| 摘要 |
PROBLEM TO BE SOLVED: To enhance the concealing power of a core by a pressure resistant coating layer. SOLUTION: The surface of the sand core 7 is coated with a three-layered structure consisting of a primer coating agent containing TiO2 applied on the lowermost layer, a ceramic coating agent essentially consisting of SiO2 and MgO applied as a second layer and a flaky graphite coating agent applied as a third layer.
|
