| 摘要 |
PURPOSE:To produce a powder metallurgy compact having two layers of outer and inner sides under good productivity by making pre-green compact having a little smaller size than the complete size, sticking different kind powdery material through heating lost binder on the surface. CONSTITUTION:By using the powdery material with comparatively low cost such as Fe-C compound, the pre-green compact A having a little smaller size than the complete size is formed. On outer surface of the pre-green compact A, the powder of Fe-Cr-Ni-Mo-C series material, etc., is stuck by using the heating lost binder (for example, polyvinyl alcohol, etc.,) and dried. Successively, it is heated under pressurizing by using a hot press composing of an upper punch 1, lower punch 2, die 3, heat element 4 and center core 5. By this method, the compound powder having thick outer layer can be easily formed and the product cost is reduced.
|
