真宮 三男1991 年 38 巻 6 号 p. 695-699
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーThe α-Fe particles were prepared by reducing the ferrous ion in sodium borohydride aqueous solution in the presence of surfactant, sodium oleate. The particles prepared were dispersed stably in tetramethylammonium (TMA) hydroxide aqueous solution with sodium dodecylbenzenesulfonate (SDBS). The stability of the suspension depended on the SDBS and TMA hydroxide concentration. The effect of iron concentration on the viscosity of suspension was studied and the apparent adsorbed layer thickness was evaluated to be about 10 nm. The suspension when exposed to a magnetic field distribution was separated into two phases. The sunk black phase retained the flowability and did not coagulate under the employed magnetic field distribution, this being considered as a stable magnetic fluid. For example, a magnetic fluid with saturation magnetization of 0.036 T was prepared. Optical microscopic observation of 2 μm thin magnetic fluid film under magnetic field showed the existence of iron particle clusters. The viscosity of the magnetic fluid measured in a cylindrical viscometer showed about two fold increase in viscosity under a magnetic field of 280 kA/m.抄録全体を表示PDF形式でダウンロード (1269K) -
黒木 康徳, 川崎 亮, 渡辺 龍三1991 年 38 巻 6 号 p. 700-706
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーPulsated orifice injection apparatus was devised for the preparation of monodispersed metal particles, in which molten metal was injected from a small orifice by a clipping action of a pressure transmitting diaphragm given by a piezoelectric actuator. While the displacement of the diaphragm was varied, each pulse pressure yielded a liquid droplet having a size almost equal to the orifice diameter. The standard deviation of the mean diameter of the particles is 15%, which is about the same as that for sol-gel particles. The effect of process parameters, such as injection rate, pulse frequency, injection atmosphere and cooling rate on the particle formation, as well as the kinetics of liquid droplet injection, is discussed.抄録全体を表示PDF形式でダウンロード (2229K) -
Zrへの応用佐野 利夫, 田渕 光春, 金子 泰成1991 年 38 巻 6 号 p. 707-711
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーPowder preparation by using spark discharge between zirconium rotating disk electrode and wire electrode in liquid nitrogen and in deionized water were studied.
Zirconium and zirconium nitride (ZrN) powders containing spherical and irregular shape particles were obtained in the case of liquid nitrogen. By applying deionized water instead of liquid nitrogen, spherical particles containing zirconium and zirconium oxide (ZrO2, monoclinic) powder were formed.
Spherical particles were formed by drop splashing from melting zone on electrodes. Irregular shape particles were formed by spalling from nitrized zone on electrodes.抄録全体を表示PDF形式でダウンロード (2782K) -
鎌田 政智, 山中 雅樹, 徳永 洋一1991 年 38 巻 6 号 p. 712-717
発行日: 1991/08/25
公開日: 2009/12/04
ジャーナル フリーCrB fine powder was added to austenitic stainless steel (SUS304L) powder compacts in order to enhance the ability of sintering by liquid phase formed through a eutectic reaction. The effects of CrB addition on the mechanical properties of sintered compacts were investigated.
Tensile properties are improved by liquid phase sintering because of densification, disappearance of small pores finely dispersed in the matrix and rounding of pores. Over 0.5 wt% CrB addition, however, produces the networks of liquid solidified microstructure which affect negatively the improvement of ductility.
