Study of High Temperature Sintering Process on Characteristics of Al_2O_3-ZrO_2-TiO_2 Ceramics Systems

摘要

In this study, the effect of sintering temperatures on the microstructure and mechanical properties of Al_2O_3-30 wt.% ZrO_2-5 wt.% TiO_2 composite has been investigated. The samples were obtained by uniaxial pressing (210 MPa) and green compact sintered in air at 1550, 1600 and 1650 ℃ for 3 h. The relative density, average grain size, Vickers hardness, flexural strength and microstructural features were examined to correlate densi-fication with grain growth and secondary phase formation at higher sintering temperature. The average grain size of the sintered composite tends to be larger and suppresses the densification at high temperature sintering process. A relative density of 98.6% of the composite was observed at 1550 ℃. At higher sintering temperature and TiO_2 addition, the formation of secondary phase of Al_2TiO_5, which has lower elastic modulus and consisted of larger grain size, reduces the flexural strength and Vickers hardness of the sintered bulk from 60.55 MPa to 34.40 MPa and 10.80 GPa to 5.73 GPa, respectively.