Sizing die for densifying surface of sintered body, production method using same, and product obtained therefrom

• Main Authors: Kawase, Kinya, Nakai, Takashi
• Format: Patent
• Language: English
• Published: 14.04.2020
• Subjects: AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKINGWITHOUT ESSENTIALLY REMOVING MATERIAL; CASTING; FORGE FURNACES; FORGING; HAMMERING; MAKING FORGED OR PRESSED METAL PRODUCTS, e.g. HORSE-SHOES,RIVETS, BOLTS OR WHEELS; MAKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES,OTHERWISE THAN BY ROLLING; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; POWDER METALLURGY; PRESSING METAL; PUNCHING METAL; RIVETING; TRANSPORTING; WORKING METALLIC POWDER

In a die for compressing and sizing a sintered body at straight portions, upper taper portions are provided on a die upper portion and a core rod upper portion, and the straight portions are provided at a die lower portion and a core rod lower portion. The die upper portion and the core rod upper portion have Young's moduli higher than the die lower portion and the core rod lower portion. The die upper portion and the core rod upper portion are made of materials having Young's moduli that are at least 50 GPa higher than that of the sintered body. The sintered body can be densified with a smaller ironing margin. Since the sintered body is ironed without being compressed, by the upper taper portions and the core rod upper portion having high Young's moduli, the die is prevented from breaking and being abraded due to ironing.