巻号一覧
38 巻, 5 号
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黒木 英憲, 藤沢 伸也1991 年 38 巻 5 号 p. 571-576
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーAnisotropy of the copper-growth was investigated by a dilatometer. Hoeganaes NC 100.24 iron powder with 5 mass% copper which was precipitated by the substitution process, or admixed as an electrolytic powder, was pressed under 490MPa to form 5mm cubes. The compacts were dewaxed in dissociated ammonia, set in a dilatometer with a support and a detecting rod made of alumina, and heated at the rate of 10K/min up to 1398K and held for 30min in vacuum. The density of the boundaries penetrated by the copper, or the boundary number/length, was measured in a mixed powder compact.
Below the Ac3 transformation point of iron, both powder compacts showed shrinking tendencies in the compacting direction. The powders did not differ much from each other in dimensional changes during the Ac3 and the Ar3 transformations and the isothermal holding. The coated powder expanded in the range from the Ac3 point to the melting point of the copper. The expansion by the melting was larger for the mixed powder in both compacting and lateral directions. By adding the presintering process, the copper-growth of the mixed powder compacts was controlled to some extent.抄録全体を表示PDF形式でダウンロード (3011K) -
釘宮 公一1991 年 38 巻 5 号 p. 577-580
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーMetal powder deformation and reformation mechanisms are studied for the better understanding of the mechanical milling. Thinning of metal powders has been characterized in detail, using single component and spherical powder of N2 atomized FeAlSi alloy, to simplify the analyses. Microstructure analyses by TEM and ED show that platelets after milling are very thin and consisted of fine microcrystals with preferred orientation. The observation of the morphology of the platelets suggests that the appearance of the malleability of powders due to conforming foreign particles into matrix powders results in a formation of the lamellar structure.抄録全体を表示PDF形式でダウンロード (2760K) -
金子 武1991 年 38 巻 5 号 p. 581-585
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーIn order to improve the mechanical properties of W-Ni-Fe heavy alloys, the mechanical properties of this alloy containing Re were studied.
The Re modified alloys exhibited a smaller grain size than unalloyed system. The addition of Re to classic W-Ni-Fe heavy alloy results in an increase in strength and hardness and decrease in elongation.
This property combination results from the aggregate effects of grain size reduction due to the addition of Re.
These results were discussed in terms of microstructures, size of fracture source, toughness of matrix, etc...抄録全体を表示PDF形式でダウンロード (2867K) -
藤森 哲雄, 瀧 英剛, 山本 恭永, 岡田 厚正1991 年 38 巻 5 号 p. 586-590
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーSynthetic diamond grits in a metal bonded sintering tool are known to reduce the strength after heating at sintering process. In this study, a strength testing method with a single particle was applied to examine the strength of diamond before and after heating at an actual sintering temperature, and the thermal behaviour of diamond was investigated by the scanning electron microscope and the electron probe micro analyzer.
As the result, it was clarified that the deterioration of diamond is originated in rough surfaces caused by the chemical reaction of diamond with bonding metal, and a precoating method of diamond is found to prevent the deterioration.抄録全体を表示PDF形式でダウンロード (2292K) -
勝村 祐次, 高橋 俊行, 鈴木 寿1991 年 38 巻 5 号 p. 591-596
発行日: 1991/07/25
公開日: 2009/12/04
ジャーナル フリーThe flaking phenomenon often appearing in Al2O3-TiC ceramics tools in turning of alloyed tool steels was studied, as a continuation of the previous reports. The Al2O3-TiC ceramics having 10-50 mass%TiC and different grain size of TiC were prepared by hot-pressing, and the ceramics tools were subjected to turning tests of SKD11 (ASTM, HB).
It was confirmed that the tools with lower or higher TiC content and with coarser TiC grains showed generally low resistance to flaking. It was found that the flaking originated from a micro-crack formed on the pre-honing surface. The formation of the micro-crack was considered as follows. In the case of the tools with lower TiC content, the amount of flank wear was apt to increase, leading to the increase in the resultant cutting force which sheared the crater surface. On the other hand, in the case of tools with higher TiC content, the amount of adhesion on the pre-honing surface, that is, the amount of the surface wear (crater wear) became larger since the reaction between work and tools during tests was enhanced, resulting in the generation of tensile stress on the pre-honing surface in the course of removing off of adhesion.抄録全体を表示PDF形式でダウンロード (6613K) -
上山 守1991 年 38 巻 5 号 p. 597-604
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーThe causes of the surface cracks of the multilayer ceramic substrates has been investigated. As the result, it was confirmed that the surface cracks on the multilayer ceramic substrates have been caused by various stresses generated between the alumina layer and W metallized conductor while they were cofired.
