|About this Abstract
||MS&T21: Materials Science & Technology
||Controlled Synthesis, Processing, and Applications of Structural and Functional Nanomaterials
||Processing and Mechanical Properties of 3YSZ-Al<sub>2</sub>O<sub>3</sub> Core-Shell Nanocomposite Ceramics
||Kevin P. Anderson, Benjamin L Greenberg, James A Wollmershauser, Boris N Feigelson
|On-Site Speaker (Planned)
||Kevin P. Anderson
Through the mechanism of transformation toughening, zirconia with the tetragonal crystal structure is among the toughest ceramics (~5-10 MPa√m) while only being moderately hard (H<sub>v</sub> ~13 GPa). Conversely, alumina is one of the hardest oxides (H<sub>v</sub> ~18-20 GPa) with relatively poor toughness (~3 MPa√m). In an effort to enhance hardness while maintaining toughness, novel zirconia toughened alumina (ZTA) composites were synthesized by coating tetragonal phase 3 mol% yttria stabilized zirconia with alumina via particle atomic layer deposition (pALD) and subsequently densified using Environmentally Controlled – Pressure Assisted Sintering (EC-PAS). EC-PAS utilizes creation and preservation of pristine nanoparticle surfaces throughout the sintering process, applied pressure (<2 GPa), and low temperature (< 0.5 T<sub>m</sub>) to achieve densification with negligible grain growth. Fully dense, 3YSZ-Al<sub>2</sub>O<sub>3</sub> core-shell nanocomposites with hardnesses as high as 17 GPa and toughnesses as high as 10 MPa√m were created and characterized with XRD, SEM, and Vickers microindentation.