The contribution of viscous flow to creep deformation of silicon nitride

For silicon nitride ceramics, in which a less refractory grain boundary amorphous film bonds more deformation-resistant Si3N4 grains, one of the possible creep mechanisms is the redistribution of this amorphous film. Although this mechanism has been confirmed by measuring the film thickness distribution before and after creep, it is not clear whether viscous flow occurs only in the initial stage of creep or throughout the creep process. In this …