巻号一覧
18 巻, 4 号
選択された号の論文の4件中1～4を表示しています
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窪田 治夫, 原 昭夫, 三宅 雅也1971 年 18 巻 4 号 p. 125-131
発行日: 1971/11/25
公開日: 2009/12/04
ジャーナル フリーThe mixing phenomena of WC and Co powders have not yet been made clear enough in spite of their importance in the Cemented Carbide industry. Therefore, in this paper the crushing of WC powders and the behaviour of their grain growth during sintering were examined using variousWC powders, i.e., coarse single crystal, coarse polycrystalline and medium single crystalline WC powders.
The obtained results were as follows;
(1) Coarse single crystal WC powders were crushed markedly by chipping in the early ball milling stage. There-after, average grain size of WC continued to decrease with the appearance of fine chipping powders. Therefore, the grain size distribution of the coarse single crystal WC powder grew wider with the increase of ball milling time.
(2) Polycrystalline WC powders were crushed in the same way as the above mentioned (single crystal) in the early ball milling stage. However, the grain boundary destruction seemed to be caused after having been WC crushed into the definite size.
(3) Single crystal WC powder of medium size were more difficult to be crushed with chipping than the coarse one.
(4) The grain growth of coarse single crystal WC during sintering is more rapid than polycrystalline one because the size distribution of the former was wider than that of the latter. Moreover the average grain size of WC in alloys formed medium single crystal WC powders in coarser than that from coarse one, because the former was less crushed than the latter.
(5) In sum, the crushbility of WC in ball milling and its grain growth in sintering did not only depend upon WC grain size, but also the manufacturing process.抄録全体を表示PDF形式でダウンロード (6752K) -
大森 慎一郎, 橋本 雍彦, 中村 定, 日高 謙介, 小平 良男1971 年 18 巻 4 号 p. 132-135
発行日: 1971/11/25
公開日: 2009/12/04
ジャーナル フリーThe binary nickel-boron system up to 33.3 at % B was studied by thermal analysis, microscopic observation, and by X-ray diffraction. The results are summarized as follows:
(1) Two kind of intermetallic compounds of Ni3B (m.p. 1, 166°C) and Ni2B (m.p. 1, 125°C) were confirmed.
(2) Eutectic reactions were observed between Ni (solid solution) and Ni3B, and between Ni3B and Ni2B. The eutectic point of each reaction was 18.0 at % B, 1, 093°C and 30.0 at % B, 1, 103°C respectively.
(3) The solubilities of boron into nickel were below 0.1 at % at 850°C, and below 0.2 at % at 1, 000°C.
From these results, the phase diagram of Ni-B system up to 33.3 at % B was compiled.抄録全体を表示PDF形式でダウンロード (2946K) -
ぶどう糖による還元析出機構(1)阿部 照衛, 原 善四郎1971 年 18 巻 4 号 p. 136-144
発行日: 1971/11/25
公開日: 2009/12/04
ジャーナル フリーIn case of the reduction of cupric sulphate aqueous solution by glucose, it was suggested from thermodynamical view point that at first some precipitates, presumably oxides, hydroxides or hydrated oxides, are formed from the solution upon heating, and subsequently the reduction of these intermediate precipitates should be operative.
The above suggestion was experimentally confirmed and an analysis of the chemical formulae of these precipitates was carried out by X-ray diffraction, chemical, thermal and infrared absorption spectroscopic analysis.抄録全体を表示PDF形式でダウンロード (3404K) -
焼結におよぼす仮焼の影響山口 修1971 年 18 巻 4 号 p. 145-149
発行日: 1971/11/25
公開日: 2009/12/04
ジャーナル フリーThis paper dealt with effects of a wet and a dry method in pulverization on sintering the non-stoichiometric PZT with an excess PbO, the powders containing after 1.0 PbO : 0.48 TiO2 : 0.52ZrO2 (molar ratio) powders were calcined at 600 and 800°C before the sintering.
Abnormal expansion was not recognized in specimens of calcined powders. The shrinkage of the specimen calcined at 800°C and treated by the wet method was smaller than that of the others. As a result, it was found that a mechano-chemical reaction between PZT powders and water takes place. For this reason, the sintered density of this specimen was lower up to 900°C.
The linear relation holded between crystal grain growth and sintering time, and the slope of which was 0.25-0.28.
The electro-mechanical coupling coefficients were 47-50% with regard to the sintered bodies pulverized by the dry method after heving been calcined at 800°C.抄録全体を表示PDF形式でダウンロード (2988K)
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