Evolution of pores during sintering of advanced oxide ceramic materials

The goal of this bachelor’s thesis is to experimentally specify behaviour of pores in oxide ceramic materials (Al2O3, t-ZrO2, c-ZrO2), particularly to describe the transition from open to close porosity. Ceramics powders made by different producers and with different initial particle size (Al2O3 – AKP30, REYNOLDS, TAIMICRON; ZrO2 + 3 mol.% Y2O3 – TZ3Y, TZ3YSB; ZrO2 + 8 mol.% Y2O3 – TZ8Y, TZ8YSB) were used. Samples were pressed by cold isostatic pressing CIP at pressures of 100MPa and 300MPa, and pressureless sintered up to relative densities up to 88-96%. The obtained results show, that evolution is mainly affected by material, independently of size of initial particles neither by initial shaping pressure. Elimination of open pores occurs in cubic ZrO2 at 91-92 % of relative density, in tetragonal ZrO2 at 92-93 % of relative density and in Al2O3 at 94 % of relative density