冷凍鋳型の特性

抄録

  A study on the characteristics of the frozen mold was introduced to clarify the characteristics of sand bond and to obtain more information concerning the strength of the frozen mold. Scanning electron microscope observation and compressed destructive test were carried out on 50mmφ×50mm sand test pieces which were soaked in liquid nitrogen. In the frozen mold, sand bonds to the frozen moisture coated on the sand surface. The sand bond is firm just like the CO₂ process mold. This was indicated by scanning electron microscopy of the bond fracture using Wood's metal replica. The compressed strength of frozen mold is very high, but the strength changes according to the moisture content in the mold and the time soaked in liquid nitrogen. It is possible to make a sound coating by the frozen molding process. Moreover, it is believed that the frozen molding process excels in molding operation, preventing environmental pollution and cutting cost in the foundry shop.