Flash‐Sintering+: Creep in Single Crystals of Cubic Zirconia

ABSTRACT The two principal mechanisms of creep are grain‐size dependent diffusional creep and dislocation creep, also called power‐law creep; the latter is viable in single crystals. Recent results have shown that flash can induce colossal concentrations of defects, leading to very high rates of atomistic diffusion. We were therefore curious if flash in single crystals placed under a compressive stress may enhance creep deformation. Thus, we have discovered, rather unexpectedly, that single crystals of cubic zirconia can deform at rates that are five to seven orders of magnitude faster than in conventional creep. In absolute terms ∼10 −9 to ∼10 −4 s −1 , at compressive stresses up to 40 MPa and at temperatures below 1200°C are achieved. We present a phenomenological formulation that relates the strain rate to the applied stress, with a power‐law exponent , an activation energy of , along with the function that expresses the influence of current density. About flash‐sintering+: flash experiments have moved significantly beyond sintering, propelled by high rates of diffusion with consequences in chemical reactions and creep in polycrystals and, as here, in single crystals, hence the annotation. More is in the wings.