巻号一覧
20 巻, 12 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
- >
- >|
-
アルミニウム合金におけるG.P.ゾーンの成長と復元(第1報)広瀬 洋一, 浅野 和彦, 平野 賢一1970 年 20 巻 12 号 p. 589-594
発行日: 1970/12/30
公開日: 2008/07/23
ジャーナル フリーThe mechanism of growth of G. P. zones in Al-20%Ag, Al-5%Ag, and Al-5%Ag-0.04%Sn alloys was examined by electric resistivity measurements and tensile tests.
The existence of two kinds of G. P. zones, ε and η, was confirmed in these alloys, and their ageing characteristics were satisfactorily explained in terms of the metastable miscibility gap given by Baur and Gerold. However, it was shown that the ε-η transition temperature in low silver concentration was much higher than the value expected from the metastable miscibility gap.
It was found that ε was made coarser according to the Ostwald ripening mechanism in later stages of ageing. The activation energy of growth of ε was determined to be 21.7kcal/mol.
Tin retarded the clustering during quenching and in the earliest stages of ageing, but accelerated the G. P. zone development in the next stages. After prolonged ageing, the effects of tin on the growth of ε were very little.
Effects of the quenched-in vacancies in later stages of ageing were also discussed.抄録全体を表示PDF形式でダウンロード (839K) -
アルミニウム合金におけるG.P.ゾーンの成長と復元(第2報)広瀬 洋一, 浅野 和彦, 平野 賢一1970 年 20 巻 12 号 p. 595-600
発行日: 1970/12/30
公開日: 2008/07/23
ジャーナル フリーThe mechanism of reversion in Al-20%Ag alloy aged at 70° or 130°C for different periods was investigated by measurements of electric resistivity and proof stress.
The resistivity of aged alloys was increased to the maximum, and then, decreased. While, the proof stress was only linearly decreased. The degree of reversion was satisfactorily explained in terms of the metastable miscibility gap given by Baur and Gerold.
The diffusion processes during the reversion was analyzed in reference to the metastable miscibility gap. It was shown that the reversion was due to the transition from η into ε zone, not due to the solution of G. P. zones. The activation energy of the diffusion of Ag during the reversion was determined to be 29.0kcal/mol by considering changes in the matrix concentration and the zone size depending upon the reversion temperature according to the metastable miscibility gap. The value was in remarkable agreement with the activation energy of diffusion of Ag in Al and Al-Ag alloy, or 29.0 and 28.9kcal/mol, respectively. Therefore, it was concluded that the rate controlling step in the reversion of Al-20%Ag alloy was the diffusion of Ag in Al-Ag solid solution.抄録全体を表示PDF形式でダウンロード (791K) -
アルミニウム合金の熱疲労に関する研究(第1報)井口 信洋, 磯部 俊夫, 渡辺 修一郎1970 年 20 巻 12 号 p. 601-610
発行日: 1970/12/30
公開日: 2008/07/23
ジャーナル フリーFailures due to thermal fatigue often occur in aluminum alloy pistons and cylinder heads of engines, especially in those of Diesel-engines owing to their high operating temperatures.
This paper reports a method for investigating the resistance of aluminum alloys to thermal fatigue and the phenomena in thermal fatigue tests of Al-Si base alloy castings.
The results obtained were summarized as follows:
(1) It was found that a high rate thermal cycling could be achieved with a thermal fatigue testing apparatus of high frequency induction heating type (not the Coffin type.)
(2) The number of cycles to failure was decreased with the increase in temperature amplitude, thermal stress amplitude, and plastic strain amplitude.
(3) Specimens were tested at an average temperature of 300°C; they were radially expanded in the section heated to the maximum temperature and necking appeared in the both ends of the expanded section. The deformation of specimens was related with the distribution and variation of hardness in the specimens. The hardness was decreased in the section heated to above 300°C; and was minium in the necked parts, wehre the fracture took place.抄録全体を表示PDF形式でダウンロード (1708K) -
高橋 恒夫, 神尾 彰彦, 小島 陽, チュン グエンアン1970 年 20 巻 12 号 p. 611-619
発行日: 1970/12/30
公開日: 2008/07/23
ジャーナル フリーThe transition of solid-liquid interface morphologies in unidirectionally solidified aluminum and aluminum-zinc alloys was investigated in relation to the freezing conditions and the redistribution of solute.
The morphology of solid-liquid interface in 99.997% aluminum changed from plane to depression, irregular cell, elongated cell, hexagonal cell, successively, with the decrease in the ratio of (temperature gradient, G)/(freezing rate, R). Each critical value of G/R for each transition of morphology was constant.
On the other hand, the critical values of G/R in aluminum-zinc alloys were larger than those in aluminum and depended upon the zinc contents. The morphologies of depression and irregular cell were formed in wide ranges of G/R and zinc concentration.
Solute segregation at depressions was found on the irregular cell interface in aluminum-0.50% zinc alloy solidified at G/R=11.6×103°C. sec/cm2, and its concentration of zinc was 0.91.4%. However, the zinc concentration at cell nodes was 2.02.4% on the hexagonal cell interface at G/R=4.1×103°C. sec/cm2.抄録全体を表示PDF形式でダウンロード (4228K) -
石鉢 豊明1970 年 20 巻 12 号 p. 620-627
発行日: 1970/12/30
公開日: 2008/07/23
ジャーナル フリーPDF形式でダウンロード (1197K)
- |<
- <
- 1
- >
- >|