感应等离子体球化处理难熔金属(W、Cr)粉末的研究

Study on Induction Plasma Spheroidization of Refractory Metal(W,Cr)Powders

采用感应等离子体球化技术对形状不规则的W粉、Cr粉进行球化处理,研究了喂粉速率对粉末球化效果的影响。采用SEM、XRD、激光粒度仪和霍尔流速计测试了等离子体球化处理前后粉末的形貌、物相、粒径分布和松装密度。研究结果表明,感应等离子体球化技术可制备出单相的球形W粉和Cr粉,粉末的松装密度和流动性显著提高;降低喂粉速率,W粉和Cr粉球化率均提高,最高球化率大于98%;原料粉末的分散度影响球化处理后球形粉末的粒径和粒度分布。

Induction plasma spheroidization process was applied to deal with irregularly shaped W and Cr powders,and the effect of powder-feed rate on powder spheroidization was investigated. The morphology, phase composition, particle size distribution and apparent density of the powders before and after sphe- roidization were characterized by scanning electron microscopy （SEM）,X-ray diffraction （XRD）,laser par- ticle size analyzer and Hall flow meter. The results show that the spherical W and Cr powders with single phase can be prepared by induction plasma spheroidization, and their apparent density and powder flow-ability are greatly improved. The spheroidization ratio of W and Cr powders increases with the decrease of powder-feed rate,and the maximum spheroidization ratio is higher than 98%. The particle size and particle size distribution of the sphericized powders are affected by the dispersion of the raw powders.