Impact resistance is also improved by CrB addition. The fracture occurs by the mechanism of pore enlargement and coalescence in low density specimens, while in high density specimens, that occurs along the liquid solidified microstructure. The impact value of high density specimens below room temperature decreases with falling temperature, owing to the embrittlement of liquid solidified microstructure.抄録全体を表示PDF形式でダウンロード (4213K) -
植木 光生, 鈴木 寿1991 年 38 巻 6 号 p. 718-722
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーCutting performance for S48C of nitrogen-free TiC-10 vol%Mo2C-10 vol%Ni cermet (A-cermet) was mainly studied comparing with nitrogen contained TiC-20 vol%TiN-10 vol%Mo2C-10 vol%Ni cermet (B-cermet), in relation to their mechanical properties such as transverse-rupture strength, hardness from room temperature to 1000°C, creep resistance at 1050°C. Specimens having grain sizes of 2.5, 1.5 and 1.0 /μm were used in both cermets. It was found that, at low cutting speed (130 m/min), a coarse grained A-cermet was the most excellent in flank wear (VB) among both cermets with different grain size, and the VB value of A-cermet was always lower than B-cermet with the same grain size. On the other hand, at high cutting speed (250 m/min), VB of a fine grained A-cermet was excellent and nearly the same that of coarse grained B-cermet. As for the resistance to fracture, B-cermet seemed to be superior to A-cermet. A further study is needed to test whether the nitrogen contained cermet was really useful for cutting tool materials or not.抄録全体を表示PDF形式でダウンロード (1541K) -
鳥塚 史郎, 西尾 浩明1991 年 38 巻 6 号 p. 723-728
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーFull dense TiB2 sintered bodies containing 2 mol%Y2O3-ZrO2 up to 40 wt% were fabricated by glass encapsulation HIP method. Mechanical properties of these TiB2-(2 mol%Y2O3-ZrO2) sintered bodies were evaluated and compared to those of TiB2-ZrO2 sintered bodies, which were fabricated and evaluated in our previous work. Three-point-bending-strength of TiB2-10-20 wt%(2 mol%Y2O3-ZrO2) was 1160-1200 MPa, which is almost the same strength as that of TiB2-10 wt%ZrO2. Our previous work showed that the addition of 10 wt%ZrO2 was effective in improving the bending strength of sintered TiB2. In this work, it was found that the addition of 2 mol%Y2O3-ZrO2 was more effective in improving the bending strength of sintered TiB2 than the addition of plain ZrO2, by the comparison of TiB2-(2 mol%Y2O3-ZrO2) and TiB2-ZrO2 strength. Vickers hardness of TiB2-(2 mol%Y2O3-ZrO2) was also higher than that of TiB2-ZrO2. On the other hand, higher fracture toughness was obtained in TiB2-ZrO2. These differences of mechanical properties between TiB2-(2 mol%Y2O3-ZrO2) and TiB2-ZrO2 were caused by the differences of monoclinic ZrO2 content in the sintered bodies.抄録全体を表示PDF形式でダウンロード (3185K) -
植木 光生, 木下 聡, 鈴木 寿1991 年 38 巻 6 号 p. 729-732
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーThe nitrogen (N) contained TiC based cermets have usually been made by using Ti(C, N) or TiN. However, the difference in properties of cermets affected by N adding method seemed not to be clarified until now. Then, the difference in mechanical properties between Ti(C, N) and (TiC+TiN) based cermets was mainly studied. It was found that the hardness at room temperature and high temperature (1100°C) was superior in (TiC+TiN) based cermet to the other owing to the finer carbo-nitride structure. The wear resistance at high speed cutting of S48C was also superior in (TiC+TiN) based cermet. It was also concluded that such properties as transverse-rupture strength, creep strength, composition of binder and hard phases, etc. were nearly the same in two sorts of cermets.抄録全体を表示PDF形式でダウンロード (1416K) -
沖中 秀行1991 年 38 巻 6 号 p. 734
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (50K) -
真島 一彦, 篠原 雅志, 勝山 茂, 景山 景介, 永井 宏1991 年 38 巻 6 号 p. 735-739
発行日: 1991/08/25
公開日: 2009/12/04
ジャーナル フリーAs a microwave dielectric. BaTi4O9 is profitable for its high Q value, however, it is disadvantageous for its high temperature coefficient.
In our investigation reported here, we used ZnO-Ta2O5 system compounds said to own negative temperature coefficient, added them to BaTi4O9 and studied the effects.
