| 摘要 |
PURPOSE:To form a very small quantity of ruggedness on the surface of a material to be worked, by constituting a powder forming metallic mold with a die plate and a ram having an equal coefficient of thermal expansion, and a support plate having a coefficient of thermal expansion different from that of said die plate and ram. CONSTITUTION:The metallic mold for pressing and forming a powder material, etc. is constituted with the die plate 1 having a through-hole 1a, the ram 2 which is inserted into the through-hole 1a and whose tip face is on the same surface as the surface of the die plate 1, and a support plate 3 for supporting at least one of the die plate 1 and the rab 2, in the axial direction of the through-hole 1a. In this case, the coefficients of thermal expansion of the die plate 1 and the ram 2 are made equal, and the coefficient of thermal expansion of the support plate 3 is set to a different value which is larger or smaller than said coefficient of thermal expansion. In accordance with whether the coefficient of thermal expansion of the support plate is large or smaller the coefficient of thermal expansion of the ram, etc., the tip part of the ram 2 is recessed from the surface of the die plate 1 or projected, and a metallic old having the surface on which the ruggedness of about 200mum is formed can be manufactured. |
