抄録
The construction and the performance of an experimental vacuum-hot press for refractory hard metals is described. A cylindrical graphite die,up to 6 cm in diameter, is directly heated by passing an electric current supplied by a 50 kVA-transformer, the secondary voltage of which is controlled by a 25 kVA-induction regulator in the range 0∼10 V. The density, electrical resistivity, hot hardness, resistance against corrosion, oxidation and thermal shock as well as the high temperature modulus of rupture of the specimen produced in this apparatus at the optimum temperature of 1430° were measured. It is concluded that the properties of the specimen so produced are superior to those of the specimen produced by cold-pressing of powders and subsequent vacuum-sintering.