Results obtained are summarized as follows:
(1) The addition of ZnO and Ta2O5 to BaTi4O9 improved both the Q value and temperature coefficient, and the best composition obtained were regarded thus; BaO:17.50mol%, TiO2:70.00mol%. Ta2O5:0.75mo1% and ZnO:11.75mol%.
(2) We observed black part with poor Zn and white part with rich Zn in the structure both in the center and on the surface of sintered specimen above mentioned, and it was confirmed that the structure in the center was more coarsened than that on the surface, comparatively.
(3) Adding Mn2O3 to BaTi4O9. we obtained identical structure in the center and on the surface, with the Q value and temperature coefficient both improved. It is confirmed that the most suitable amount of Mn2O3 to add is 0.18mol%, in this occasion.抄録全体を表示PDF形式でダウンロード (3178K) -
真島 一彦, 山下 敬士, 勝山 茂, 三島 信, 永井 宏1991 年 38 巻 6 号 p. 740-744
発行日: 1991/08/25
公開日: 2010/07/12
ジャーナル フリーThe stability of Ba2Ti9O20 phase was investigated by sintering of BaO⋅4.5TiO2 binary specimen and BaO⋅4.29TiO2⋅0.21SnO2 ternary specimen. When BaO⋅4.5TiO2 specimen was sintered at 1250°C, 1300°C and 1350°C, BaTi4O9+TiO2. BaTi4O9+Ba2Ti9O20+TiO2 and BaTi4O9+TiO2 phases were detected. respectively. On the other hand, the BaO⋅4.29TiO2⋅0.21SnO2 specimen formed BaTi4O9+Ba2Ti9 O20+TiO2, irrespective of sintering temperature between 1250°C and 1375°C. Corresponding to the above mentioned result, the Q values of BaO⋅4. 5TiO2 specimen sintered at 1250°C-1275°C, 1300°C-1325°C and 1350°C-1375°C are confirmed to be about 6000, about 4500 and about 6000. respectively. and BaO⋅4.29TiO2⋅0.21SnO2 specimen showed nearly constant Q value of about 4000. irrespective of sintering temperature between 1250°C and 1375°C.抄録全体を表示PDF形式でダウンロード (4140K) -
景山 恵介, 高橋 順一1991 年 38 巻 6 号 p. 745-748
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーThe effects of the replacement of Sr by Ba for Sr(Ga1/2Ta1/2)O2 ceramics (SGT) on microwave dielectric properties and microstructures were investigated. With the increase of the replacement of Sr to Ba, a single perovskite phase changed to mixed crystalline phases, which were composed of (Ba, Sr)5Ta4O15 or unknown phases in addition to a perovskite phase. Microwave Q and temperature coefficients of resonant frequencies (τf) were improved with the replacement of Sr by Ba. (Ba0.6, Sr0.4)(Ga1/2Ta1/2)O3 ceramics showed a dielectric constant of 27.7, Q value of 10000 at 9GHz and τf=-4ppm/°C. The relationship between microwave Q and microstructures is discussed.抄録全体を表示PDF形式でダウンロード (3446K) -
杉原 淳, 寺島 良充, 木佐森 克彦, 岡崎 清1991 年 38 巻 6 号 p. 749-752
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーWetting properties of silver on Barium titanates (hereinafter, BT), on reduced BT (BaTi03-δ) and on reoxidized BT (BaTiO3-δ+x) of reduced BT were studied using furnace with a telescope to measure contact angle in vacuum with elevating temperatures.
The effects of surface roughness, sintered density, and the surface-oxidized conditions of the ceramics were examined and discussed. In addition, Ag containing borosilicate glass was also investigated to discuss the effects of the glass on the wetting properties on BT.
