Author(s)

Md. Abdul Gafur¹, Md. Al-Amin^1,2, Md. Saifur Rahman Sarker³, Md. Zahangir Alam²

¹Pilot Plant & Process Development Centre, Bangladesh Council of Scientific and Industrial Research, Dhaka, Bangladesh.
²Department of Applied Chemistry and Chemical Engineering, Dhaka University, Dhaka, Bangladesh.
³Kurigram Govt. College, Kurigram, Rangpur, Bangladesh.

Zirconia toughened alumina (ZTA) ceramics are very promising materials for structural and biomedical applications due to their high hardness, fracture toughness, strength, corrosion and abrasion resistance and excellent biocompatibility. The effect of unstabilized ZrO₂ on the density, fracture toughness, microhardness, flexural strength and microstructure of some Zirconia-toughened alumina (ZTA) samples was investigated in this work. The volume percentage of unstabilized ZrO₂ was varied from 0% - 20% whereas sintering time and sintering temperature were kept constant at 2 hours and 1580°C. The samples were fabricated from nanometer-sized (α-Al₂O₃: 150 nm, monoclinic ZrO₂: 30 - 60 nm) powder raw materials by the conventional mechanical mixing process. Using a small amount of sintering aid (0.2 wt% MgO) almost 99.2% of theoretical density, 8.54 MPam^? fracture toughness, 17.35 GPa Vickers microhardness and 495.67 MPa flexural strength were found. It was observed that the maximum flexural strength and fracture toughness was obtained for 10 vol% monoclinic ZrO₂ but maximum Vickers microhardness was achieved for 5 vol% ZrO₂ although the maximum density was found for 20 vol% ZrO₂. It is assumed that this was happened due to addition of denser component, phase transformation of monoclinic ZrO₂ and the changes of grain size of α-Al₂O₃ and ZrO₂.

Zirconia Toughened Alumina (ZTA), Mechanical Properties, Toughening, XRD, SEM, Grain Size

Gafur, M. , Al-Amin, M. , Sarker, M. and Alam, M. (2021) Structural and Mechanical Properties of Alumina-Zirconia (ZTA) Composites with Unstabilized Zirconia Modulation. Materials Sciences and Applications, 12, 542-560. doi: 10.4236/msa.2021.1211036.