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 efect on the strengh and fracture toughness of zirconia ceramics.
© 1998 Elsevier Science Limited and Techna S.r.l.