As a result, the followings were clarified: The contact angles were reduced depending upon the sintered densities and surface roughness of ceramics, and oxidized layers on the ceramics affected to reduce the contact angles as well. The mechanism of adhesion of Ag on the ceramics was also discussed. The glass frits were thought to wet the ceramics regardless of sintered density and surface roughness.抄録全体を表示PDF形式でダウンロード (2409K) -
伊賀 篤志, 伊藤 昌宏1991 年 38 巻 6 号 p. 753-755
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーTemperature dependence of I-V characterisics was investigated in semiconducting ceramics with the compositions of SrTiO3 with three additives (MgO-TiO2-SiO2-system, Nb2O5 and ZrO2) and four additives (MgO-TiO2-SiO2-system, Nb2O5, ZrO2 and perovskite-type compound). I-V curves of some SrTiO3 ceramics with four additives did not shifted toward higher current regions in spite of increased temperature. This is possibly explained in terms of the temperature dependence of the permitivity e of SrTiO3 ceramics.抄録全体を表示PDF形式でダウンロード (175K) -
豊田 幸夫, 大西 康司, 高田 光裕1991 年 38 巻 6 号 p. 756-759
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーOptical shutter array of an electrophotographic page printer was made from HIP'ed PLZT ceramics. There was a marked variation of the light intensity among individual apertures of the shutter array when the ceramic having coarse grains was used. This is caused by the inhomogeneous distribution of the portion having different birefringence at a given electric field direction. The portion has an approximate diameter of a grain. So the optical shutter array should be made of PLZT ceramics with fine grain size and high optical transmittance.抄録全体を表示PDF形式でダウンロード (1908K) -
大内 宏, 西田 正光1991 年 38 巻 6 号 p. 760-763
発行日: 1991/08/25
公開日: 2009/12/04
ジャーナル フリーCeramics plastic composite materials consisting of piezoelectric hard materials with a high QM, a high k33 and a low s33 properties for the ceramics and epoxy resin for the plastic were fabricated. Dielectric, piezoelectric and elastic properties were studied for the thickness ex-pansion of composite materials. Piezoelectric composite materials with the properties of about 1/3 times lower densities (2.61 g/cm3), about 1/10 times lower relative dielectric constant(130), about 10 times higher elastic compliance constant (138.6×10-12m2/N) and 4.4 times higher piezoelectric voltage constant (101×10-3V⋅m/N) than the usual ceramics were obtained.抄録全体を表示PDF形式でダウンロード (196K) -
西川 友三1991 年 38 巻 6 号 p. 766
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (61K) -
三浦 秀士, 本田 忠敏, Randall M. German1991 年 38 巻 6 号 p. 767-773
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーMetal injection molding(MIM) has been expected to have significant utility in manufacturing of relatively small and complex shaped parts, and also MIM has enormous potential even in the ferrous market. The aim of this study is to attain high performance ferrous materials by using 4600 steel component powders. However, the mechanical properties of powders shaped by MIM techniques are affected by the grain size, sintered density, and carbon content. Especially, it is very important to control the carbon level which depends on several factors such as debinding approach and sintering conditions (atmosphere, temperature, and time). In this paper, effects of the above factors on the carbon retention and structure have been investigated by means of carbon analysis, optical microscopy, and density and hardness measurements.
