| 摘要 |
PURPOSE:To obtain a casting coated tightly with ceramic material and excellent in resistances to heat, corrosion and wear, by filling the surrounding of an investment mold with ceramic material and holding its surroundings by heat insulating material and pouring a molten metal into the mold under the reduced pressure by evacuation. CONSTITUTION:A pattern 2 of expandable styrol is housed in a molding frame 1, and its outside is surrounded by the heat-insulating material 3 of excellent permeability and low heat conductivity, and further the molding sand 4 free from bonding material, such as slica sand, is filled in the surroundings of said material 3. Next, ceramic material 5 is filled between the pattern 2 and the material 3. Then, an airtight cover 6 consisting of incombustible material is put on the top of frame 1, and a gate part of pattern 2 is covered by a combus tible airtight film 7. Next, a molten metal is poured from the film 7 part while evacuating air from a vent plate 8 having a vent hole 9, to obtain a casting coated with the ceramic material 5 by burning and vanishing the pattern 2.
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