巻号一覧
33 巻, 3 号
選択された号の論文の9件中1～9を表示しています
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久米 昭一1986 年 33 巻 3 号 p. 105-110
発行日: 1986/04/25
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (393K) -
久野 洋, 今井 宏明1986 年 33 巻 3 号 p. 111-115
発行日: 1986/04/25
公開日: 2009/05/22
ジャーナル フリーCompaction process of granules was studied by compressing a granule bed with a constant rate increase of applied stress. Compaction process at the lower range of applied stress proceeded with the decrease of intergranular void volume. The change of the intergranular porosity, εi was expressed as
In (εio/εi)=(P/Pc) In (εio/εif)
in the stress range from 0 to Pc, where P is applied stress, εio is the initial intergranular porosity and εif is the intergranular porosity at Pc. Pc was nearly proportional to the granule strength, Pg and expressed by (I -εif) Pa.抄録全体を表示PDF形式でダウンロード (1310K) -
渡辺 龍三1986 年 33 巻 3 号 p. 116-120
発行日: 1986/04/25
公開日: 2009/05/22
ジャーナル フリーQuantitative stereological measurement was done on the structural evolution in Fe-20wt%Cu powder compact during hydrogen sintering in the presence of a liquid phase. Many structural parameters pertaining to skeletal structure of solid particles, as well as to pore structure, were found to follow simple kinetics. The porosity, inner free surface and pore number decreased exponentially with sintering time. The mean particle intercept, particle number, and the size and number of interparticle welds followed simple power functions of sintering time. A geometrical similarity of the skeletal structure of solid particles remained throughout the sintering period. The kinetics of pore elimination was analysed using the stereological data of the residual pores. Hydrogen diffusion through liquid phase was considered to be the rate-determining step of the pore elimination.抄録全体を表示PDF形式でダウンロード (1489K) -
黒木 英憲, 船引 真1986 年 33 巻 3 号 p. 121-126
発行日: 1986/04/25
公開日: 2009/05/22
ジャーナル フリーThe change in dimensions of some atomized powder compacts, 10φ×h10 mm in size, was measured with a micrometer during the production process, after pressing at 2-8 t/cm2 (196-784 MPa), after de-waxing at 500°C (773 K) for 30 min, and after sintering at 900°C (1173 K) for 5180 min. Cubes, 10 mm in size, of the compacts were also prepared as above, and used for the dilatometry.
No relation was found between the sum of the expansion by spring-back and de-waxing, and the shrinkage during sintering. A remarkable swelling appeared during de-waxing and initial sintering in atmospheres containing H2 regardless of the content of the powder lubricant. This is probably due to the pressure of the water vapour formed in reducing the oxide. Although the swelling was larger in the pressing direction than in any others, the shrinkage during sintering after the swelling was almost isotropic. The swelling seems to be the major cause of the anisotropy in the dimensional changes obtained from the sizes of green and sintered compacts.抄録全体を表示PDF形式でダウンロード (453K) -
金 〓彩, 渡辺 〓尚1986 年 33 巻 3 号 p. 127-131
発行日: 1986/04/25
公開日: 2009/12/04
ジャーナル フリーPhenomena appearing during sintering process of an iron-1.0wt%tin mixed powders compact were investigated in comparsion with those of the iron powder compact. The results obtained are as follows;
When the iron-tin mixed powders compact is being heated, tin powder particles become liquid at the melting-point of tin, 505 K (232°C). The tin-liquid penetrates into capillaries between iron powder particles above about 673 K (400°C) and with the rising of temperature up to about 1173 K (900°C), the tin-liquid forms various tin-iron intermetallic compounds; θ, η, ε and ζ by the dissolution with a little of iron powder and also, these compounds produce their respective transient liquid phases by the decomposition of themselves. The above phenomena make the compact have a lower strength as well as more expansion in comparison with those of iron powder compact.
When the temperature is above about 1273 K (1000°C) however, all the intermetallic compounds become α phase iron-tin solid-solution having higher self-diffusion coefficient than the γ phase. The above phenomena make the compact have a higher strength as well as more shrinkage in comparsion with those of iron powder compact at the sintering temperature of about 1423 K (1150°C).抄録全体を表示PDF形式でダウンロード (2659K) -
三浦 秀士, 酒田 修, 徳永 洋一1986 年 33 巻 3 号 p. 132-138
発行日: 1986/04/25
公開日: 2009/05/22
ジャーナル フリーIn order to improve the ductility and toughness of high strength sintered alloy steels, an austemper heat treatment was applied to Fe-2%Si-3%%Ni-0.3-0.5%C compacts sintered at 1250°C for various time in vacuum. In addition to tensile strength and elongation the dependence of impact strength on testing temperature for austempered Si-Ni steel compacts are investigated, and the correlation between the retained austenite and the properties is discussed. The results are summarized as follows:
Mixed structure of upper bainite and retained austenite is produced by austempering (400-500°C) the Si-Ni steel compact, which shows the more excellent properties than those of conventional sintered alloy steels, especially the value of elongation increases with increasing the amount of retained austenite.