These cracks can be controlled by addition of the flux to the W paste and matching of the firing shrinkage of the alumina to that of the W matallized conductor. The crackless multilayer ceramic substrates are little deteriorated under the forced deteriorating conditions made by high-temperature bias test and high-temperature and high humidity bias test.抄録全体を表示PDF形式でダウンロード (4264K) -
土屋 信次郎, 寺田 修, 斎藤 実, 鈴木 寿1991 年 38 巻 5 号 p. 605-609
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーThe titanium nitride or titanium carbonitride has generally been used for the preparation of nitrogen contained TiC-Mo2C-Ni systems. However, the structure difference between TiC-TiN-Mo2C-Ni and Ti(C, N)-Mo2C-Ni cermets seems not to have been clarified. Then, the study on this subject was made, using TiC-(18, 30)mass%TiN-20 mass%Mo2C-20 mass%Ni and Ti(C0.7N0.3) or Ti(C0.5N0.5)-20 mass%Mo2C-20 mass%Ni cermets. The following results were thought to be of great importance. The structure became finer in both cermets with increasing nitrogen content and the structure of (TiC+TiN) based cermets was considered to be finer than that of Ti(C, N) based cermets. In the former cermets, coarse carbides and carbonitrides (called CSS), and extremely fine carbides and carbonitrides (called EFC) co-excited in the structure. The average grain size of those cermets was controlled by the amount of CSS and EFC.抄録全体を表示PDF形式でダウンロード (2991K) -
寺田 修, 土屋 信次郎, 鈴木 寿1991 年 38 巻 5 号 p. 610-613
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーIt has been known that the plate-shaped titanium carbides (TiC) frequently appeared in carbides of TiC-Mo2C-Ni alloy. The study of formation of the plate-shpaed TiC has been made.
It was found that the starting TiC powder fractured along (002) cleavage plane of TiC crystal during ball-milling, resulting in the (TiC+Mo2C+Ni) mixture containing plate-shpaed TiC particles. It was also found that the formation of plate-shaped TiC in carbides of the alloy was due to the fact that the plate-shaped TiC particles were rapidly occluded by so-called surrounding structure at the initial stage of sintering.抄録全体を表示PDF形式でダウンロード (3955K) -
駒井 正雄, 岡山 浩直, 高木 研一, 渡辺 忠雄1991 年 38 巻 5 号 p. 614-620
発行日: 1991/07/25
公開日: 2009/12/04
ジャーナル フリーRecently the particle analysis of hard materials with complex phases, such as cemented carbides and Mo2FeB2 base hard alloys, has been performed by using an image analyzer. But a conventional algorithm of the image analysis has some difficulties to get accurate measurements of the microstuructural parameters, such as a mean particle size, contiguity and aspect ratio of hard partcles. To solve this problem, a new algorithm for grain boundary detection has been developed by using a back-scattered electron image, which shows electron channeling contrast (ECC) depending on the crystal direction difference in the aggregated hard particles. By applying this method to the Mo2FeB2 base hard alloys, it is quantitatively elucidated that the transverse rupture strength (TRS) drop at lower sintering temperature is due mainly to the coalescence of the hard particles.抄録全体を表示PDF形式でダウンロード (7362K) -
渡辺 忠雄, 岡山 浩直, 駒井 正雄, 高木 研一, 近藤 嘉一1991 年 38 巻 5 号 p. 621-626
発行日: 1991/07/25
公開日: 2009/12/04
ジャーナル フリーA ring on block type Ogoshi wear test was conducted in air to study the dry sliding wear behavior of both Mo2FeB2 base cermets against various alloy steels and the mating materials (alloy steels) compared with those of cemented carbides.
The main results obtained were as follows:
(1) Both the boride cermets and cemented carbides against, SUJ2 and SKH3 were less worn than SKD11 and SUS440C. The boride cermets yielded less wear of all tested mating materials than cemented carbides.
(2) The wear behavior of the boride cermets against SKD11 and SUS440C showed the non-adhesive wear (oxidative wear) up to the sliding velocity of 0.94 m/s, thereafter it changed to the adhesive wear.
