射频等离子体球化中钼粉颗粒加热过程的数值模拟

Numerical Simulation of Heating Process of Molybdenum Powder in Radio Frequency Plasma Spheroidization

对射频等离子体球化中钼粉颗粒的加热过程进行研究可以为优化等离子体制备球形钼粉的工艺过程提供参考。采用了数值模拟的方法研究了线圈电流频率、粉枪位置及送粉速率等参数对钼粉颗粒在射频等离子体中的运动轨迹及加热过程的影响效应。结果表明:线圈电流频率较低时,等离子体炬轴线附近的温度更高,钼粉颗粒在等离子体中运动时能够达到的温度也更高;改变粉枪位置仅对粒径较小颗粒的运动和加热有较大的影响;降低送粉速率可以提高颗粒从等离子体中获得的能量,从而在一定程度上提升钼粉的球化率。

Study on heating process of molybdenum particles in radio frequency plasma can provide theoretical guidelines for improving preparation process of plasma spheroidization. The effect of coil current frequency, position of injection probe tip and powder feeder rate on motion trajectories and heating process of molybdenum particles in plasma was studied by a numerical simulation method. The results show that molybdenum particles can be heated to higher temperature during the spheroidization process when coil current frequency is lower because of higher plasma temperature;Changing of injection probe tip position has great effect on motion and heating of smaller particles;Decreasing of powder feeder rate can increase the energy from plasma, thus improving the spheroidization effect.