巻号一覧
6 巻 (1959)
- 6 号 p. 213-
- 5 号 p. 181-
- 4 号 p. 149-
- 3 号 p. 91-
- 2 号 p. 45-
- 1 号 p. 1-
6 巻, 3 号
選択された号の論文の3件中1～3を表示しています
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西島 寅次1959 年 6 巻 3 号 p. 91-98
発行日: 1959/06/25
公開日: 2009/05/22
ジャーナル フリーTorajiji Nishijima : 1 Sintering of Iron Powder Compacts. 1. 3. Changes of Pores in Powder Compacts during Sintering. In this paper, pore changes in powder compacts during sintering were studied. Before sintering, voids between powder particles meant to pores, but after sintering, crystal grain growth among particles were progressed, so voids were included inter or inner crystal grains. In old times, it was considered that pores became to be spherical shape, and disappered at last. But in reality, even if sintered for longer time, it was difficult for pore to be disappered. And then it's found that pores were settled to some negative crystal shape based upon the crystallographical characteristics of the back ground. (for example, octahedral shape of pores were found in tungsten powder compacts.)
On the other hand, if powder compacts composed of mixtures were sintered at some higher temperature than the melting point of one of components, and if all of the liquid phase did not be alloyed, pores became to be disappered after longer heating [for cxample, such a fact was gained by heating the iron and copper (5-40%) powders mixture at 1100°C.] But if all of them were alloyed into solid solution, small pores used to stay, just like in the case of powder compacts composed of single component. [example ; by heating the copper and tin (10%) metal powders mixture. at 800°C.] Also it's revealed that at the first stage of heating above the melting point of one of components, coarse pores used to be prepared by the penetration of liquid phase among solid powder particles. The grades of these pores size were especially depended on the grades of powder size to be molten. It'll be a convenient structure to get good self-oiling ability of the oilless bearing.抄録全体を表示PDF形式でダウンロード (9499K) -
堤 禎章, 今西 国三, 清水 哲1959 年 6 巻 3 号 p. 99-104
発行日: 1959/06/25
公開日: 2009/05/22
ジャーナル フリーCutsomary, friction plate of friction iron props in mines have been made of aluminium alloy. They have ideal characteristic, but the specific corrosions of aluminium alloy occures hard in Japanease mines that have much salt and are high moisture, moreover they catch fire when props are pulled out. Hence, 18-8 stainless steel, 18-8 stainless steel metalliconed zinc and hard copper alloy have been researched, but their characteristics are worse than aluminium alloy's. Namely the iron props that use 18-8 stainless steel friction plate have rigidity, that use copper alloy friction plate have contructibility, wherefore the great factor that exert an influence upon decent characteristic is young's modulus and friction factor. The friction factor between iron props and friction plate, and constricting pressure of cotter control the load that decent of iron props starts. If constricting pressure of cotter is constant, friction factor will exert an influence upon a clamping load. The other necessary material characteristics for friction plate are that plate don't melt and stick to iron props at high pressure, anticorrosion, antiflash, compressive strength and wear resistivity. Generally, the young's modulus of metal sintered products is influenced by its density and the amount of the second phase of its materials. In the experiment, we mixed iron powder and copper powder at excess rate and made sintering alloys, for making to be decreased the young's modulus and a friction factor of iron alloy. By measuring their young's modulus and friction factor (at high pressure), we selected the composition that indicated the near property to aluminium alloy. We use it as friction plate of iron props in a mine practically and find that it indicaded the ideal characteristic. Hence we report that result.抄録全体を表示PDF形式でダウンロード (1484K) -
小笹 稔1959 年 6 巻 3 号 p. 105-121
発行日: 1959/06/25
公開日: 2009/12/04
ジャーナル フリーBy carbon replica method, an observation was made, under electron microscope, of the shape, surface condition and the state of aggregation of the particles of W and Mo powders prepared by hydrogen reduction.
As a result, it wass observed that the primary particles of W less than 0.2μ in diameter were of sphere form and, of larger diameter, of well developed crystal form. On particles of over 2μ in diameter, a lot of octahedral and rhombic dodecahedral particles were observed and some of them looked like cubic particles. At high reduction temperature, dumbbell-shaped particles were observed, primary particles of Mo also showed similar crystal shape when the particle diameter exceeded 1μ.
Immediately after the powder is being reduced, the surface of particle was relatively smooth, but when oxidized, small projections or needle oxide were observed on it. On the surface it was also observad that the doping materials were deposited.
When the primary particles were small they were linked with each other, resulting formation of aggregates, which resembled in shape with original crystals of their mother salts. As the size of the primary particles increased over 2μ, the aggregate lost their original shape.
Doping materials affect the growth of particlces, and as a result of observation it was found that the size of undoped particles is almost uniform and that KC1 has little effect on the size of particles but K2O⋅2SiO2 doped particles results in large and small particle sizes and Al2O3 or TnO2 retards the particle growth. When KCl, K2O⋅2SiO2 and Al2O3 are used at the same time that cause spread in the distribution. It was learned by etching the particles that primary particles observed by electron microscope were substantially single crystals.抄録全体を表示PDF形式でダウンロード (26349K)
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