Microstructure and Mechanical Properties of Microwave Sintered ZrO2 Bioceramics with TiO2 Addition.

Hsien-Nan Kuo,Tung-Kuan Liu,Jyh-Horng Chou

doi:10.1155/2016/2458685

Abstract

The microwave sintered zirconia ceramics with 0, 1, 3, and 5 wt% TiO2 addition at a low sintering temperature of 1300°C and a short holding time of 1 hour were investigated. Effect of contents of TiO2 addition on microstructure and mechanical properties of microwave sintered zirconia bioceramics was reported. In the sintered samples, the main phase is monoclinic zirconia (m-ZrO2) phase and minor phase is tetragonal zirconia (t-ZrO2) phase. The grain sizes increased with increasing the TiO2 contents under the sintering temperature of 1300°C. Although the TiO2 phase was not detected in the XRD pattern, Ti and O elements were detected in the EDS analysis. The presence of TiO2 effectively improved grain growth of the ZrO2 ceramics. The Vickers hardness was in the range of 125 to 300 Hv and increased with the increase of TiO2 contents. Sintering temperature dependence on the Vickers hardness was also investigated from 1150°C to 1300°C, showing the increase of Vickers hardness with the increase of the sintering temperature as well as TiO2 addition.

Highlights

Zirconia (ZrO2) has become one of the most important ceramic materials since 1970s because of the discovery of transformation toughening mechanisms
The aim of this study is to investigate the effect of TiO2 content on the microstructure and mechanical properties of the microwave sintered ZrO2 with TiO2 addition at a low sintering temperature and a short holding time
The intensities of main monoclinic (m) phases with reflections in 2θ = 28∘ and 31∘ both slightly decreased with increasing TiO2 content, indicating TiO2 additions into pure ZrO2 still have an effect on the phase transformation

Summary

Introduction

Zirconia (ZrO2) has become one of the most important ceramic materials since 1970s because of the discovery of transformation toughening mechanisms. It is well known that the monoclinic phase existed and is stable at room temperature up to 1170∘C; the tetragonal phase is formed and is stable at temperatures above 1170∘C up to 2370∘C; and the cubic phase is stable above 2370∘C [3]. ZrO2 ceramic shows many special properties, such as high elastic modulus, high fracture toughness, high wear resistance, suitable ionic conductivity, chemical inertness, and high melting temperature [2, 4]. Because of such excellent physical and chemical properties, ZrO2 ceramic is attractive to be a biomaterial and is a popular alternative to alumina as dental bioceramic [5,6,7]

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Conclusion