(3) The wear behavior of the cemented carbides against SKD11 and SUS440C showed the non-adhisive waer at the velocity of 0.62 m/s and the severe wear above the velocity of 0.94 m/s, where the wear rate of not only mating materials but also the cemented carbides drastically increased.
(4) Against SKD11 and SUS400C an increase of the wear rate of both the cermets in adhesive range was thought to be attributed to the self mated wear caused by the adhesion of the mating materials to the counterspecimens.抄録全体を表示PDF形式でダウンロード (3987K) -
斎藤 勝義, 寒川 喜光, 飴山 惠, 金子 泰成1991 年 38 巻 5 号 p. 627-629
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーA testing of ceramics injection molding of alumina powder using a PE (polyethlene)-PP (polypropyrene)-peanut oil binder system was carried out. When the green parts were immersed in an acetone solvent at 23°C for 6 hr, the 78% of peanut oil was extracted. The residual parts were debound in air at 420°C for 2 hr. The heating rate was 2.5°C/min in the temperature range from room temperature to 50°C, and 100°C/hr from 50°C to 420°C. The debound parts were sintered at 1620°C in air for 2 hr. The relative density of the sintered specimen was 99% over.抄録全体を表示PDF形式でダウンロード (158K) -
黒木 英憲, 藤沢 伸也1991 年 38 巻 5 号 p. 630-634
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーThe dimensional changes during compacting and sintering were measured. Less than 5 mass% of copper was added to the Hoeganaes NC100.24 iron powder, as electrolytic powder, or as a coating by the substitution-precipitation process, or as 20 mass%Cu Distaloy powder. They were further mixed with 0.7 mass% of zinc stearate and pressed under 490 MPa to form compacts 10 mm in diameter and 10 mm in height. The compacts were dewaxed by heating at the rate of 50 K/min up to 873 K, being held for 30 min, and sintered successively by heating at the rate of 30 K/min up to 1398 K and being held for 30 min in dissociated ammonia.
No effects of techniques for copper addition were found on the spring-back during compacting. The dimensional changes obtained after sintering generally indicated a tendency to expansion with an increase in the copper content. The coated powder had an almost constant difference between the dimensional changes in the compacting and in the lateral directions, though the mixed powder had an increasing tendency to expansion with an increase in the copper content in the compacting direction.抄録全体を表示PDF形式でダウンロード (3701K) -
河合 伸泰1991 年 38 巻 5 号 p. 636
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (45K) -
堀 茂徳1991 年 38 巻 5 号 p. 637-642
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーThe paper were reviewed recent researches of parameters which control the flow and ductility of micrograin superplastic materials. Particular attention was emphasized to the strain rate sensitivity of the flow stress, m and high rate superplasticity. It has been pointed out that the origin of these characteristics is the grain boundary sliding process, which will be controlled by diffusional processes. It was discussed that the contribution of grain boundary sliding is more for the deformation having larger m value. The dependence of m value on effective stress / mean flow stress is similar to the dependence of m value on ∈gbs / ∈t. This suggests that the effective stress has a strong contribution for grain boundary sliding or related strain accommodation process. Favorable structure for the industrial application of superplastic forming will be also discussed. Those are in the relatively high deformation rate of optimum condition and having a high temperature stability of the structure.抄録全体を表示PDF形式でダウンロード (337K) -
Fumihiro Wakai1991 年 38 巻 5 号 p. 643-649
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーSuperplastic elongation of fine-grained ceramics can be observed when some mechanical and microstructural requirements are satisfied at appropriate test conditions, temperature and strain rate. The phenomenon can be utilized in superplastic forming, solid-state bonding, sinter-forging, hot press, and hot-isostatic pressing. Recent advances in ceramic processing brought about not only superplastic structural ceramics (ZrO2, Al2O3, mullite, Si3N4. SIC and their composites), but also superplastic functional ceramics which have characteristic properties such as electronic, magnetic, optical, chemical or biological properties. Numerous works on superplasticity of ZrO2 ceramics since 1985 revealed some characteristics of superplasticity, microstructural feature, and possible mechanisms. Attempts to achieve high-strain rate superplasticity in ceramics were performed by modifying the nature of grain boundary.抄録全体を表示PDF形式でダウンロード (3625K) -
木村 敏郎, 西野 良夫, 山内 徹, 安在 克章1991 年 38 巻 5 号 p. 650-655
発行日: 1991/07/25
公開日: 2009/12/04
ジャーナル フリーTitanium alloy GT33 was designed by NRIM to have good superplasticity at working temperature and superior mechanical properties at service temperature.
