In the development of tritium breeding ceramics, the lithium meta titanate (Li2TiO3) has attracted great interests for its distinguished properties as one of the most promising solid breeder materials 1. The release of tritium from ceramic breeder materials includes various transport steps such as diffusion in the grain, surface reactions on the grain surface, diffusion in the pores of breeder ceramic, etc. 2 If the mass transfer capacitance (K) is based on the diffusion in the grain, the diffusivity can be roughly evaluated using the equation 3.
where dp is the diameter of the crystal grain in breeder ceramic (m) and D is the diffusivity of tritium in the grain (m2/s). Therefore, the release of tritium behavior based on the transport phenomena in the grain such as diffusion in the crystal could be improved due to the smaller crystal grain size. Li2TiO3 chemical synthesis methods such as hydrothermal 4, 5 usually produce better homogenization of the particles at the molecular and atomic levels as well as nano-sized crystal grain.
Sintering is a very important step for ceramics fabrication. Sintering step is critical for preformed particulate body and achieves its final shape and attributes. So, the consciousness of the sintering mechanism and activation energy of nanocrystallites Li2TiO3 synthesized by hydrothermal method becomes useful. The concept of ? master sintering curve (MSC) developed by Su and Johnson 6 can be used to predict the densification behavior of a given powder and estimates its minimum sintering activation energy. Song and co-workers 7 constructed MSC over two consecutive densification stages. The recent approach has been successfully applied to micrometer-size of Li2TiO3 sintering system 1. On the other hand, Matsui and co-workers 8, 9 propose a useful analytical method which can be used to determine the sintering mechanism at the initial sintering stage by employing constant rates of heating (CRH) technique. This procedure has been successfully applied to the initial sintering stage of micrometer-scale Li2TiO3 powder in a previous study 10.
The present work, therefore, aims to establish sintering mechanism and activation energy for nanocrystallites Li2TiO3 synthesized by a hydrothermal method based on non-isothermal sintering and systematically analysis of the sintering of nanocrystallites Li2TiO3 ceramic.