Measurement of Displacement Vector of Grains in Polycrystalline ZrO2 during High-temperature Deformation

Abstract

High-temperature tensile tests were repeatedly conducted for a TZP specimen at 1, 400°C in air at intervals of about 2% of the true plastic strain up to 17.4%. After each deformation, displacement vectors of the specified 760 grains were measured from their position vectors obtained by FE-SEM micrographs. In a short time period during plastic deformation, grains moved gradually turing to the tensile axis in a zigzag way. At an early stage of deformation, the length of displacement vector distributed in a wide range because of their initial configuration after sintering. Further plastic deformation, however, grains tended to have their own movements depending on the constraint of the surroundings. In a middle time period during plastic deformation, a group of grains moved to the same direction so that several domains were formed. However, the domains disappeared due to constraint by the surrounding matrix, and other domains were formed by re-combination of grains. In a long time period during plastic deformation, grains seemed to be moving along path lines of a non-compressive fluid subjected to uniaxial tensile loading.