The ductile-brittle transition temperature is considerably lower and the impact strength at room temperature is higher for the austempered compact than for the compact sintered alone. The reason for this may be attributed not only to the existence of retained austenite but to the transformation plasticity induced by the retained austenite.
Also, it is found that the mechanical properties of austempered compacts are remarkably improved by the sintering conditions. It is therefore expected that the properties of the same level as the conventional sinter-forged steels are attainable, when the uniform distribution of alloying elements and the reduction of finer pores are achieved for Si-Ni steel compacts by such a high-temperature and a long-time sintering.抄録全体を表示PDF形式でダウンロード (5210K) -
小原 嗣朗, 立沢 清彦1986 年 33 巻 3 号 p. 139-144
発行日: 1986/04/25
公開日: 2009/05/22
ジャーナル フリーMechanical properties of Fe-Cu alloys sintered by using atomized and carbonyl iron powders plated with copper were studied. The sintered alloys with atomized iron powder showed higher tensile strength and elongation than those of sintered alloys with mixed powder. The sintered alloys with carbonyl iron powder showed the tensile strength of the same levels as the Fe-Cu wrought materials of identical composition, and the elongation of two times larger than that of the wrought alloys. Furthermore, the tensile strength and the elongation of these alloys can be altered in wide range by heat treatments after sintering, that is, quenching and aging.
These sintered alloys have the nonequilibrium microstructure consisted of two regions, that is, higher and lower copper content regions. The former is the intergranular region in the case of atomized iron powder, and the region around pore in the case of carbonyl iron powder. The latter is the central portion of large iron particles in the case of atomized powder, and the matrix region in the case of carbonyl powder. This nonequilibrium structure in the Fe-Cu alloys sintered with plated powder gives rise to the high tensile strength and the large ductility.抄録全体を表示PDF形式でダウンロード (3409K) -
真島 一彦, 北垣 克, 山本 光政, 庄司 啓一郎1986 年 33 巻 3 号 p. 145-152
発行日: 1986/04/25
公開日: 2009/05/22
ジャーナル フリーUsing three different kinds of mixed powder compacts; each composed of Ti+TiAl3+(Al-50V), Ti+ A1+(Al-50V) and Ti+TiAl3+V, the sintering behavior of Ti-6A1-4V ternary system was investigated mainly through dilatometric method and EPMA, in relation to an α2 phase.
The results obtained are summarized as follows:
(1) The α2 phase was observed to have widely developed in all of the above mentioned three specimens; at 1373 K during heating process.
(2) This α2 phase has disappeared by the diffusional process in both Ti + TiAl3 + (Al-50V) and Ti + Al + (Al-50V) specimens after sintering at 1373 K for 3.6 ks, however in the Ti +TiAl3+V specimen, small amount of remaining α2 phase was observed.
(3) The sintering conditions necessary to obtain homogenized structure were confirmed to be 1373 K×3.6 ks, 1473 K×3.6 ks and 1573 K×3.6 ks in the following order: Ti+TiAl3+(Al-50V), Ti+AI+(Al-50V) and Ti+TiAl3+V specimens.抄録全体を表示PDF形式でダウンロード (7451K) -
鈴木 寿, 松原 秀彰, 斉藤 武志1986 年 33 巻 3 号 p. 153-156
発行日: 1986/04/25
公開日: 2009/05/22
ジャーナル フリーThe load (p) -deflection (d) curves, creep curves and transverse-rupture strength of Ti(C, N)-Mo2C-Ni alloys were examined at 1273 K as functions of nitrogen content, particle size of carbonitride and domain size of binder. The deformation of the alloy at low stress level was suppressed greatly with increasing the nitrogen content and slightly with decreasing the particle size. However, the apparent deformation at high stress level was enhanced with decreasing particle and domain sizes in particular in the alloys containing nitrogen. It was noted that the high temperature transverse-rupture strength, creep rupture time, etc. were closely related to the apparent deformation.抄録全体を表示PDF形式でダウンロード (1977K)
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