| 摘要 |
PURPOSE: To prevent the dislodgment of thermally spraying particles by molten metal and powder by thermally spraying a refractory material mixed with specific ratios of ZrO2 , Al2 O3 , SiO2 and TiO2 to a casting mold. CONSTITUTION: The refractory material consisting, by weight %, of 30 to 80 ZrO2 and the balance Al2 O3 , SiO2 or TiO2 or a mixture composed thereof is prepd. This refractory material is thermally sprayed on the surface of the metallic casting mold, which surface comes into contact with the molten metal. The ZrO2 has excellent heat resistance and thermal impact resistance. The Al2 O3 , SiO2 or TiO2 or the mixture composed thereof lowers the m.p. of the ZrO2 to <=2000 deg.C, has the heat resistance and does not degrade the durability of the thermally sprayed layer. The use of the Al2 O3 is recommended if the heat resistance and wear resistance are regarded important. The selection of the SiO2 is recommended if the low m.p. is regarded important and the selection of the TiO2 is recommended if the wear resistance is regarded important. Since the heating of the thermally spraying particles to the m.p. or above is possible, the bonding strength between the particles is intensified. |
