シェル型鑄物の機械的性質について

抄録

  This study was carried out to ascertain the difference of mechanical properties between the castings made with shell moulds and the conventional sand moulds. The casting metals used were cast iron, copper alloy (85-5-5-5) and some aluminum alloys, and they were poured into shell moulds, green or dry sand moulds respectively under the same conditions. In the case of shell mould castings, the effects of back-up materials were examined.
  By measuring the cooling rate and observing the macro-structures, it was found that the melt poured into sand mould solidified more quickly and much finer grain structure was formed compared to that of shell moulds. In spite of the coarser macro-structure, the mechanical properties of certain shell mould castiugs were comparatively better than those of the sand mould castings. These experimental results seem to attribute to the fact that the cooling rate in the shell mould backed up with appropriate materials contributes to the directional solidification of alloys.