Fractal Dimension of the Fracture Surface of Porous ZrO_2-MgO Composite

摘要

Porous ZrO_2-MgO composites were studied. The influence of the composition and sintering time on the grain size, porosity, and kinetics of pore size changes was investigated. The fractal dimension and surface roughness of the fracture surface were determined by the method of vertical cross sections by SEM images. The kinetics of change in the average size of micro- and macropores with an increase in sintering time indicates the pursuit of the system to establish a unimodal pore structure owing to volume shrinkage and coalescence of pores, [t was shown that changes in the fractal dimension reflect the stages of solid-phase sintering of porous ZrO_2-MgO composite and occur only at the second stage of solid-phase sintering. The maximum fractal dimension, equal to 1.5, is reached at the transition from the first to the second stage of solid-phase sintering and is observed when the ratio of large and small pores is 12.5, which indicates the formation of the most developed surface.