Ultrahigh temperature in situ transmission electron microscopy based bicrystal coble creep in zirconia I

Abstract

This work demonstrates novel in situ transmission electron microscopy-based microscale single grain boundary Coble creep experiments used to grow nanowires through a solid-state process in cu- bic ZrO 2 between ≈1200 °C and ≈2100 °C. Experiments indicate Coble creep drives the for- mation of nanowires from asperity contacts during tensile displacement, which is confirmed by phase field simulations. The experiments also facilitate efficient measurement of grain boundary diffusivity and surface diffusivity. 10 mol% Sc 2 O 3 doped ZrO 2 is found to have a cation grain boundary diffusivity of D gb = ( 0 . 056 ±0 . 05 ) exp ( −380 , 0 0 0 ±41 , 0 0 0 RT ) m 2 s −1 , and surface diffusivity of D s = ( 0 . 10 ±0 . 27 ) exp ( −380 , 0 0 0 ±28 , 0 0 0 RT ) m 2 s −1 .