La ~ (3 +) / Ceo <sub> 2 </ Sub> Modification Of Cordierite Ceramics,

The present work aims to study the microstructure and properties of La³⁺ and CeO₂modified cordierite ceramics and porous cordierite ceramics. The cordierite ceramics wereprepared by sol-gel process and foaming process. The effects of rare earth on sintering andmechanical properties of cordierite ceramics have been systematically studied by means ofadvanced characterization techniques such as DTA and XRD. It was found that rare earthplayed a unique role in improving the properties of cordierite ceramics. This work is ofsignificance and importance to understand the mechanism of rare earth performing inceramics and to exploit new codierite materials.As a special sintering additive, La³⁺ results in significant effects in the process of phasetransformation toward alpha-cordierite. The addition of La3+ improves the properties of theceramics, decreasing the content of interphases (quartz, spinel, etc). The ceramics preparedby the sol-gel method were composed of alpha-cordierite and few interphases. The strengthand density of the ceramics increase with the increase of La³⁺ content. In addition,themicrostructure and properties of the ceramics strongly depend on the sintering temperatureand sintering time.The porous cordierite ceramics were prepared by the foaming process and the additionof CeO₂. It was found that the apparent porosity and average pore diameter presented thetrend of first decrease then increase with the increase of the CeO₂ content, while thecompression strength reversed to the above.