Effects of ternary sintering aids and sintering parameters on properties of alumina ceramics based on orthogonal test method

The orthogonal test method was adopted to investigate the effects of ternary sintering aids and sintering temperature on properties of alumina ceramics. Based on results from statistical analysis, the important order of ternary sintering aids and sintering temperature on the properties of alumina ceramics was achieved. Results showed that the important order of parameters in the response of high bending strength was as follows: SiO2 content, MnO2 content, sintering temperature and MgO content. And the important order in the response of densification was as follows: sintering temperature, MnO2 content, SiO2 content and MgO content. By optimizing the parameters, when the MnO2 content was 2 wt%, SiO2 content was 0.5 wt%, MgO content was 0.3 wt% and the sintering temperature was 1550 °C, the highest bending strength of 458.1 MPa was obtained, which was attributed to the combined effect of fine grains, close contact among grains and high relative density. This investigate showed an available method about the effects of multiple processing parameters on properties of ceramics, which contributed to the preparation of materials with optimal properties.