无机材料学报2011，Vol.26Issue(6)：659-663,5.DOI:10.3724/SP.J.1077.2011.00659
Li2O对SPS烧结AlN陶瓷致密化、显微结构和导热性的影响
Effects of Li2O on Densification, Microstructure and Thermal Property of Spark Plasma Sintered A1N Ceramics
摘要
Abstract
A newly developed rapid densify technique, spark plasma sintering (SPS), is used to prepare full-densified aluminum nitride (A1N) ceramics which are poorly sinterable. Some sintering aids are also used to promote the A1N ceramics' densification and improve its thermal conductivity. In this work, effects of sintering aid Li2O on densifica-tion, microstructure and thermal property of SPS sintered A1N ceramics were investigated. Results suggest that the initial sintering temperature of A1N samples reduce from 1550℃ to lower than 1200℃ with 1.0wt% Li2O and 1.5wt% Sm2O3(or Y2O3) adding as sintering aids . With Li2O addition, A1N compacts can be fully densified at 1650 ℃. The microstructure of A1N compacts indicates that Li2O is beneficial to generate aluminate liquid phase with better wet-tability and promote the densification of A1N ceramics, but it is unable to obtain higher relative density of A1N compacts because the escapement of gas phase though out liquid phase is very difficult in a rapid sintering process. Meanwhile, Li2O addition affects the growth of A1N grains, and the better wettability of aluminate with A1N grain induces the homogeneous distribution of grain boundary phase. The deterioration of thermal conductivity of A1N ceramics is caused by the fact that the scattering of phonon is enhanced by small grain size and the secondary phase spreading adequately along the A1N grain boundaries. The thermal conductivity of AIN samples with 1.0wt% Li2O and 1.5wt%Sm2O3 as sintering aids is lower than that of sample only with Sm2O3 as sintering aids.关键词
烧结助剂/AlN陶瓷/SPS烧结/显微结构Key words
sintering aids/ aluminum nitride ceramic/ spark plasma sintering/ microstructure分类
化学化工引用本文复制引用
李美娟,沈强,罗国强,张联盟..Li2O对SPS烧结AlN陶瓷致密化、显微结构和导热性的影响[J].无机材料学报,2011,26(6):659-663,5.基金项目
国家自然科学基金(50972111) （50972111）
武汉理工大学博士科研启动基金(471-38650199) （471-38650199）
