Abstract:

In order to improve the powders’ liquidity and explore the preparation processing of spherical powder, irregular shaped chromium powders were prepared for spherical powders using inductively coupled thermal plasma (ICTP) as a heating source. The factor of powders’ feeding rate which could influence the spheroidization efficiency and liquidity of spherical powder was studied. The micro morphology and flow-ability of the powders were characterized with the metallographic microscope and hall flow meters, respectively. The results showed that the vast majority of powders was spheroidized after plasma treatment. For the particle size of Cr powders between 200 and 300 mesh, the liquidity of spheroidized powder was enhanced and the spheroidization efficiency was also increased with the increased feeding rate. But when the feeding rate was 35g/min, its liquidity and spheroidizaton efficiency were about 56.18s/50g and 85.6% respectively which both reached the best effect.

Key words: Inductively coupled thermal plasma, Cr, Liquidity, Spheroidization efficiency

摘要：

采用感应耦合热等离子体作为高温热源，对形状不规则的铬粉末进行了球化处理，研究了送粉速率对球形粉末的流动性、球化率的影响，并采用金相显微镜和霍尔流速计对球形粉末的表观形貌和流动性进行了测定。研究结果表明：形状不规则的粉末经过等离子体处理后，绝大部分以上的粉末均变为球形或类球形。对于粒径在200～300目之间的铬粉，随着送粉速率的增加，球化后的粉末流动性逐渐增强，球化率增加；当送粉速率为35g•min^-1时，其流动性和球化率分别约为56.18s/50g和85.6%，两者均达到了最佳效果。

关键词: 感应耦合热等离子体, 铬, 流动性, 球化率