| 摘要 |
PURPOSE:To produce a casting having substantial wear resistance with good dimensional accuracy by forming a surface layer consisting of a wear resistant metal or the like having a specific mesh to a specific thickness on the surface of the part requiring wear resistance of the casting. CONSTITUTION:Wear resistant metallic powder or the like having 150-325 mesh is tightly adhered to 1-3mm. thickness by means of a plastic film 4 onto a casting pattern 2 in the part of said pattern 2 requiring wear resistance on a plate for vacuum molding. A molding flask 5 for vacuum molding is further placed on the plate 1 and the vacuum molding is performed by a film 7, by which a cope and a drag 8 stuck with the hard powder 3 are obtd. The cope and drag 8 are mated to form a casting mold. When a molten metal is poured into the mold, the film 4 is burned away and the inside of the mold cavity is evacuated and therefore the molten metal infiltrates among the hard particles of the molding 3, thereby packing the gaps among the particles. The wear resistance of the surface requiring wear resistance of the casting is thus manufactured with good accuracy. |