Solvent debinding followed by final thermal debinding produced the fine and homogeneous sintered structures which suggest excellent properties. Although the carbon content was very sensitive to the debinding and sintering conditions, it was found that the residual carbon content was mainly controlled by adjusting the weight loss after debinding.抄録全体を表示PDF形式でダウンロード (4964K) -
笠原 範雄, 斎藤 勝義, 寒川 喜光, 金子 泰成1991 年 38 巻 6 号 p. 774-776
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーWhen Producing P/M parts by the MIM, the debinding step takes the longest time of its process. How to reduce the binder removal time is the key to the MIM, though the injection machine forming is highly productive. The rapid binder removal could be achived by the solvent extraction. When using copper powder, the solvent extraction needed 8 houus, though the thermal debinding needed more than 40 hours. The sintered pert at 1020°C had a relative density of 95%. The pore was all closed, which was remarkable of the MIM sintered part. Two types of the binder were discussed here. One consisted of polyolefin and oil, another consisted of polyethylene glycol. Using the polyethylene glycol, the miscibility of the binder had been much improved.抄録全体を表示PDF形式でダウンロード (130K) -
寒川 喜光, 斎藤 勝義, 金子 泰成, 笠原 範雄1991 年 38 巻 6 号 p. 777-781
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーRod like test piece and bobbin type test piece were produced by the injection molding of alumina or zirconia powder with several organic binders including polyethylene glycol(PEG). Following injection molding, these test pieces were submerged in a alcohol to extract PEG in the organic binders for 1-12 hour at room temperature. After the solvent debinding process of PEG by alcohol, the test pieces containg the residual binders were heated up to 400°C at a rate of 20-200°C/hr, and then sintered at 1300-1620°C. The main results are summarized as follows: 1)This solvent debinding process(SDP)of PEG by alcohol is nearly 5-10 times faster than conventional thermal debinding process. 2)The density of the sintered test pieces go up to over 99% of theoretical values by means of SDP. 3)It makes possible to produce the CIM parts with ultra fine zilconium powder(>15m2/g) by means of SDP.抄録全体を表示PDF形式でダウンロード (1378K) -
宮本 敬, 稲村 偉, 高橋 弓弦, 宮本 大樹1991 年 38 巻 6 号 p. 782-786
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーAl2O3 ceramics was fabricated by low pressure injection molding and successive normal sintering and HIP sintering. Fine particles of Al2O3 with mean particle size of 0.23μm were used as starting
matereal. By adding 17-18 wt% of wax binder Selna E-146 to the powder, ceramic slurry was successfully injected to form an uniform compact.
In normal sintering at 1275°C, sintered specimen showed 99% bulk density. The mean bending strength 71.6kgf/mm2 was obtained in the specimen normally sintered at 1300°C for 3 h.
On the other hand, the specimen HIP sintered at 1300°C for 3 h showed bulk density of 99.7% and the maximum mean bending strength of 81.0kgf/mm2. According to SEX observation of fractured surface, grain size of HIP sintered body at 1300°C was 0.5-2.0μm in size and fracture within grain was frequently observed. Bending strength decreases as sintering temperture raises above 1500°C, because of remarked grain growth.抄録全体を表示PDF形式でダウンロード (1086K) -
黒田 義和, 深浦 健三, 砂田 久吉, 泉 久司1991 年 38 巻 6 号 p. 787-790
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーY-PSZ ceramics containing various amount of Al2O3 were fabricated by injection molding method. The green compacts were debound in heating rate of 1.1×10-3K/s up to 723K for controlled burnout of the organic binder, and were sintered at 1823K for 10.8ks.
Vickers hardness, fracture toughness test and bending test were performed to investigate mechanical properties of ceramic composites at the room-temperature.
Because the mechanical properties of ceramic composites depend severely on their microstructures, we discussed the relationship between mechanical properties, microstructures and residual stresses of ZrO2 phases.抄録全体を表示PDF形式でダウンロード (4058K) -
河野 隆年, 佐々木 英幸, 鎌田 公一, 小原 康司, 川原 業三1991 年 38 巻 6 号 p. 791-795
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーFor shortening debinding times on the metal injection molding, the thermal debinding method with burying process was investigated. The powders made up by the mixture of reduced iron powder (d:70μm), carbonyl iron powder (d:6.4μm) and carbonyl nickel powder (d:9.3μm) were used. The carbon powders(0.2wt%) were used as the luburicant for the powders. And the montan wax and the polyethylene wax were used as binder. The green bodies buried in the zirconsand were debinded under heating from room tenperature to 450°C in N2 flow(0.5 ?? /min). The debinding times were from 9 hour to 22 hour. Then the debound bodies were sintered at 1100, 1180 and 1250°C in H2 atomosphere with heating rate of 1000°C/h.
