Fractal Dimension Studies of Porous ZrO_2-Mg0 Fracture Surface

摘要

The porous ZrO_2-MgO composites were studied. The influence of the composition and sintering time on the grain size, porosity and pore sizes changes kinetics were studied. The fractal dimension of the fracture surface was determined by the method of vertical cross sections on SEM images. The kinetics of a change in the average size of micro- and macropores showed that with the sintering time increasing the system desire to form a unimodal pore structure due to volume shrinkage and pores coalescence. It was shown that changes of the fractal dimension reflect the stages of porous ZrO_2-MgO composite solid-phase sintering. The maximum value of the fractal dimension, 1.5, is reached at the transition from the first to the second stage of solid-phase sintering and is observed at the ratio of macro-and micropores 12.5, which indicates the formation of the most developed surface.