巻号一覧
8 巻 (1961)
- 6 号 p. 247-
- 5 号 p. 183-
- 4 号 p. 137-
- 3 号 p. 101-
- 2 号 p. 43-
- 1 号 p. 1-
8 巻, 2 号
選択された号の論文の5件中1～5を表示しています
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三谷 裕康1961 年 8 巻 2 号 p. 43-48
発行日: 1961/04/25
公開日: 2009/05/22
ジャーナル フリーIt is well known that an abnormal expansion appears in Cu-Sn compacts during sintering. For the purpose of investigating the cause of this phenomenon, author carried out the dilatometric study on kinetics of sintering with Cu-Sn compacts containing about 10% Sn powder and 0.5% Zn-stearate.
Results obtained in this experiment were as follows ; the abnormal expansion appeared always at 798°C, which is the highest peritectic temperature in the Cu-Sn equilibrium diagram, and this expansion increased with increase of heating-rate ; from the microscopic examination, it is presumable that right below the peritectic temperature large amount of liquid phase regions accompanied by the β-phase regions were retained in the compact, however, just at this temperature or above, the β-phase must decompose to the α and liquid phase, subsequently the direct contact with the α-phase accelerates the diffusion of the liquid phase, consequently the liquid phase rapidly disappered above the peritectic temperature on heating ; the absorbed gas in the liquid phase was discharged by rapid solidification at 789°C, showing the dilatometric expansion and the enlarged porosity, judging from the following examination of gas atmosphare, the greater part of the absorbed gas can be estimated as H2.
In order to eliminate the abnormal expansion, slow heating and, isothermal keeping right below the peritectic temperature are recommendable.抄録全体を表示PDF形式でダウンロード (1993K) -
久保 輝一郎, 谷口 雅男, 白崎 信一1961 年 8 巻 2 号 p. 49-57
発行日: 1961/04/25
公開日: 2009/05/22
ジャーナル フリーFerric oxide powders were prepared by roasting of ferrous sulphate crystals in air at various temperatures and heating periods ranging from 630°to 800°C, 15-30 hrs respectively. Ferrous sulphate crystals used as raw material were obta-ined by crystallization from pickling liquor and waste sulfuric acid sulution by-produced in the process of titanium dioxide production from ilmenite ore (P and I denote for each specimens prepared by roasting of ferrous sulphate crystals obtained in the former and the latter processes respectively).
The physico-chemical properties of ferric oxide powders were examined by means of chemical and spectral analyses, X-ray diffraction and electron microscopy, measurements of specific gravity, specific surface area, particle size and especially dissolution rate in dilute hydrochloric acid solution.
The results were as follows. (1) Purities of P and I specimens are about 99. 0 and 95.0% as ferric oxide respectively, which contain Mn, Cu, Zn, Ti, Al, Mg, Pb, Si probably as oxides and both specimens give X-ray diffraction of a-Fe2O3 and irregular particle shape in electron microscopic photograph. (2) Values of specific gravity, specific surface area and particle size of each specimen are dependent upon their thermal histories as previously reported. (3) Though dissolution rate of ferric oxide powders in dilute hydrochloric acid solution also depends on their roasting conditions, the ratios of these values to their specific surface areas are almost constant for both P and I specimens except the I specimen prepared by roasting at 630°C for 16 hrs, which gives about two times surface activity per unit area in dissolution rate compared with the remainder.抄録全体を表示PDF形式でダウンロード (1897K) -
木村 康之1961 年 8 巻 2 号 p. 58-62
発行日: 1961/04/25
公開日: 2009/05/22
ジャーナル フリーA very dense form is produced when metallic oxide powders are formed by explosives. In this study, basic research on the method of explosive forming of metallic oxides was carried on while measuring a few properties of the formed samples and these were compared with properties of sample produced by static pressure. The explosive used in this experiment was T.N.T. and its form is shown in Table (1). Metallic mould used for forming samples is as shown in Fig. 1 and the metallic mould and explosive were arranged as shown in Fig. 2. The followings were made clear as a result of a few measurements made on samples produced by explosive forming.
(1). The surface hardness Hv of ZnO+Fe2O3 sample after forming is as shown in Table (2). The micro-Vickers hardness Hv of sample formed by 360kg/cm2 static pressu-re was 3.16 while the Hv of sample formed by using 30g of T.N.T. was 20.9.
(2). The density of Zn-ferrite raw material used for forming (diameter of piston used for forming was 10mm) by using 30g of T.N.T. was 3.8-4.2g/cc, which corresponds to a density of 70-80% of Zn-ferrite (Fig. 3).
(3). Of the moulds used after explosive forming, there was entirely no damage to the press cylinder in which sample was placed. However, the piston was damaged as shown in Fig. 4 and Fig. 5. The shock absorbing plate was destroyed by the detonation (Fig. 4, 6, 7, 8).
(4). The expansion-contraction characteristics when mixture of ZnO and Fe2O3, and also when CdO and Fe2O3 were formed were measured. With regards to expansion-contraction characteristics of Zn-ferrite and Cd-ferrite formed by using 30g of T.N.T., expansion at high temperature was 1-2% greater and the rate of contraction at 1400°C was approximately 10% less (Fig. 9) than those formed by static pressure.
(5). With regards to microscopic structure, the number of pores in samples formed by using 30g of T.N.T. was larger than those formed by static pressure and the shape was small. Another feature of this method is that there are small, long pores parallel with the detonated surface, as can be seen in Fig. 10.抄録全体を表示PDF形式でダウンロード (3112K) -
渡辺 〓尚1961 年 8 巻 2 号 p. 63-72
発行日: 1961/04/25
公開日: 2009/05/22
ジャーナル フリーThe results obtained were as follows :
1) At temperatures over the aFe-γFe transformation point (910°C), the inherent pores in the compact grow slightly because of the partial shrinkage accompanying the phase change of iron powders.
2) Over the melting point of copper (1083°C), the copper powders melt and spread into the inherent pores, leaving the new pores, "copper-off pores", at the site of the copper powders by the same mechanism of pore-fomation as the "tin-off pores" on Cu-Sn compact. The shapes of these new pores are similar to those of the copper powders and their sizes increase to slightly larger than those of the copper powders by corrosive action of molten copper to iron powders. At the same time the copper powders melt spread in the inherent pores also enlarges the latter by the corrosive action. Finally, the inherent pores and the new pores grow still more as a results of expansion of the compact following the alloying of iron and copper, and the sintered Fe-Cu compact holds numbers of pore necessary for a better self-lubricating action.
3) When the samples are kept at the final temperature for a long time, all the pores formed begin to shrink as a result of densification of the sintered Fe-Cu compact.抄録全体を表示PDF形式でダウンロード (5832K) -
Shiro Fujishiro1961 年 8 巻 2 号 p. 73-76
発行日: 1961/04/25
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (1123K)
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