Thermodynamic analysis and experimental verification of interface reactions of iron aluminide/tetragonal zirconia composite

Abstract

This paper described the thermodynamic analysis and experimental verification of interface reactions between iron aluminide intermetallic and tetragonal zirconia. Thermodynamic analysis confirmed that chemical reactions between Fe–Al intermetallic and ZrO₂ (3 mol.–%Y₂O₃ stabilised zirconia) mainly depended on the Al content in Fe–Al intermetallic. For ZrO₂(3Y)/Fe₃Al composite, the interface reactions to form Al₂O₃ and ZrAl₂ would take place when Al content was >40 at-% in Fe–Al intermetallic, while no interface reaction occurred when using Fe₃Al as toughening phase. ZrO₂(3Y)/Fe₃Al composite was synthesised by hot press sintering to further verify the thermodynamic analysis of interface reactions between iron aluminide intermetallic and tetragonal zirconia. The phase composition, morphology and interface structure of ZrO₂(3Y)/Fe₃Al were investigated by X-ray diffraction, SEM and TEM. The results show that Fe₃Al was thermodynamic stable in ZrO₂(3Y) matrix, which was in good agreement with thermodynamically analysis.

Keywords:

• Interface reaction
• Iron aluminide intermetallic
• Tetragonal zirconia
• Composites

Acknowledgements

This work is supported by the National Natural Science Foundation of China (grant no. 51172095) and the National Natural Science Foundation of China (grant no. 61102006).