Effect of Fe_2O_3 on the Densification Behaviour and Mechanical Properties of Zirconia-Toughened Alumina (ZTA) Composites Prepared by Two-Stage Sintering

摘要

The effect of Iron Oxide (Fe203) addition from 0 to 0.8 vol% on Zirconia Toughened Alumina (ZTA) with 10 vol% Yttria-Tetragonal Zirconia Polycrystals (Y-TZP) produced through conventional pressureless two-stage sintering (TSS) were investigated. The ZTA samples were sintered with first stage sintering temperature Ti ranging from 1400°Cand 1550°C with a heating rate of 20°C/min followed by second stage sintering temperature T2 of 1350°C and hold for 12 hours. The ZTA samples' were then evaluated on its' microstructure and mechanical properties such as grain size, bulk density, Vickers hardness, Young's modulus and fracture toughness. Compared to undoped ZTA composites, addition of Fe203 were beneficial in enhancing the composites' bulk density, Vickers hardness and restricting grain growth. Addition of 0.4 vol% Fe203 content and sintered at Ti of 1450°C was able to achieve 99% Theoretical Density (T.D.), Vickers hardness >18 GPa and Young's modulus >400 GPa.