Plastic deformation of Fe–Al polycrystals strengthened with Zr-containing Laves phases: I. Microstructure of undeformed materials

The microstructures of several Fe-rich Fe–Al–Zr alloys have been studied as a basis of investigating the mechanical behaviour, which is subject of Part II. The alloys with only low Zr contents show microstructures with a relatively soft matrix and a hard skeleton along the grain boundaries, the latter being residual eutectics containing the matrix phase and the Zr(Fe,Al)2 Laves phase. Scanning electron microscopy, orientation imaging microscopy as well as transmission electron microscopy and diffraction are used to study the grain sizes, the orientation relationships between the grains and the phases and the crystallography of the Laves phase. With higher Zr contents above about 10 at.%, the matrix is formed by the Zr(Fe,Al)2 Laves phase.