The Effect of Sintering on the Properties of Ultrafine

摘要:

研究了一种化学气相沉积（CVD）制备超细铼粉的新方法，即以NH4ReO7为原料，通过将其分解为Re2O7后气相输运至还原区，经氢气还原生成超细铼粉。对不同还原温度下制备的超细铼粉样品，采用XRD、SEM、激光粒度分析进行表征，实验揭示了烧结作用对晶粒尺寸、形貌、表面状态及粒度等粉末性能的影响规律。结果表明，随还原温度升高，烧结作用增强，制备的超细铼粉晶粒尺寸增大，具有更好的球形度，表面趋于光洁，平均粒径增大。

Abstract:

A novel CVD method of preparing ultrafine rhenium powders was investigated in this paper. The Re2O7 gas obtained by decomposing NH4ReO7 was transported to the reduction chamber and then reduced by H2 to form rhenium powders. In order to evaluate the effects of sintering on properties of rhenium particles, such as crystal size, morphology, surface conditions and particle size, the samples of rhenium powders prepared at different reduction temperatures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and laser particle size analyzer. The experimental results show that the sintering effect among particles is enhanced with increasing of reduction temperature, resulting in larger crystal size, smoother surface and larger average particle size of the rhenium powder.