Analysis of creep pore formation in liquid-phase sintered alumina

Failure of ceramic materials used in high-temperature applications is initiated by the formation of creep pores. Thus, investigating the kinetics of creep pore formation, especially the evolution of their size distribution, is of key importance in obtaining an understanding of the failure mechanisms. This investigation is concerned with recent progress in the characterization of creep pores in liquid-phase sintered alumina by means of small-angle neutron scattering (SANS) techniques. It is shown that creep pores ranging from about 40 nm to >1 μm are present even after the small amount of creep deformation at the end of primary creep. For the first time a strong correlation between the size of glass pockets and the creep pores has been determined. The results give new insights into pore formation in liquid-phase sintered ceramics.