We examined the processing characteristics, the mechanical properties and the superplastic behavior of P/M GT33 alloy. GT33 alloy powder was made by plasma rotary electrode process and equipment was improved to produce fine and rapidly solidified powder. Mean particle diameter was decreased from 180μm to 85μm and cell size was decreased from 6μm to 1μm. The flow stress of HIP'ed preforms became to half of original one and superplastic elongation was doubled. HIP'ed GT33 preforms were successfully forged superplastically to φ400mm fullscale model disc with twisted blades (blisc). The forged and double solution heat treated GT33 alloy showed a high strength to density ratio at 300°C up to 28.6×106mm with 11.3% elongation.
Furthermore, 'dual property disk' which shows high strength at boss portion and high creep resistance at rim was made by partial hydride-dehvdride Process.抄録全体を表示PDF形式でダウンロード (6203K) -
安田 健, 岡山 昭, 児玉 英世, 諏訪 正輝1991 年 38 巻 5 号 p. 656-659
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーIn order to make clear relationship between high temperature tensile properties and fine microstructure of rapidly solidified cast-type Ni-base superalloys without heat treatment required for consolidation process, tensile test was carried out by changing strain rate from 5×10-5 s-1 to 2×10-2 s-1 and test temperature from 900°C to 1050°C using IN738LC and Rene'80 melt-spinning ribbons by twin roll process which were superior to ribbons by single roll process from the viewpoint of structure homogeneity. The dependence of tensile strength on strain rate and test temperature was studied and strain rate sensitivity, m, were estimated from tensile test results. From this study, it was found that tensile strength was influenced by γ' particle diameter, test temperature and strain rate, and "m" of ribbons exhibited above 0.3 over 950°C.抄録全体を表示PDF形式でダウンロード (4992K) -
安田 健, 小林 満, 児玉 英世, 諏訪 正輝1991 年 38 巻 5 号 p. 660-663
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーThe superplasticity of rapidly solidified cast-type Ni-base superalloy melt-spun ribbons which have columnar grains was investigated. Melt-spun ribbons, about 80μm in thickness, were made by a twin roll process. Superplasticity was investigated in terms of peak flow stress, elongation of specimens, and strain rate sensitivity "m" by tensile tests carried out various strain rates at 1000°C and 1100°C. The maximum m was found to be about 0.70 and its maximum elongation was larger than 360%. (360% is limit of tensile test machine used in this study.) The microstructure of specimen after high temperature tensile test was observed, and still composed of columnar structure. From these results, it was found that fine columnar structure materials exhibited superplasticity as well as equi-axial grain structure in special conditions.抄録全体を表示PDF形式でダウンロード (5888K) -
馬渕 守, 東 健司, 岡田 義浩, 谷村 眞治, 今井 恒道, 久保 勝司1991 年 38 巻 5 号 p. 664-667
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーSuperplastic behavior in Si3N4 particulate reinforced 606lAl matrix composite has been investigated in a constant strain rate tension test. The particulate composite was processed with hot extrusion at 773K with a reduction ratio of 100, and the as-extruded composite was tested at 818K. As a result, the particulate reinforced composite showed small elongation of 50% at low strain rate of 10-4s-1, however, total elongation increased with strain rate, and the composite showed large elongations of more than 400% at high strain rates of 10-1-100s-1. The composite showed low m value of 0.1 at less than 10-2s-1, which corresponds to low elongation, however, showed high m values of more than 0.3 at more than 10-1s-1. The grains of the composite after annealing at 818K were less than 3μm and subgrain structure was observed in the grains. Grain boundary sliding pattern was observed on the surface of the specimen deformed superplastically. Superplastic deformation is probably due to the grain boundary sliding.抄録全体を表示PDF形式でダウンロード (2197K) -
沖本 邦郎, 佐藤 富雄, 松山 博進, 岡 三嘉1991 年 38 巻 5 号 p. 668-672
発行日: 1991/07/25
公開日: 2009/12/04
ジャーナル フリーComposites are fabricated from Zn-22Al base superplastic pre-alloy powder mixed individually with K2O-6TiO2, Al2O3, ZrO2 and SiC powders (or whiskers) to improve mechanical strength of the Zn-22Al base powder compacts. Effects of mixing ratio, mixing time and forming temperature on strength of the composites are investigated and densification behaviour of the composites is compared to that of a magnetic composite material.
