ZrO_2纳米级粉体烧结初期致密化过程

 纳米粉体在烧结初期有２个明显不同的烧结动力学特征阶段：第１阶段粒子间界面扩散引起的纳米粒子重排的扩散蠕变是烧结致密化的主要机理，动力学关系表现为线收缩率与时间呈直线关系，纳米粉体的高烧结性就源于这个阶段；第２阶段的烧结动力学关系则可以用传统的晶界扩散传质致密化理论来解释

MECHANISMS AND KINETICS OF THE INITIAL STAGE OF SINTERING OF ZrO 2 NANOMETER POWDER

The mechanisms and kinetics of the initial period of sintering of ZrO 2 nanometer powder studied by measuring the sintering shrinkage of powder compacts are divided into different stages. In the first stage, the sintering kinetic is written as Δ L/L 0∝t ,and the boundary diffusional creep,due to the boundary diffusion and the rearrangement of primary particles in compact, is the main factor affecting the sintering and sintering densification. The microstructure of the compact is characterized by the existence of a high coordination number of small pores. In the second stage, the sintering of compact is controlled by the grain boundary diffusion. An equation of the sintering kinetic of this stage can be expressed as Δ L/L 0∝t 1/3 .