巻号一覧
19 巻, 5 号
選択された号の論文の5件中1～5を表示しています
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富田 耕平, 今林 守, 岩村 霽郎, 江刺 清夫1969 年 19 巻 5 号 p. 169-177
発行日: 1969/05/30
公開日: 2008/07/23
ジャーナル フリーThe present studies were carried out to establish the method for measuring gas content of pressure die castings and to find out the variation in gas content during the practical procees of die casting. Moreover, tests were made in detail on the effects of lubricant coated on dies and plunger speed on gas content of the test bar aluminum alloy die castings (ADC-12). In addition, variation in gas content at several positions of both of the test bar and practical castings was also studied.
The results obtained were as follows.
(1) The determination of gas content of pressure die castings was very accurate in liquid extraction mothod.
(2) The gas content of pressure die castings was much higher than that of gravity die castings. The source of a large amount of gases in pressure die castings was not due to the process of melting, degassing, and holding, but to casting process.
(3) The gas content of die castings remarkably increased with the increase of lubricant sprayed on dies.
(4) The gas content of die castings varied according to the composition of lubricant.
(5) The gas content of die castings linearly increased with the increase of plunger speed.
(6) The distribution of gas in die castings depended upon the individual positions; that is to say, its content increased along the length of the castings in the direction from gate side to overflow side.
(7) The gas content of die castings produced with no lubricant was about 20cc/100g on the side of overflow and about 8cc/100g on the side of gate.抄録全体を表示PDF形式でダウンロード (2571K) -
室町 繁雄, 佐藤 四郎, 大越 登1969 年 19 巻 5 号 p. 178-183
発行日: 1969/05/30
公開日: 2008/07/23
ジャーナル フリーCut-off turning tests were conducted on 12 sorts of wrought aluminum alloys now commonly used, and the effects of the rake angle of tool and the feed on the cutting resistance and chip thickness were examined. The rake angle was changed in the range of 1040°, and the feed was varied by three steps of 0.06, 0.10, and 0.16 mm/rev.
The main results obtained were as follows.
(1) Cutting resistance increased with the decrease in rake angle. The soft alloys, having Brinell hardness number (BHN) of below 40, showed much more increase in cutting resistance as compared with the hard alloys.
(2) Cutting resistance increased with the increase in feed. The rate of increase was approximatelyequal in both of soft and hard alloys.
(3) The effects of hardness of the material on the ratio of feed/chip thickness (or cutting ratio, r) are shown in Fig. 8. In hard alloys, having BHN of above 40, the cutting ratio showed relatively higher values of 0.50.6. However, in soft alloys, having BHN of below 40, showed a rapid decrease in the ratio, which was due to the formation of considerable thicker chips.
(4) Since chips of large thickness were produced in soft alloys, the width of shearing line was also large. Then, it seemed that they had high cutting resistance though the shearing resistance was low.抄録全体を表示PDF形式でダウンロード (688K) -
堀部 欽也1969 年 19 巻 5 号 p. 184-188
発行日: 1969/05/30
公開日: 2008/07/23
ジャーナル フリーIn the 2nd report, the author described the mechanism of pit formation on aluminum in artificial water (LSW 1) and presented a hypothesis concerning the pit formation on aluminum.
In this paper, there are reported studies on some methods for preventing or retarding pit formation on aluminum in LSW 1. No pits were formed on aluminum in LSW 1 during not very long period after the oxide film was removed from it (by electrolytic polishing). No pits were also formed after heating at around 500°C. Moreover, pits were hardly formed on Al-Mg alloy (Mg=2.57).抄録全体を表示PDF形式でダウンロード (1667K) -
Al-Mg-Si系合金の押出しに関する研究(第2報)高橋 恒夫, 小林 義一, 小島 陽1969 年 19 巻 5 号 p. 189-198
発行日: 1969/05/30
公開日: 2008/07/23
ジャーナル フリーAl-Mg-Si alloys of various chemical compositions were extruded at various temperatures, and extrudability and mechanical properties of extruded or annealed rods were examined.
The following results were obtained.
(1) Extrusion pressure was higher with the excess of Mg content over Mg2Si. When Cu and Fe contents increased, the extrusion pressure was higher.
(2) The mechanical properties of Al-Mg-Si alloys extruded at 440°C were indifferent to Mg and Si contents. However, when they were extruded at 520°C, hardness, 0.2% yield strength, and tensile strength were higher with the increase in Mg and Si contents. The mechanical properties of the extruded rods were more improved with the increase in Cu content, but the improvement was little for the rods extruded at 520°C with the increase in Fe content.
(3) The mechanical properties of Al-Mg-Si alloys extruded at 520°C were improved by annealing at 175°C for 3 hrs. with the increase in Mg and Si contents, but the improvement was not seen by annealing at 230°C for 1 hr. in spite of the increase in the both contents.
Cu improved mechanical properties of annealed rods, but Fe slightly improved them by annealing at 175°C for 3 hrs.抄録全体を表示PDF形式でダウンロード (1438K) -
財満 鎮雄, 高辻 雄三1969 年 19 巻 5 号 p. 199-206
発行日: 1969/05/30
公開日: 2008/07/23
ジャーナル フリーTurning tests were conducted on two sorts of JIS aluminum cast alloys, AC8A and AC8B, both corresponding to the so-called "Lo-Ex". The tests were for examining machinability of F-condition (as cast) and T6-condition (T6 heat-treated) of the materials from the viewpoints of cutting resistance, tool life, roughness of finished surface, chip formation, etc. The main results obtained were as follows.
In usual machining of aluminum alloys, the cutting resistance decreases with the increase in cutting speed and then, reaches a constant value regardless of the speed. However, in turning of "Lo-Ex", the resistance increased with the increase in speed; in particular, the tendency was greater in traversing force.
In turning of "Lo-Ex", the growth of built-up edge, which is likely to be observed at low cutting speed, gradually disappeared with the increase in cutting speed. Adhesion of the oxide-like deposit on the tool rake face, especially on the flank, grew up with further increase in cutting speed. The cutting resistance of AC8A was higher than that of AC8B, and the resistance of F-condition was higher than that of T6 condition in the both alloys.
The wear of tool was not negligible in turning of "Lo-Ex". The rating of machinability determined by the wear of tool showed that 8BF had the best machinability with the least tool wear, and the decreasing order of machinability (or increasing order of wear) was designated as follows.
8BF<8AF<8BT6<8AT6
Furthermore, no great troubles were seen in surface roughness, chip treatment, etc. for turning of "Lo-Ex".抄録全体を表示PDF形式でダウンロード (3393K)
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