セラミックスサンドとその他鋳物砂の機械的強度からみた耐久性

抄録

  Recently, ceramics sand (spherical mullite beads) has become to be widely used as foundry sand because of its excellent reclamation performance. In this paper, the durability (rupture resistance) of ceramics sand, silica sand, chromite sand and zircon sand is studied by the S-6 method and the N. R. R. method. It is found that the rupture resistance is in a order of ceramics sand > zircon sand > chromite sand > silica sand. Particularly, the ceramics sand is hardly broken down even by heating and cooling it repeatedly, therefore little fine particles are formed in the process showing its good reclamation performance. However, silica sand and chromite sand are broken down without heating them. It is concluded that the breaking down in the later case is caused by not the thermal shock but the lower mechanical strength of the particles.