2004 Volume 45 Issue 8 Pages 2598-2601
The precipitation behavior and orientation relationships of icosahedral quasicrystalline phase (I-phase) and Laves phase precipitates in ferrite matrix have been investigated by transmission electron microscopy (TEM) in an Fe-10Cr-1.4W-4.5Co-0.3Si (at%) alloy. It is found that the precipitates of the alloy aged at 873 K are the I-phase but those of the alloy aged at 973 K are the Laves phase. Through a double aging experiment at both temperatures, it is shown that the transformation between the I-phase and the Laves phase occurs. Although a single orientation relationship is established between the I-phase and the ferrite matrix, three different types of the orientation relationships between the Laves phase and the ferrite matrix are obtained by the analysis of SAD patterns. The results can be explained by the coincidence between the five-fold symmetrical plane of the I-phase and the (1120) plane of the Laves phase on the phase transformation between them.
