退火热处理对纳米钨粉体性能的影响

Influence of Annealing Heat Treatment on Properties of Nano-tungsten Powder

采用工业化生产技术制备纳米钨粉体,对样品进行不同温度热处理;采用SEM、XRD、EDS和全自动比表面和孔隙度分析仪对样品的形貌、物相、含量和比表面、孔结构进行表征。通过计算晶格变化率判断热处理后样品的晶格变化,并测量其粒径和孔容大小来解释晶粒的长大机理和孔结构的变化。结果表明:经热处理纳米钨粉体的晶格由收缩变为膨胀,且随热处理温度升高,比表面积和孔径均减小,粒径增大。当热处理温度达1200℃时,晶粒长大迅速,其长大机理根据晶界迁移解释。

Nano-W powder was produced by industrialized production technology, and the heat treatment of samples was carried out at different temperature. The morphology, phase, content and special surface area, and pore structure of the samples were characterized using SEM, XRD, EDS and automated surface area and pore size analyzer respectively. The lattice changes of the samples after heated treatment were judged by calculating the change rate of lattice, and the growth mechanism of grain and the change of pore structure were explained by measuring its grain size and pore volume. The results indicate that the lattices of nano-W powder after heat treatment have changed into expansion from contraction. With temperature increasing, the specific surface area and pore size decreases, and particle size increases. The grain growth is very rapid at 1200 ℃, and its growth mechanism is explained according to grain boundary migration.