The Effect of a Small Amount SiO₂ on Sintering Kinetics of Tetragonal Zirconia Nanopowders

In the present paper the sintering behavior of 3 mol% yttria-stabilized zirconia (3Y-TZP) with and without small amount (0.2 wt %) of SiO₂ additive was investigated. It has been studied the silica impact which was added in two ways (co-precipitation and mechanical mixing) on sintering kinetics of 3Y-TZP nanopowders at the initial sintering stage. It was found the silica additive leads to the changing in the predominant sintering mechanism at the initial sintering stage from volume (VD) to the grain boundary diffusion (GBD) in nanopowders obtained by co-precipitation. It was shown that the way of silica addition also significantly influence the sintering kinetics of 3Y-TZP. In case of nanopowders with silica additive obtained by mixing method, sintering process occurred due to the predominance of VD mechanism. It was found that the silica additive and the mechanical activation leads to the acceleration of the sintering process.