巻号一覧
22 巻, 4 号
選択された号の論文の9件中1～9を表示しています
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T.A. El-Bassyouni, A.R. El-Desouky1972 年 22 巻 4 号 p. 249-251
発行日: 1972/04/30
公開日: 2008/07/23
ジャーナル フリーAluminium-calcium alloys containing Ca from 0.394 to 1.970% were prepared. They were all given a special heat treatment program in order to precipitate compounds of Ca with the impurities of the aluminum used. Each alloy was given 60% reduction in height by cold pressing and then heated isothermally at four different temperatures, namely, 250, 300, 350 and 400°C.
The hardness was measured with time at each temperature. The values of the hardness at 300, 350 and 400°C behaved regularly, i. e., they decreased slowly at first, then followed by a sharp decrease and finally decreased slowly again. However, at 250°C, there was a return of some hardness in the region of the abrupt decrease in hardness.
These anomalies were attributed to internal oxidation of Ca. The presence of CaO was verified by its effect on hardness and recrystallized grain size.抄録全体を表示PDF形式でダウンロード (384K) -
尾堂 勲, 松崎 泰治, 新居 和久1972 年 22 巻 4 号 p. 252-258
発行日: 1972/04/30
公開日: 2008/07/23
ジャーナル フリーThe effects of precipitate particles on grain diameters and formability of 3003 alloy sheets were studied.
The dispersion degree of precipitate particles of the material was systematically changed by means of precipitation heat treatment after solution heat treatment at 630°C for 2 hrs.
Limiting drawing ratio, conilcal cup value, and Erichsen cupping value were measured to evaluate the formability after primary recrystallization.
Results obtained were summarized as follows:
(1) The smallest grain diameters and the highest formability were obtained by high temperature precipitation treatments at 560°C for 10 hrs. and 530°C for 36 hrs. The dispersion degree of particles was smallest under these conditions.
(2) Higher dispersion degree, lower formability, and larger grain diameters were obtained by precipitation treatments at lower temperatures than above.
(3) The material, which had been subjected to no precipitation treatments, was likely to have the same properties as those of the material precipitated at lower temperatures.
(4) Erichsen cupping value hardly depended upon the conditions of precipitation heat treatments.
(5) In conclusion, large particles, still remaining after the solution heat treatment, were sparsely dispersed, and the supersaturated Mn in matrix was precipitated in the form of a small amount of fine particles. The material having such structures brought about small grain diameters and high formability. In case of such structures, the material had least (100) planes parallel to the sheet plane.抄録全体を表示PDF形式でダウンロード (1112K) -
岡林 邦夫, 川本 信1972 年 22 巻 4 号 p. 259-268
発行日: 1972/04/30
公開日: 2008/07/23
ジャーナル フリーIn the previous papers, the authors described the wear and frictional properties of some typical aluminum alloy castings such as Lautal (AC2A-F), Lo-Ex (AC8A-T6), Y-alloy (AC5A-T6), and Al-Si alloys, and reported that these alloys had high wear resistance when combined with carbon steel and cast iron. In this paper, the wear of high strength wrought aluminum alloys, Al-5.3% Cu alloy and Al-4.1% Zn-1.5%Mg alloy, of which hardnesses had been varied by heat-treatments, was examined in the combination with carbon steel and cast iron.
The results obtained were summarized as follows:
(1) At a comparatively high sliding speed, seizure easily appeared on wrought aluminum alloys. The seizure appeared at a speed of about 1.5m/sec when rubbed with carbon steel, but it did not appear up to about 4m/sec when rubbed with cast iron, because graphite contained in cast iron acted as solid lubricant inhibiting intermetallic contact between sliding surfaces.
(2) At a low sliding speed of no appearance of seizure, dark layers containing iron or its oxide and/or aluminum oxide were formed on the sliding surface of aluminum alloys to prevent it from intermetallic contact. Therefore, the wear rates of both aluminum alloys and carbon steels or cast iron were very low.
(3) The heat treatment of wrough aluminum alloys was considered to have little effects on resistances to seizure and wear.
(4) Al-Zn-Mg alloy was superior to Al-Cu alloys in wear resistance under mild wear condition, but inferior in seizure resistance.
(5) The seizure appeared slightly more often in wrought aluminum alloys than in the aluminum alloy castings examined in the previous reports. The above facts would be explained by the phenomena that a greater amount of intermetallic compounds and hard pro-eutectic and/or eutectic silicon crystals were present in these alloy castings.
(6) In the combination of aluminum alloys with carbon steels and cast iron, the mechanical wear of steel and cast iron was restrained. The wear resistance of steel and cast iron was greatly improved by rubbing with aluminum alloys at a sliding speed of lower than 0.5m/sec for steels and at 12m/sec for cast iron.抄録全体を表示PDF形式でダウンロード (2049K) -
鈴木 寿, 菅野 幹宏, 浅見 重則1972 年 22 巻 4 号 p. 269-274
発行日: 1972/04/30
公開日: 2008/07/23
ジャーナル フリーReliable data on G. P. zone solvus temperatures (TGP) seem to have never been obtained so far in Al-Zn-Mg alloys. The authors determined the values of TGP in (α+T) two-phase Al-Zn-Mg alloys having various compositions such as 1.43.6 at%Zn and 1.43.5 at%Mg mainly by electric resistivity measurements. The values were also obtained by measuring hardness change during reversion treatments, and these values were compared with those of resistivity measurements.
