Formation mechanism of intragranular structure in nano-composites①
(1. Institute of Material Science and Engineering, Ocean University of China, Nanjing 210098, China;2. Key Laboratory for Engineering Ceramics of Shandong Province, Shandong University, Ji′nan 250061, China)
Abstract: The effect of sintering process and ZrO2contents on formation of intragranular ZrO2in Al2O3matrix was investigated withα-Al2O3micro-powders and ZrO2nano-powders as original materials. It is found that the second-phase particles coalesce with the growth of matrix grains during sintering. The process conditions that benefit the growth of matrix grains benefit the formation of intragrains. The formation procedure of intragrains could be described as follows. At
first, the particles are driven to agglomerate during densification of the matrix . Some particles move along with the migration of the matrix grain boundaries and tend to further gather, then become intergrains. Those gripped between the matrix grain boundaries become intragrains during the growth of matrix grains.
first, the particles are driven to agglomerate during densification of the matrix . Some particles move along with the migration of the matrix grain boundaries and tend to further gather, then become intergrains. Those gripped between the matrix grain boundaries become intragrains during the growth of matrix grains.
Key words: intragranular structure; grain growth; nanocomposites; formation mechanism