| 摘要 |
In this forging method, a heat sink (9), which has a plurality of pin fins (92) integrally formed on the upper surface of a base board (91), is formed. A back pressure applying pin (56) is slidably provided in a fin-forming hole (52) for forming each of the pin fins (92), said fin-forming hole being formed in a die for forging, and at the time of plastically deforming a forging material (W), back pressure is applied, by means of the back pressure applying pin, to a metal material as the forging material (W) flowing into the fin-forming hole (52). A recessed portion (76) is formed on the restraining tip surface of the back pressure applying pin (75), said restraining tip surface restraining the metal material, and a bonding protruding portion (93) is integrally formed at the tip of the pin fin (92) using the metal material applied to the inside of the recessed portion (76). |
