The structure of interphase boundaries in an Al-Al3Ni directionally solidified eutectic alloy

Abstract
The crystallography and interfacial structure of a directionally solidified alloy consisting of aligned Al3Ni fibres in an Al matrix has been examined by transmission electron microscopy. In this particular alloy the faceted orthorhombic fibres and the f.c.c. matrix were aligned with 〈110〉m‖〈010〉f within experimental error. Three predominant interface facets which were all high-index fibre/high-index matrix planes could be identified. Detailed investigation revealed three sets of structural features in each interface. These features were interpreted as interphase boundary dislocations, geometrically required to relieve the misfit botwoen the two phases.