As the results, about 90 wt% binders were dibined and then the sintered parts at 1250°C showed the relative density of 80-87%, the elongatione of 2-7%. the tensil strength of 19-27Kgf/mm2 and the hardness of 71-94(HRF).抄録全体を表示PDF形式でダウンロード (2936K) -
武田 徹, 皆川 和己1991 年 38 巻 6 号 p. 796-799
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーIn order to obtain spherical iron fines for the raw materials of the injection molding, atomizing conditions of molten iron were investigated by using the high pressre water atomizer developed at NRIM. The melt was atomized by the water jet with the velocity of 200m/s. The mean particle size measured with Coulter Counter was of 8μm. Carbon addition of 0.5% to the melt made the shape of powders spherical and increased the tap density ratio from 54% to 60%. Carbon in fine particles was easily removed by heating at 820K, 7.2ks in H2. Atomized powders of -20μm showed good sintering properties comparable to carbonyl powders having the same particle size at the temperature of 1520K. The mixture of iron powders and polyethylene wax of 6-7mass% had a suitable flow properties for the use of the metal injection molding. The shrinkage during sintering of dewaxed compacts was higher than that of compressed compacts.抄録全体を表示PDF形式でダウンロード (2888K) -
武川 淳二郎1991 年 38 巻 6 号 p. 800-803
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーThe debinding process of injection molded Fe-8%Ni mixed powder compacts containing binder of different compositions of polymers to waxes was investigated, and the effect of the binder compositions and debinding conditions on the sinterability of the compacts were developed.
It was shown that the distortion in debinding was minimum when the ratio of polymer to the total binder contents was 0.35. When debinding in air above 280°C, the binder removal(%) of compacts began to decrease with increasing temperature, and the compacts exhibited considerable shrinkages, while in N2 atmosphere, the binder removal(%) increased with temperature and the compacts exhibited some swelling. In the case of compacts debound in air, the sintered densities increased with increasing the debinding temperature up to 350°C then decreased rapidly at the higher temperature. On the other hand, debound in N2, the sintered densities were not so changed by the debinding temperature and showed remarkably lower values compared with the compacts debounnd in air, below the debinding temperature of 350°C.抄録全体を表示PDF形式でダウンロード (297K) -
高橋 清造, 中川 威雄1991 年 38 巻 6 号 p. 804-809
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーCompaction was carried out by PPFM(Press Powder Flow Molding) from carbonyl iron powder granulated with a little resin binder(PVA), including lubricant(ZnSt) and some amount of liquid binder (Liquid Paraffin). The density of green compact increases according to the addition of ZnSt and Liquid Paraffin due to the increase of cup wall density, and it can be concluded that the powder flows out from cup bottom to wall due to the lubricating effect by ZnSt and Liquid Paraffin.
The Liquid Paraffin volume in green compact by PPFM is about half of total binder volume, and so the debinding of green compact by PPFM is more easy by PIM(Powder Injection Molding). The difference in diameter at position of sintered compact performed under 294MPa from powder of the addition of 1wt% ZnSt and 4wt% Liquid Paraffin was a little enough and sintered compact was nearly uniform in density distribution.抄録全体を表示PDF形式でダウンロード (1481K) -
三浦 立, 関口 順一, 内田 雅浩, 大脇 康志, 斑目 広和1991 年 38 巻 6 号 p. 810-813
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーSintering behavior and mechanical properties of the injection molded SKH53 high speed steel were investigated. Water atomized fine powder mixed with organic binder was molded by injection into transverse rupture specimen. After thermal debinding, specimens were sintered in vacuum at the temperatures between 1215 and 1246°C for 1 hour. On the sintered specimens, transverse rupture strength was estimated and microstructures were examined in detail.
