摘要 |
An improvement in a powder metallurgic manufacturing process where metal powder is compressed and heated in a mould and heat is produced by conducting electric current through the mould and the metal powder as well as through at least one electrically resistive fireproof body in actual contact with the mould where heat produced in the body is transferred to the mould and the metal powder. The improvement comprises maintaining electric tension between 2 and 200 volts; the current efficiency per unit volume of the mould between 20 and 200 W/cm3; and the resistivity of the electrically resistive fireproof body between 0.03 and 100 ohm x cm. |