RF induction plasma spheroidization of tungsten powders

Irregularly-shaped tungsten powders(average granular sizes of 5~12 μm) have been spheroidized by radio frequency(RF) induction plasma. The effects of feed rate, mode of material dispersion, particle size on spheroidization efficiency are investigated. Experimental results show that the spheroidization efficiency decreases rapidly when the feed rate increases to more than 95 g/min. Only 30% spheroidization efficiency is gained at the feed rate of 135.75 g/min. The spheroidization efficiency is also affected by the flow rate of carrier gas. When the flow rate of carrier gas is 0.12 m3/h, the dispersion effect is the best, and the spheroidization efficiency is almost 100%. The apparent density of tungsten powders increases a bit with the increase of spheroidization efficiency. And the partic