射频等离子体方法制备球形化TC4 (Ti6Al4V)合金粉末

Spheroidization of TC4 (Ti6Al4V) Alloy Powders by Radio Frequency Plasma Processing

摘要:

本文通过射频等离子方法制备了高度球形化的TC4(Ti6Al4V)合金粉末。主要探究仪器送粉喷嘴高度、产生等离子体的功率、反应室的压力、原料粉体的粒径分布、送粉速率以及载气的气流速率等对于粉体球化率的影响，通过调节上述因素形成对比实验并得到不同实验条件下的球化粉体。通过SEM图像可观察粉体的形貌变化并计算比较粉体的球化率，通过XRD图可知球化前后粉体相结构不发生变化，观察球化粉末横截面可知粉末为实心球体且表面光滑，同时可发现球化后粉末流动性明显提高，松装密度大，粒径分布窄，适合3D打印等应用技术对于合金粉体的要求。实验中，调节送粉喷嘴高度为12.5cm，反应室压力为14.7psia，送粉速率为1.742g／min，产生等离子气的功率为27.2kW且控制原料粉体的平均粒径在38～63微米时可使得球化率达到99%，明显高于其他球化粉末制备方法。

Abstract:

Highly spherical powders were successfully produced with a radio frequency plasma system. Six influential parameters, namely position of the inlet nozzle, plasma plate power, chamber pressure, particle size distribution of raw materials, the feeding rate and the flow rate of the carrier gas were changed respectively and the spheroidization ratio was counted with the help of SEM images. The phase structure and morphology of the powders were investigated by XRD and SEM. Morphologies of the surface and cross section indicate that the spherical particles are dense with a relatively smooth surface. Fluidity and bulk density were both improved to be suitable for practical application. Spheroidization ratio as high as 99% has been reached when the position of the inlet nozzle is 12.5cm, the chamber pressure is 14.7psia, the powder feeding rate is 1.742g/min, the plasma plate power is 27.2kW and the average size of raw particles is around 38~63μm.