Abstract: The chemically compatibility of iron aluminide with zirconia matrix was analyzed by thermodynamic theory.
The results show that the chemical interaction between iron aluminide intermetallic and zirconia matrix will not take place when Al<42at%,
and this result was certified by XRD,SEM and HREM. HREM image exhibits that the interface between Fe₃Al and 3Y-TZP is clean, and no reaction
phase exists at the interface. The atom arrangement beside interface between Fe₃Al and ZrO₂ is partly corresponding, existing at
semicoherent state. The mismatch degree δ of spacing between planes in crystal is 30%, and the dislocation induced by mismatch
exists at interface.

Key words: composite, chemical compatibility, thermodynamic calculation, interface