摘要
为拟制烧结后期的晶粒生长,采用二步烧结方法研究纳米BeO粉体的烧结。采用2个常规烧结实验确定每步烧结的温度范围之后,研究纳米BeO粉体的二步烧结工艺,通过扫描电子显微镜和图像分析软件研究烧结过程中微观组织结构的变化,采用激光导热仪测试材料的热导率,并分析纳米BeO粉体的二步烧结机制。研究结果表明:第1步的烧结温度(t1)范围为1 450℃≤t1≤1 500℃;第2步的烧结温度(t2)范围为1 300℃≤t2≤1 400℃;较合适的二步烧结工艺为:(1 450℃,1 min)+(1 400℃,25 h),该工艺下所得陶瓷的微观组织结构较均匀,致密度和热导率均较高,分别为96.6%和237 W/(m?K);在纳米BeO粉体的二步烧结过程中,晶界扩散和体扩散等利于致密化的机制起主要作用。
In order to control the grain growth during the final stage of sintering, two-step sintering method was employed to consolidate BeO nanoparticles. Experiments were conducted to determine the appropriate temperatures for each step, and then the two-step sintering process of BeO was studied. The two-step sintering regimes were also analyzed. The results show that temperature ranges for the first step sintering （t1） and the second step sintering （t2） are 1 450-1 500 ℃ and 1 300-1 400 ℃, respectively, the optimized two-step sintering process is （1 450 ℃, 1 min）＋（1 400 ℃, 25 h）, BeO ceramic with well-proportioned microstructure and comfortable relative density （96.6%） is achieved and its thermal conductivity is 237 W/（m×K）, and the sintering mechanism of nano-BeO is grain boundary diffusion and volume diffusion.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2014年第4期1043-1051,共9页
Journal of Central South University:Science and Technology
基金
国家青年自然科学基金资助项目(51202296)
中南大学博士后基金资助项目(2012年)
关键词
二步烧结
纳米BeO
烧结机理
热导率
two-step sintering
nano-BeO
sintering mechanism
thermal conductivity
