Relationship between mechanical properties and microstructure of yttria stabilized zirconia ceramics densified by Spark Plasma Sintering

Yttria stabilized zirconia ceramics are well known in the field of thermal barrier coatings due to their high ability to thermally insulate hot metallic parts of turbo-engines. The present work is focused on the mechanical properties and the fracture behavior of such materials shaped by Spark Plasma Sintering.1 Two types of powders have been used: i) the first one is a commercial powder made of micrometric spheroidal agglomerates of nano-crystallites (Tosoh), and ii) the second one is a home-made Sol-Gel powder 2 consisting of dense agglomerates of micrometric non-spherical crystallites. Both powders were shaped by Spark Plasma Sintering. The microstructures and mechanical properties of the various samples were characterized for different porosity rates and composition. The adjustment of several SPS processing parameters such as the temperature and the applied pressure allowed to obtain ceramics with a porosity in the range from 0 to 50 % vol. with oriented microstructure. Please click Additional Files below to see the full abstract