巻号一覧
26 巻, 5 号
選択された号の論文の6件中1～6を表示しています
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三浦 秀士, 徳永 洋一1979 年 26 巻 5 号 p. 163-168
発行日: 1979/07/25
公開日: 2009/05/22
ジャーナル フリーThe authors have reported previously that the dynamic resonance means for measuring Young's modulus of sintered iron gives better accuracy and reproducibility than the mechanical testing. Inthe present paper some factors affecting the Young's modulus of sintered iron are discussed taking the pore structure into account.
Most of the specimens, 4×4×40 mm, were prepared from carbonyl iron powder, followed by compacting under 2 to 9t/cm2, presintering for 20 min at 650°C and sintering for 0 to 30 hr at 700 to 1200°C in hydrogen atmosphere.
Young's modulus of sintered iron was found to be highly dependent on the pore shape, but it was independent on the grain size, the pore size, and the preferred orientation of crystals. Since commercial sintered iron has irregular pore shape, its Young's modulus is low. To make the Young's modulus of commercial sintered iron as high as that of carbonyl sintered iron with the same density, sieved fine powder should be sintered for long time or the porosity should be lower than about 6%.
Though it has been said that the sinterability is good at high temperatures in a phase, from the point of view of core shave and its notch effect, it is no good for material nrooerties to sinter in short time, about 1 hr.抄録全体を表示PDF形式でダウンロード (2599K) -
西垣 賢一, 大沢 雄三, 土井 英和1979 年 26 巻 5 号 p. 169-173
発行日: 1979/07/25
公開日: 2009/05/22
ジャーナル フリーFor the purpose of strengthening the binder phase of TiC base cermets, we investigated the effect of 0.5-2% Al addition on mechanical and cutting properties.
The results obtained are as follows;
1) The hardness of sintered compacts increased almost linearly with Al content.
2) By means of X-ray diffraction, it was recognized that the binder phase of the alloys containing 0.5% and 1.0% Al consists of both y and γ' phases. On the other hand, in the case of 2% Al addition, the microstructure consists of only γ' phases
3) It was shown that transverse-rupture strength of the alloys drops with increase of Al content. 4) The alloy containing 1% Al showed the most excellent wear resistance in continuous steel cutting test; the result can be explained in terms of the effect of γ' precipitation hardening. While the alloy containing 2% Al showed somewhat lower wear resistance presumably because of the effect of the negative temperature dependence of the strength of γ'.抄録全体を表示PDF形式でダウンロード (3293K) -
明智 清明, 原 善四郎1979 年 26 巻 5 号 p. 174-179
発行日: 1979/07/25
公開日: 2009/12/04
ジャーナル フリーBoron fibre-titanium composite was produced by a resistance sintering process. A mixture of titanium powder (-350 mesh) and boron fibre (200, μmφ and 140 μmφ; their tensile strenghts are 320 kg/mm2 and 356 kg/mm2, respectively) was resistance-sintered with continuous or cyclic current flow in 0.6-6.0 sec. A composite resistance-sintered under an optimum condition using cyclic current flow exhibited a higher tensile strength than that of the resistance-sintered pure titanium at higher temperatures, and the fibre reinforcing effect on the tensile strength was recognized even at room temperature. When a composite was resistance-sintered with cyclic current flow, the reaction layer between boron fibre and titanium was much thinner than that formed in continuous current flow sintering. Tensile strength decreased with the increase of the thickness of boron-titanium reaction layer.抄録全体を表示PDF形式でダウンロード (4275K) -
明智 清明, 原 善四郎1979 年 26 巻 5 号 p. 180-186
発行日: 1979/07/25
公開日: 2009/05/22
ジャーナル フリーElectrical resistance of titanium and its alloys, which were resistance-sintered with various conditions, was measured. Effects of resistance-sintering condition, particle size, alloying powders etc. on the electrical resistivity p were thought to be fairly sensitive. The electrical resistance and the mechanical properties of resistance-sintered titanium depend upon the density ratio in the case of lower density ratio than 96% (theoretical), and upon the oxygen content in higher density ratio than 96% (theoretical). p of resistance-sintered titanium alloys depends upon the microstructure, and, increases with alloying, as well as the tensile strength. Electrical resistivity at the last resistance-sintering stage, ρ*, which was calculated by using the wave shapes of current and voltage measured during resistance-sintering of titanium powder, agrees with the bulk resistivity of titanium at high temperature.抄録全体を表示PDF形式でダウンロード (471K) -
大島 信正, 姫野 欣也, 谷 紀広1979 年 26 巻 5 号 p. 187-191
発行日: 1979/07/25
公開日: 2009/05/22
ジャーナル フリーA precipitation method was found to be the most available forming process of the photoconductive (PC) layer for the X-ray image converting panel made of electroluminescent and photoconductive materials, To make a homogeneous PC-layer of 300-400 μm thickness with high reproducibility, the characteristics of the PC powder materials, resin binders and solvents were investigated and optimum conditions for the precipitation were established.
The photo-sensitivity of the PC-layer increased by using a high speed stirring process, and a finer surface of the PC-layer was produced by controlling the difference of precipitation speeds between large and small PC-particles.
As a result, the quality and resolution of the converted image were improved and the possible applying voltage of the panel increased. The improved panel showed a brightness of 12-15 ft-L, contrast of 1.5-1.8, X-ray sensitivity of 0.03-0.05 R/min and resolution of 0.25-0.3 mm by penetrameter, and suggested wider applications in the filed of X-ray non-destructive inspection.抄録全体を表示PDF形式でダウンロード (1829K) -
鈴木 寿, 林 宏爾, 久保 裕1979 年 26 巻 5 号 p. 192-194
発行日: 1979/07/25
公開日: 2009/05/22
ジャーナル フリーThe transverse-rupture strength of TiC-Mo2C-Ni cermets free from large residual pores was studied at room temperature and at 1000°C as a function of their domain (grain) size of the binder phase.
It was found that the effect of the binder domain size of cermets on the strength was similar to that of WC-Co cemented carbides, that is, the strength decreased with increasing domain size at room temperature, whereas at 1000°C it increased. However, it was demonstrated that in the case of cermets, the effect was not so marked; the dependence of the size of fracture source on the binder domain size was rather slight. The fracture of cermets was not always initiated from the domain boundaries of the binder in contrast to the case of cemented carbide.抄録全体を表示PDF形式でダウンロード (229K)
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