超细钨粉的粒度表征

Characterization of particle size of ultrafine tungsten powder

对供给态和研磨态超细钨粉的颗粒粒度进行了表征。将供给态粉和研磨态粉由激光衍射法、FSSS法和BET法测量出颗粒粒度。结果表明 :利用激光衍射法和FSSS法所测量出来的供给态粉和研磨态粉的粒度结果是错误的 ,这是因为测量系统的缺陷和测量原理的不合适导致的。可以使用吸附等温线来获得表面粗糙度的分数维维数D和微孔的表面积St,且用D和St 来修正dBET的计算公式。使用修正公式得到的

The particle size measurement of as-supplied and lab-milled ultrafine tungsten powders were investigated. FSSS method, laser diffraction method and BET method were used to perform the particle size measurement. Results show that the mean particle size values obtained from the above mentioned methods for as-supplied and lab-milled powders were misleading because of the defects of the measurement system or unsuitability of measurement theory. The fractal dimension of surface roughness and external surface area of pores obtained from adsorption isotherms were used to modify d BET calculation formula. By the modified formula, the calculated particle size values of four powders were in good agreement with the SEM sizes.