摘要
利用介质阻挡放电等离子体辅助球磨和普通球磨分别对Al_2O_3+C混合物料进行活化,研究等离子体辅助球磨活化后Al_2O_3+C合成AlN的碳热还原反应机制。结果表明,等离子体辅助球磨30h的Al_2O_3+C,在N2气氛中1 400℃下保温4h,Al_2O_3即可全部转化为AlN,Al_2O_3+C的碳热还原反应符合固-固反应机制。相对于球磨活化单一的Al_2O_3粉末,等离子体辅助球磨Al_2O_3+C混合粉末可以缩短10h的球磨活化时间,这主要是由于在等离子体与球磨的协同作用下,有利于Al_2O_3与C形成适于固-固反应的均匀互溶的精细复合结构,使得反应扩散通道增加,平均扩散路径缩短,这在动力学方面大大促进了Al_2O_3+C的碳热还原反应,并促使反应按照固-固机制进行。
Synthesis mechanism of AlN by Al_2O_3+C powders through carbothermic reduction reaction was investigated,in which the Al_2O_3+C powders was activated by plasma assisted ball milling(PM)or by conventional ball milling(CM).The results indicate that Al_2O_3+C powders activated by 30 hof plasma assisted ball milling can be converted to AlN totally through carbothermic reduction reaction when annealed at 1 400 ℃for4hin N2.It is solid state reaction mechanism for the carbothermic reduction reaction of Al_2O_3+C powders after plasma assisted ball milling.Compared to Al2O3 powders,the time for activation of Al_2O_3+C powders by plasma assisted ball milling is reduced 10 h mainly because a homogeneous miscible mixture was formed between Al_2O_3 and C phases.As a result of the cooperation of plasma and ball milling,the subsequent carbothermic reduction reaction of Al_2O_3+C in solid state is promoted kinetically due to the homogeneous composite structures which increase the reaction diffusion channels and shorten the average diffusion length significantly.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2016年第3期109-114,共6页
Journal of Functional Materials
基金
国家自然科学基金资助项目(51177008)
交通运输部应用基础研究资助项目(2015329815220)
福建省自然科学基金资助项目(2013J01202)
福建省科技计划资助项目(2016H6017)
福建省科技创新平台建设资助项目(2014H2001)
厦门南方海洋研究中心资助项目(14GZB66NF30)
