摘要
将醇盐水解制备的纳米氧化钛粉体（～13nm）在500～800℃下煅烧，用XRD研究氧化钛相变过程中粉体的热稳定性，发现在加入0．4wt％的金红石相作为晶种后；晶粒生长受到较好的控制，同时分别在30、57和200MPa下对纳米氧化钛样品进行热压烧结，用密度仪、压汞仪和SEM对烧结前后的样品进行表征后表明，700℃的热压烧结样品已开始致密化，200MPa、800℃热压烧结样品的相对密度为97．2％，此时3～15nm的小气孔仍难以消除，这些小气孔的存在是纳米氧化钛陶瓷在较高的压力下难以完全致密的主要原因．
Nanocrystalline titania powder was prepared by the hydrolysis of titanium butoxide. The grain sizes of the powder calcined at 500～800℃ were measured by XRD. It was found that the thermal stability of nanosized titania powder was improved by adding 0.4wt% rutile. Meanwhile,the powder compacts (green density was 68.3%) were sintered at 7500℃ and 800℃ under 30MPa,57MPa and 200MPa, respectively. The mcrostructural development was studied by Poresizer,Pycnometer and SEM. Because of the high pressure which increases intrinsic driving force for thediffosional transport of the pores, the densification process of hot-pressed samples commences at750℃. After the samples were sintered at 200MPa/80O℃, the relative density was about 97.2%.Furthermore, the interagglomerational pores with size of 3～15nm could be found in the samples,even if high pressure was used. Probably it is the main reason that the nanosized titania could notbe densified thoroughly at low temperature.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
1997年第6期785-790,共6页
Journal of Inorganic Materials
基金
国家攀登计划项目
关键词
氧化钛
晶种
热压烧结
陶瓷粉末烧结
纳米级
nano-titania, crystalline seed, thermal stability, hot-pressure sintering
