| 摘要 |
PURPOSE:To eliminate temp. gradient at inner and outer sides of a sintered body and to easily uniformize the sintering by dividing upper and lower punches also used for electrode into an outer circumferential part and an inner part and making heat conductivity of the inner punch larger than that of the outer circumferential punch at the time of heating the sintering powder with electric conduction under pressurizing. CONSTITUTION:Cavity 1 is formed with a graphite-made die 2 and each punch 3, 4 at upper and lower sides also used for the electrode, are set above and below the cavity 1 and connected with AC electric source 11 through electric conducting lines 9, 10, respectively. Each punch 3, 4 at upper and lower parts are constituted of the inner punch 5, 7 (Cu) at the inner part and the outer punch 6, 8 (graphite) at the outer circumferential part, respectively, and the heat conductivity of inner punch 5, 7 is made larger than that of outer punch 6, 8. In this constitution, the sintering powder 12 is packed in the cavity 1, and by conducting the electricity to the sintering powder 12 while pressurizing with each punch 3, 4, the sintering is executed. By this method, temps. at inner part and outer part of the sintering body are uniformized and the sintered body having uniform various characteristics of density, structure, hardness, strength, etc., without using complicated control system, is obtd. |
