| 摘要 |
PURPOSE:To produce sintered parts having excellent strength and mechanical properties by sintering the green compacts of metallic powder by heating, heating the surface layer parts of the resulted sintered bodies, passing said bodies through dies of a hot sizing device and making the surface layer parts compact. CONSTITUTION:Metallic powder is cold molded under pressure to form a green compact. The green compact is sintered by heating to obtain a sintered body. The body 1 is placed on the piston 6 of a product receiving cylinder 5, and is held in the coil of a high frequency induction heater 3 provided on the die 2 of a sizing device. High frequency electric current is conducted to the coil to heat the surface layer parts of the body 1 relatively deeply and quickly. The heated body 1 is forced downward with a punch 7 so as to be passed through the inside of the die 2 whereby the surface is plastically worked, the tooth profile is formed and the surface is sealed. Upon ending of the downward travel of the piston 6, a pusher 8 is operated to eject the product 9. |