The debound specimen exhibited very rapid densification at the tempreature between 1220 and 1225°C, which is characteristic to liquid phase sintering. Above 1225°C, nearly full density was attained and the specimens showed high transverse rupture strength more than 200kg/mm2. When the sintering temperature of 1240°C was exceeded, however, transverse rupture strength sharply decreased with the formation of continuous grain boundary carbides.
For the binder and the debirding method used in this study, the amount of carbon picked up from binder was inferred about 0.17wt% from the chemical analyses of the powder and the sintered specimen.
In conclusion, excellent mechanical properties can be obtained by applying powder injection molding to SKH53 high speed steel if sintering temperature is strictly controlled. But pick-up of carbon from binder should be taken into consideration to control carbon content of sintered parts.抄録全体を表示PDF形式でダウンロード (2785K) -
Kenzo Fukaura, Yoshikazu Kuroda, Hisakichi Sunada, Hisashi Izumi1991 年 38 巻 6 号 p. 814-819
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーMechanical properties of the electron-beam welded joints of the sintered SUS304L which are produced by the injection moulding method are investigated to clear the influence of welding on the tensile and the fatigue strength.
The results obtained are summarized as follows;
(1)Formation of welding defects is strongly affected by beam active parameter and welding speed.When they have appropriate values, welding defects aren't created, except that large voids are formed at or near the bond.
(2)When the sintered stainless steel is welded under the optimum welding condition, the tensile strength of the as-welded joint decreases about 10% and the fatigue limits of the as-welded joint and the joint whose undercut is removed decrease about 20% and 5% respectively as compared with that of the un-welded one.
(3)In as-welded specimen, the fatigue crack of the electron-beam welded joint initiates at the root of the undercut in welds, on the other hand, in the specimen whose surface irregularity is removed, it initiates at the intereface of delta phase and austenite phase near the bond.
(4)The fatigue crack of the electron-beam welded joint of the sintered stainless steel propagates along the bond because large voids exist there.
(5)It is confirmed that the electron-beam welded joints of the sintered stainless steels under the optimum welding condition can be put into practical use.抄録全体を表示PDF形式でダウンロード (4125K) -
村上 雅英, 金澤 良道, 柳谷 彰彦, 田中 義和1991 年 38 巻 6 号 p. 820-823
発行日: 1991/08/25
公開日: 2010/07/12
ジャーナル フリーIt is known that Fe-9.6%Si-5.4%Al alloy called “Sendust” is soft magentic material well suited for a magetic head becuase of high permeability and high magnetic flux density and high resistance to wear as well.
A series of investigations have been made by the authors to improve mechanical properties of this alloy, for instance, by extrusion of powder for higher density and finer grains. The metal injection molding process widely adopted in recent years was tried in this work first to manufacture near-net shape products of such very brittle material as this composition from gas-atomized powder and then to improve density and grain size.A comparison was also made between the injection molded and the cast material of the same composition.
We have found some characteristics mentioned below of the Sendust alloy injection molded from gas-atomized powder.1) -38μm powder, coarser than -20μm regularly used for metal injection process, was molded successfully from compound of 69vol.% powder which was higher than a usual ratio.2) Such coarse powder as -38μm was processed to satisfactorily dense, evenly fine grained and segregation-free material of good magnetic properties with stability in shape.抄録全体を表示PDF形式でダウンロード (3548K) -
古川 満彦1991 年 38 巻 6 号 p. 824-830
発行日: 1991/08/25
公開日: 2009/05/22
ジャーナル フリーCeramic Cutting tool materials are required high fracture toughness, and tool materials such as Si3N4, and Al2O3 with TiC and SiC whiskers added, have been developed to satisfy this need. In manufacturing technology the introduction of hot pressing and hot isostatic pressing techniques have enhanced material strength and fracture toughness by enabling ceramic materials to be made with finer and more uniform grains.
This paper discusses the current state of ceramic tool materials and their manufacturing techniques.抄録全体を表示PDF形式でダウンロード (1430K)
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