1995 年 35 巻 6 号 p. 764-770
The Plasma-Rotating-Electrode-Process (PREP) is based on the pulverization by rotation of meta bars in contact with a Ar/N2 plasma arc. Due to the high centrifugal forces of the rapidly rotating bars, high nitrogen steel powders are produced with diameters in the range of 0.02 to 0.5 mm. The low diameters and the high centrifugal forces, as well as the high particle velocities, cause the steel droplets to cool down rapidly in the reactor chamber. Mathematical calculations show that cooling rates of up to 105 K/s are attained. It is demonstrated that the cooling rate of all powder particles and the structures produced can be predicted.