It is found that the Al2O3 powder has good suitability for the Zn-22Al base superplastic powder and the moderate mixing ratio of the Al2O3 powder is 15wt%. Maximum ring crushing strength of the composites made by Zn-22Al-1.OCu-0.03Mg superplastic powder mixed with the Al2O3 powder of 15wt% reaches 655MPa under a condition of the forming temperature of 420°C.抄録全体を表示PDF形式でダウンロード (4518K) -
沖本 邦郎, 佐藤 富雄, 松山 博進, 岡 三嘉1991 年 38 巻 5 号 p. 673-680
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーA magnetic composite material is fabricated from Zn-22A1 base superplastic pre-alloy powder and ferromagnetic one. A problem yet to be solved in the magnetic composite material is to improve magnetic characteristics and mechanical properties of the material. Then in this research, it is carried out to find the optimum forming conditions for improving the mechanical properties of the material. For this purpose, it is investigated with regard to the fabrication factors such as mixing process and forming temperature. Also dimension and the magnetic characteristics of the material are investigated. It is found that crushing strength of the magnetic composite material made by Zn-22Al-1.0Cu-0.03Mg pre-alloy powder mixed with strontium ferromagnetic powder of 50wt% reaches 157MPa under the condition of the forming temperature at 420°C and forming pressure of 300MPa.抄録全体を表示PDF形式でダウンロード (4226K) -
菖蒲 一久, 渡辺 忠彦, 谷 英治1991 年 38 巻 5 号 p. 681-684
発行日: 1991/07/25
公開日: 2009/12/04
ジャーナル フリーHigh temperature creep deformation of glass phase containing MoSi2 sintered compacts has been studied and following results were obtained:
1) Creep transients of normal type were observed.
2) Microstructural observation revealed that the principal mechanisms of deformation involved grain boundary sliding, viscous flow of glass phase, and diffusion through glass phase.
3) Transition of stress dependence of deformation was observed to occur around 10MPa. The stress exponent appears to approach three for low stresses, and one for high stresses. This can be attributed to the alteration of rate-controlling mechanism from grain boundary slinding to viscous flow with increasing stress.
4) It was speculated that grain boundary sliding has the stress exponent of three for low angle and coincident boundaries, and two for high-angle random boundaries.抄録全体を表示PDF形式でダウンロード (1458K) -
千徳 英一, 岩松 基茂, 柏本 浩伸, 藤村 善雄1991 年 38 巻 5 号 p. 685-688
発行日: 1991/07/25
公開日: 2009/12/04
ジャーナル フリーGlass ceramics consisting of fluor-phlogopite can be machined with tight tolerance with conventional metal working equipments and tools. These ceramics are used for a few mechanical and electronic parts. The purpose of this paper is to study bonding material of diffusion bonding and to find the mechanism of bonding with high efficiency. The tests of diffusion bonding were conducted on a electric furnace and heating temperature was varied from 1100 K to 1300 K. The main results obtained are as follow: (1) The bonding strength of machinable ceramics has a great influence heating temperature and time. (2) The high pressure of boundary surface in the diffusion bounding was increase bonding strength. But, bonding strength was held constant at pressure above 0.08 Mpa. (3) The bonding material of boric acid-solution was possible to obtain a high bonding strength at short time.抄録全体を表示PDF形式でダウンロード (3493K) -
押出成形法による高速度工具鋼中窒素材の製造と特性中村 秀樹, 持田 洋一1991 年 38 巻 5 号 p. 689-693
発行日: 1991/07/25
公開日: 2009/05/22
ジャーナル フリーA new production process of sintered hollow high speed tool steel bar blanks by binder-assisted powder extrusion method has been developed. This technology is mainly applied to produce hollow bar blanks for oil hole drills, taps and punches. Further it is applicable to produce highly alloyed solid bar blanks which are not able to be produced by hot forging or rolling. Materials made by this process show virtually full density only by sintering and their microstructures are as fine as gas atomized and HIP processed materials. Mechanical properties of these materials are almost as same as those of gas atomized and HIP processed materials because of their fine mictostructures.
The cutting performance of AISI T15 oil hole drills made of the sintered hollow blanks showed approximately 1.5 times better than that of conventionally processed AISI M 2 oil hole drill.
The optimum powder characteristics for binder-assisted powder extrusion and properties of sintered blanks by this process are reported.抄録全体を表示PDF形式でダウンロード (3184K)
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