摘要
采用无包封SHS -HIP工艺在 10 0MPa的高压氮气下 ,制备了致密度较高的AlN陶瓷 ( 88% ) .研究了添加剂氧化钇 (Y2 O3)对氮化铝陶瓷高压 ( 10 0MPa)燃烧合成致密化的影响 ,并分析了产物的微观组织 .DSC分析表明 ,Y2 O3添加剂在 14 0 0℃前保持稳定 ,不参与燃烧合成反应 .在燃烧反应的高温下Y2 O3与杂质A2 O3形成液相Al5Y3O1 2 ,实现液相烧结 .随Y2 O3含量的提高 ,液相烧结作用增强 ,使产物致密度提高 ,产物的抗弯强度及断裂韧性得到改善 ,另一方面使产物中残余Al的含量增加 ,产物的硬度下降 .产物AlN在燃烧合成的高温致密化过程中发生塑性变形 。
Relative compact AlN ceramic was fabricated by combustion of Al particles in super-high pressure nitrogen at 100 MPa, and a relative density of 88% was gained. The effect of additive Y 2O 3 on combustion synthesis and microstructure was researched. It was shown that additive Y 2O 3 remains stable and stays out of the combustion reaction at 1 400 ℃. Liquid sintering occurs when eutectic melt Al 5Y 3O 12 was formed from Al 2O 3 and Y 2O 3 at a high temperature. With the increasing of Y 2O 3 content in the reactant, porosity of product decreases, content of residual aluminum in product increases, and the bending strength and fracture toughness were improved. Many dislocations and a little twins in AlN phase of SHS product were found, which showed that AlN ceramic is plastic at high temperature of the combustion reaction and deformation is generated during the SHS-densification.
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
2002年第4期483-488,共6页
Journal of Harbin Institute of Technology
基金
国家 93 4专项基金资助项目
