Shrinkage of Large Isolated Pores during Hot Isostatic Pressing of Presintered Alumina Ceramics

Abstract

The shrinkage process of large pores during hot isostatic pressing (HIP) of presintered Al 2 O 3 and Al 2 O 3 ‐ZrO 2 ceramics has been investigated. Large pores were observed to collapse by grain‐boundary sliding, and then small pores resulting from the misfit of flowed grains disappeared, mainly by diffusion. Due to the high resistance to grain‐boundary sliding, the pores in the Al 2 O 3 ‐ZrO 2 ceramics were hard to eliminate.