Mechanical behaviour of yttria- and ferric oxide-doped zirconia at different temperatures

Abstract

The variation of strengh, deformability, fracture toughness and other characteristics of partially stabilized zirconia ceramics (Y–Fe–PSZ) doped with 3% yttrium and 3% ferric oxide over a temperature range from −140 to 1400°C were investigated. Fracture toughness ( K 1c ) values obtained by the methods such as SENB, SEPB, IS and IF were compared. Lower temperatures resulted in an increase in fracture toughness by approximately 29%. Using the Vickers indents as stress concentrators for the IS tests we derived the relationship between K 1c values and mean values of radial crack length described by a second-degree polynomial. The data for zirconia (Y–PSZ and Mg–PSZ) and silicon-nitride ceramics, as well as the fractographic data, were used to analyse the results. It was established that the addition of ferric oxide exerted a positive effect on the strengh and fracture toughness of zirconia ceramics.