Tough and damage-tolerant monolithic zirconia ceramics with transformation-induced plasticity by grain-boundary segregation

Conventional ceria-stabilized tetragonal zirconia (Ce-TZP) with modest flexural strength has rarely been used as compared to yttria-stabilized zirconia, even though it excellent hydrothermal stability and high toughness. Ce-TZP-based composites were recently developed, being tough remarkably in combination transformation-induced plasticity. However, distinct from the widely applied composite approach improve of Ce-TZP, this study, a simpler easily tailorable method was proposed by doping aliovalent oxides that are able segregate at zirconia-grain boundaries. 0.2-1 mol% divalent different cation size (Mg2+, Ca2+, Ba2+ Sr2+) selected dope 10 zirconia. CaO MgO dopants enter Ce-TZP lattice showed grain-boundary segregation effect, thereby tailoring microstructure transformation behavior. At higher dopant concentration 1 or CaO, ceramics strong but brittle typical elastic linear fracture behavior, whereas low 0.1-0.2 0.2-0.4 doping, deformed in-elastically certain degree without changing Young’s modulus. transition between both behaviors, best toughness (>10 MPam1/2), biaxial (≥1200 MPa), reliability (Weibull modulus up 30) damage-tolerance obtained. In-situ testing revealed such deformable took place well before crack initiation large zone ∼100 µm ahead tip having formed failure.