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

In the present paper authors investigated the effect of 2 wt % SiO₂ addition on the initial sintering stage of tetragonal zirconia nanopowder 3Y-TZP (ZrO₂-3 mol% Y₂O₃) which was manufactured by co-precipitation and mechanical mixing methods. It has been found that small amount SiO₂ has influenced on phase composition, crystallite size and agglomeration degree of zirconia nanopowders. The sintering behavior of 3Y-TZP with and without addition SiO₂ was investigated using the dilatometric data and analytical method for determining the sintering mechanism. The shrinkage behavior of all nanopowders was measured under constant rate of heating (CRH). The sintering mechanism on the initial sintering stage of 3Y-TZP changed from (VD) volume to (GBD) grain boundary diffusion by addition 2 wt% SiO₂ (3Y-TZP+2 wt% SiO₂) which have manufactured by co-precipitation method. The nanopowder 4PMM-3Y-TZP+2 wt% SiO₂ which has manufactured by mechanical mixing methods sintered according to (VD) volume diffusion mechanism.

In the present study authors examined the sintering behavior on the initial sintering stage of fine tetragonal zirconia nanopowders (containing 3 mol % Y2O3) with and without mechanical activation in a ball mill. The initial sintering behavior was examined by constant rate of heating method (CRH) at different heating rates. We defined a role of the particles surface mechanical activation and its influence on the sintering mechanisms during the sintering of yttrium-stabilized zirconia nanopowders. We found that even a small mechanical action causes change initial characteristics of nanopowdres which can accelerate sintering processes. Increases of milling time causes change of sintering mechanism from volume (VD) to the grain-boundary (GBD).