| 摘要 |
PROBLEM TO BE SOLVED: To extend the service life of a molten metal pouring sleeve whose ceramic layer is difficult to crack, by arranging a second ceramic layer on the surface of a first ceramic layer arranged on the inner wall surface of a cylindrical body and by that the expansion coefficients of the first ceramic layer and the base material of the cylindrical body are more approximated than those of the second ceramic layer and the bare material of the cylindrical body. SOLUTION: The bugle-like cylindrical body 90 is formed as the base material of the molten metal pouring sleeve S for casting mold. On the inner wall surface of the cylindrical body 90, the ceramics is thermally sprayed to form the first ceramic layer 91. Further, the ceramics having different property to the first ceramic layer 91 is thermally sprayed on the surface of the first ceramic layer 91 to form the second ceramic layer 92. Then, the thermal-expansion coefficient of the first ceramic layer 91 and that of the base material of the cylindrical body 90 are mutually nearer values than in the relation of the coefficient of the second ceramic layer 92 and that of the body 90. Since the base material of the cylindrical body 90 is an iron material, the thermal-expansion coefficient of the second ceramic layer 92 becomes larger than the thermal-expansion coefficient of the first ceramic layer 91.
|
