MECHANISMS OF HIGH-TEMPERATURE CREEP OF FULLY STABILIZED ZIRCONIA SINGLE-CRYSTALS AS A FUNCTION OF THE YTTRIA CONTENT

High-temperature creep behavior of yttria fully stabilized zirconia si ngle crystals with various yttria contents in the interval 9.4 less th an or equal to x less than or equal to 21 mol% has been studied, The m echanical data have been collected as a function of both the temperatu re and the yttria concentration, The creep behavior has been explained in terms of a transition between a dislocation viscous glide and a di slocation climb controlled mechanism, making use of a generalized vers ion of a classical model for alloys proposed by Burton, The yttria con centration dependence of the creep rate has been connected with result s on cationic diffusivity, with a possible influence of impurities.