巻号一覧
20 巻, 6 号
選択された号の論文の5件中1～5を表示しています
- |<
- <
- 1
- >
- >|
-
高見沢 秀男1973 年 20 巻 6 号 p. 171-177
発行日: 1973/12/25
公開日: 2009/05/22
ジャーナル フリーY free polycrystalline garnets, which composition is given by the formula Ca3-yBiyFe3.5-0.5x+0.5y GexV1.5-0.5x-0.5yOi12, are synthesized with standard ceramic techniques.
The materials whose Tc are higher than that of Al-substituted YIG for the same 4πMs (≤800G) and dH values can be obtained. The Ge 4+ ion substitution reduces the porosity with 0≤x≤0.3 and decreases the anisotropy constant K 1 with x≥0.5 since a part of Ge 4+ ions enter into 16a sites of garnet structure. Only 25% of entire ΔH of the garnets with 0≤x≤0.3 are due to anisotropy broadening according to the spinwave theory using observed K 1/Ms values of single crystals.
Using proper hot-pressing techniques, the porosity can be reduced to nearly zero. Small linewidth materials with ΔH=12Oe and ΔH=6Oe are obtained with the composition of (x=0.3, y=0.2) and (x=0.5, y=0.2), respectively.抄録全体を表示PDF形式でダウンロード (4697K) -
三谷 裕康, 永井 宏1973 年 20 巻 6 号 p. 178-183
発行日: 1973/12/25
公開日: 2009/05/22
ジャーナル フリーThe sintering process of Al-Cu 4wt% binary mixed powder compacts was investigated by the vertical dilatometer. The compacts expand rapidly with large pore generation at the eutectic temperature of 548°C. The amount and velocity of the expansion depends considerably on the sintering temperature, compacting pressure and particle size. However, the amount of the shrinkage does not depend on the compacting pressure and particle size, but on the sintering temperature or the amount of the liquid phase.
In order to observe the process of the expansion and pore generation plainly, the synthetic sintering experiments using the pressed wire model with 0.16 mmφ Al wires and 0.15 mmφ Cu wires were carried out at 600°C. Cu penetrates rapidly in the horizontal direction against the compacting direction. However, the amount of the expansion in the compacting direction is much larger than in the horizontal direction. On the other hand, the pores are not observed at the initial positions of Cu wires, but at the boundaries between the Al wires in which Cu diffused and those in which Cu didn't diffuse.抄録全体を表示PDF形式でダウンロード (3426K) -
小原 嗣朗, 立沢 清彦1973 年 20 巻 6 号 p. 184-189
発行日: 1973/12/25
公開日: 2009/05/22
ジャーナル フリーThe effect of repeated transformation on sintering rate of iron powder compact has been investigated. Iron powder compacts were sintered under small compressive load by cycling temperatures from 25°C below to 25°C above the a ?? γ transformation temperature of iron (910°C), with various lengths of cycle and loads. The sintering rate was markedly accelerated by repeated transformation during sintering, compared with isothermal sintering. The shrinkage of compact in this repeated transformation sintering was dependent on the number of cycles, and the relationship between the shrinkage by transformation and the number of cycles was represented by a formula
S=AN
where S was the shrinkage of compact, N, the number of cycles, and A, a constant. It was concluded that the acceleration of sintering rate was due to the enhanced pore elimination by the transformation softening, that is, superplasticity occurred during the α ?? γ transformation.抄録全体を表示PDF形式でダウンロード (436K) -
鈴木 寿, 棚瀬 照義, 林 宏爾1973 年 20 巻 6 号 p. 190-193
発行日: 1973/12/25
公開日: 2009/05/22
ジャーナル フリーEffects of e' phase, carbon and Fe contents on the corrosion resistance of WC-Co cemented carbide in acidic solutions were investigated. The WC-10% Co alloys with various carbon and Fe contents were sintered at 1375°C for 1 to 1.5 hrs. The ε' phase was formed by grinding the surface of specimens.
Results were as follows: (1) The corrosion resistance of the alloy was decreased with increasing carbon and Fe contents, as has been reported previously. In addition, it was found that the a' phase is harmful for the corrosion resistance in every case, in particular in the case of high carbon alloys. (2) The corrosion front was almost flat in two phase alloy, even in the alloy with a small amount (<-0.2%) of Fe. On the contrary, that of three phase specimen with free carbon showed ruggedness. This phenomenon was more marked with increasing Fe contents. These rugged fronts seemed to be due to precipitation of the iron compound in addition to the free carbon. (3) Residual stresses in the surface layer due to grinding did not affect the corrosion resistance, which was confirmed using specimens containing Fe more than about 0.6%, where in this case the transformation, γ→ε', does not occur.抄録全体を表示PDF形式でダウンロード (4257K) -
岡本 明, 田村 秀夫, 吉田 哲郎1973 年 20 巻 6 号 p. 194-195
発行日: 1973/12/25
公開日: 2009/05/22
ジャーナル フリーPDF形式でダウンロード (2070K)
- |<
- <
- 1
- >
- >|