中文摘要：

以硅粉为主要原料,采用燃烧合成法制备微米级Si_3N_4粉体,以中粒径d50和粒径分布宽度d90-d10作为粒度评价指标,采用激光粒度仪研究了悬浊液固含量、超声分散时间、分散剂含量及沉降时间对粒度测量的影响.结果表明,激光粒度仪可用于检测燃烧合成的Si_3N_4粉的粒度分布,悬浊液固含量、超声分散时间、分散剂含量及沉降时间对粒度测量结果影响显著.水为分散介质时,最佳固含量1.25 g/kg、最佳超声时间60 min、最佳分散剂用量3 g/kg的条件下,超声分散后0.5 h内进行粒度测量最可靠.

英文摘要：

Silicon nitride powder was prepared by combustion synthesis with silica fume.The effects of solid content,ultrasonic time,dispersant concentration and settling time on the particle size measurements were investigated by using median particle diameter d50 and particle diameter distribution width d90-d10 as evaluation indications.The results indicated that the laser particle size analyzer was applicable to measurement particle size of silicon nitride powder by combustion synthesis showing high reproducibility.The above four factors influenced significantly on the measurement results.When solid content was 1.25 g/kg,the needed ultrasonic time was 60 min,and dispersant content was 3 g/g,optimum dispersion results of Si_3N_4 by combustion synthesis can be achieved using water as the dispersing medium.In addition,the particle size measurement was the most reliable within 0.5 h after ultrasonic treatment.