摘要
通过高能球磨将一定成分的W,La2O3粉研磨成纳米粉,在真空热压炉中将其烧结为块体的纳米晶电极材料。利用X射线衍射仪(XRD)、透射电镜(TEM)和扫描电镜(SEM)等手段分析晶粒的变化情况。结果表明,烧结的致密化主要在于纳米颗粒的重排,而不是传统的扩散;烧结过程中出现晶粒长大现象,但长大有限;机械研磨产生的内应变、某些杂质元素的存在等对烧结有促进作用。
Nanostructured-W- La2O3 composite powder was prepared by the high energy ball milling, or mechanical alloying (MA). Serially W-La2O3 electrode materials were fabricated by hot pressed sintering in vacuum,. In each case the nanostructural evolutions was observed as function of milling time and sintering temperature using SEM, XRD and TEM. The results show that the sintering densification depends on nanosize particle rearrangement rasther than conventional diffusion. The enhanced sinterability of MA W-La2O3 composite powder is attributed to their ultra-fine and homogeneously mixed state, high internal strain, as well as the sintering activation by impurity elements.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2003年第9期752-755,共4页
Rare Metal Materials and Engineering
基金
国家自然科学基金资助项目(50071043)
