A microstructural study of the direct bonding between (1120)-oriented Al2O3single crystals and Fe has been conducted by transmission electron microscopy and high-resolution electron microscopy. Two orientation relationships have been found between the ceramic and single grains of α-Fe: (1120)Al2O3//(110)Feand [0001]Al2O3//[112]Fe; (1120)Al2O3/(110)FEand [0001]Al2O3//[]110]Fe. Although the atomic structure of the interfaces has not been resolved yet, no evidence was found for any interfacial product between the two basic components; also, the presence of a minor quantity of Fe3O4(magnetite) in the form of fine precipitates homogeneously distributed within the Fe layer has no apparent influence on the crystallography of the interfaces.