To reduce the sintering time without requiring a power source device of large current capacitance and to unnecessitate the coating of a releasing agent by filling a powdery material into a die contg. electrically conductive metallic boride, applying the pulse current thereto while it is nipped and pressurized and executing sintering by the operations of Joule heat and pressure.
The inside of a die 2 for electric sintering composed of a sintering die 3 and upper and lower punches 4a and 4b is filled with a powdery material 1 of an aluminum alloy or the like, which is arranged at the inside of a vacuum chamber 10. While the powdery material layer 14 is pressurized to about 150 Mpa via pressing boards 7a and 7b of pressurizing mechanisms 6a and 6b, the pulse current is applied from a pulse power source 12 for sintering via upper and lower punch electrodes 8a and 8b to generate Joule heat in the powdery material layer 14, which is sintered at a prescribed temp., e.g. of about 500°C, and after that, a sintered body 20 is taken out by using an auxiliary plunger or the like. The die 2 is formed by subjecting metallic boride powder such as TiB2 to hot pressing or the like, its electric resistance value is controlled to 10×10-7 to 10×10-1 ohm-cm, and its Vickers strength is controlled to 10 to 50 GPa.
TSUBOI SHIGERU
SHIOMI YASUAKI
SUGAI ATSUSHI
MURATA MASAHIRO
YOSHINO JUN
