鋳造工学
Online ISSN : 2185-5374
Print ISSN : 1342-0429
ISSN-L : 1342-0429
76 巻, 8 号
選択された号の論文の11件中1~11を表示しています
解説
研究論文
  • 頃安 貞利, 松田 政夫
    2004 年 76 巻 8 号 p. 679-686
    発行日: 2004/08/25
    公開日: 2011/02/01
    ジャーナル フリー
      Mica based high insulating coat and silica based normal insulating coat were prepared as a test coat. Plate aluminum alloy AC2A was cast using a cast iron mold coated with the test coat. The thermal conductivity of the coat was estimated from the relationship between the solidification time of the casting and the coat thickness. It was found that the thermal conductivity of the high insulating coat was about 30% of that of the normal insulating coat. The aluminum alloy plate was cast by the evaporative pattern casting process using the expanded polystyrene pattern coated with the test coat. When the silica sand was packed and the high insulating coat was coated with a pattern 1mm thick, the experimental value of the solidification time increased by about 20%, and the calculated value of the heat absorption by the mold reduced by about 20%, respectively, compared with when the normal insulating coat was coated. The effects of the high insulating coat on the solidification time and heat absorption by the mold increased with increasing coat thickness. When the steel shot was packed, these effects were more marked than when the silica sand was packed. With a practical coat thickness, the effects of the high insulating coat on the solidification time and heat absorption by the mold were smaller than the difference between the thermal conductivity of the high insulating coat and that of the normal insulating coat.
  • 頃安 貞利, 松田 政夫
    2004 年 76 巻 8 号 p. 687-694
    発行日: 2004/08/25
    公開日: 2011/02/01
    ジャーナル フリー
      The effects of the high insulating coat on the molten metal temperature during mold filling in evaporative pattern casting was investigated theoretically and experimentally. The numerical simulations for the temperature of molten metal filling into the cavity were obtained. It was found that the temperature drop at the melt surface for the high insulating coat was 60-65% of that for the normal insulating coat under the conditions of this work. An aluminum alloy plate was cast by evaporative pattern casting using an expanded polystyrene pattern coated by the high insulating coat. The temperature change of the melt surface to the melt flow direction was measured. Experimental results showing that temperature drop at the melt surface for the high insulating coat is smaller than that for the normal insulating coat were obtained, and agreed with calculations. Experimental data on temperature drop at the melt surface was smaller than the calculated values.
  • 眞鍋 豊士
    2004 年 76 巻 8 号 p. 695-699
    発行日: 2004/08/25
    公開日: 2011/02/01
    ジャーナル フリー
      When long pipe castings are cast by the evaporative pattern casting process, the collaspsibility of the mold inside the pipe occurs at a high probability. In this study, the compactability of molding sand inside the acrylic pattern placed in the vibration flask was measured. It was found that sufficiently high compactability in the pipe can be obtained. Two kinds of rotary vibrations in opposite directions were attempted at the 40 Hz for 30 s respectively under the conditions in this study, and the pipe casting was cast by the evaporative pattern casting process. Different thickness of the pipe casting caused by the rising of the core was observed even at sufficiently high compaction of the molding sand inside the pipe. In addition, casting defects due to the collaspsibility of the mold were observed by the retention of the thermal decomposition gas in the pipe. These casting defects were found to decrease by the coating of a low permeability coat upwards inside the pipe pattern.
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