The results obtained were summarized as follows:
The values of TGP obtained by means of electric resistivity measurements were in the temperature range of about 86153°C, which were lower by about 3035°C than Polmear's data (See Fig. 4). TGP became higher with the increase in ratio of Zn/Mg and (Zn+Mg) at.% in the specimens. The values obtained by hardness measurements were found to increase with the rise of pre-aging temperature and increase of its time, and they were always higher than those mentioned above. There results were considered to be mainly due to η'phase formed during reversion from coarser G. P. zone to η'phase. Therefore, TGP obtained by resistivity measurements would be considered to be most reliable in this alloy system as mentioned above.抄録全体を表示PDF形式でダウンロード (819K) -
財満 鎮雄, 稲葉 道次, 広野 雅道1972 年 22 巻 4 号 p. 275-280
発行日: 1972/04/30
公開日: 2008/07/23
ジャーナル フリーSevere tool wear is observed in machining of hypersilumin and it is desired to determine proper conditions for cutting in view of tool life. This paper describes that the effects of cutting conditions such as cutting speed and feeding on the tool wear are discussed in detail to determine the optimum conditions with respect to the tool wear.
The following two systems were selected for dry turning tests for constant depth of cut:
(1) Some combinations of cutting speed and feeding for a constant net time in turning full lenght of a cylindrical specimen.
(2) The cutting speed and feeding were voluntarily selected, regardless of the net time for turning.
The following results were obtained.
In the case of (1):
It was advantageous for less tool wear and lower cutting temperature to operate at lower cutting speed and more feeding.
In the case of (2):
The less feeding gave a little higher cutting speed and longer tool life, which would be economically profitable.抄録全体を表示PDF形式でダウンロード (944K) -
堀 茂徳, 上田 光, 古城 紀雄1972 年 22 巻 4 号 p. 281-285
発行日: 1972/04/30
公開日: 2008/07/23
ジャーナル フリーIn the previous paper regarding the drilling machinability of Al-Si alloys, it was indicated that ununiformly dispersed silicon particles behaved as chip breakers, which played a significant role in chip treatment in drilling.
From this point of view, the probability of failure of silicon particles by tension or rolling are examined in this paper.
Various Al-Si alloys of different silicon contents were annealed at 520°C for 20 hrs. to spheroidize the particles, and then, were deformed to their corresponding degrees of strain. The longitudinal section in the direction of deformation of each specimen was polished and observed by optical microscopy.
As the results of this metallographic examination, the probability of failure was obtained with respect to various strains and particle diameters. The following equation was empirically deduced for tensioned specimens. PT=Cεnd where PT: the probability of failure of silicon particles by tension, C and n: constants, d: the particle diameter n is about 0.6 for eutectic silicon particles and 1.0 for pro-eutectic ones.
It was found that the probability of failur in a rolled specimen was higher than that in a tensioned specimen.抄録全体を表示PDF形式でダウンロード (1047K) -
鈴木 寿, 菅野 幹宏, 福永 和義1972 年 22 巻 4 号 p. 286-294
発行日: 1972/04/30
公開日: 2008/07/23
ジャーナル フリーThe effects of addition of a small amount of Mg atoms on initial aging rate of Al-(3 or 5 at%) Zn alloys were investigated in order to clarify the mechanism that G. P. zone formation is remarkably suppressed by this addition. The specimens were composed of two sorts of alloy systems; Al-3 at%Zn-Mg and Al-5 at%Zn-Mg, in which Mg contents were systematically changed.
In these studies, special attention was paid to the compositions of specimens whether they were two-phase or three-phase alloys at each aging temperature. Since the aging behavior would be different between two-phase and three-phase alloys, the two-phase alloys should be required for the quantitative studies of the above mechanism.
The results obtained were as follows:
(1)The compositions of Mg limit(between two-phase and three-phase alloys)in each alloy system were determined as a function of temperature by means of X-ray analysis and resistivity and calorimetric measurements. The results revealed that all specimens, which showed suppression phenomena in previous investigations, were surely three-phase alloys at each aging temperature.
(2) It was confirmed that the aging curves of the two-phase specimens did not show any suppression in the initial aging rate in quite the same way as in Al-Zn binary alloys. Whereas, in three-phase specimens, the suppression was more marked with the increase of Mg content.
(3) The suppression phenomena observed in three-phase alloys could be explained by the slow rate of formation of the 2nd G. P. zone, which would have appeared during the aging probably corresponding to θ (Mg2Zn11) stable phase.
(4) As the results, the previous theories which explained the retardation of the initial aging rate in Al-Zn-Mg alloy system on the assumption of interaction between vacancy and Mg atom were proved to be erroneous.抄録全体を表示PDF形式でダウンロード (1422K) -
坂本 憲一1972 年 22 巻 4 号 p. 295-308
発行日: 1972/04/30
公開日: 2008/07/23
ジャーナル フリーPDF形式でダウンロード (1676K) -
大谷 文太郎1972 年 22 巻 4 号 p. i-ii
発行日: 1972/04/30
公開日: 2008/07/23
ジャーナル フリーPDF形式でダウンロード (253K)
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