International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The investigation of influence of modified conditions on formation of complex materials based on tetragonal zirconia doped by d-elements of I group (Cu or Ag) was carried out, in particular the routes of synthesis and type of dopant. The kinetic parameters of separated stage of NPs formation (drying of hydrogel under MW irradiation, dehydration and crystallization of amorphous zirconia NPs) were estimated. It was shown, the dehydration of tetragonal zirconia hydrogel in conditions of MW irradiation occurs due in two stage. In contrast for Cu (or Ag) –modified hydrogels only one stage dehydration is observed. The dehydration and crystallization of unmodified and modified xerogel is studied by DSC method. It was shown that the kinetic parameters of dehydration depend as from nature of zirconium salts that were using for synthesis and type of dopant. For crystallization processes the some parameters (crystallization temperature, enthalpy) are saved features of dependence on route of synthesis for unmodified and modified systems. However, the behaviour of dependence of activation energy on route of synthesis is contrast for unmodified and modified systems.

Tetragonal crystals were formed at addition of yttrium oxide on concentration range from 2 to 4 mol. %. It was estimated the thermodynamic functions of these systems, in particular on values of free surface energy (Gs) and elastic energy (Ge) of crystals and their ability to respond on change of external conditions – temperature. It was shown for range of small sizes (size decreases at temperature growth) the concentration of dopants practically doesn’t influence on dynamic of change of Gs then as for range of particles size of 15-35 nm the concentration of dopant more significantly influence on the Gs. Analysis of dynamic of change of Gs and Ge values shows that for systems which have been formed at heat treatment before 700°C the change of these thermodynamics functions is bigger. In this time the dynamic of change of total Gs + Ge value for systems which was synthesized at different temperatures shows the influence on yttria concentration.