Effect of organometallic-derived TZP nanoparticles on the mechanical properties of ZTA ceramics

The incorporation of t-ZrO 2 into α-Al 2 O 3 matrix is a widely established method for enhancing the mechanical properties of ceramic materials, i.e. , zicornia toughened alumina (ZTA). In this study, acetylacetonate zirconium and acetylacetonate yttrium were thoroughly mixed with α-Al 2 O 3 powder and then calcined to achieve a uniform dispersion of organometallic-derived tetragonal zirconia polycrystal (TZP) particles in nano-size onto α-Al 2 O 3 , forming a composite powder. The TZP particle size increased from 8 to 39 nm with increasing calcination temperature from 600 to 1000 °C. The TZP nanoparticles coated α-Al 2 O 3 powder was sintered by spark plasma sintering (SPS) to obtain ZTA ceramics. TZP is embedded in the face-centered cubic skeleton formed by α-Al 2 O 3 and restricts grain growth to each other. The highest hardness and toughness, i.e. , 18.81 GPa and 10.31 MPa m 1/2 , of the ZTA ceramics was achieved at 1400 °C by using the composite powder calcined at 600 °C.