Nanometer Stripe Microstructure of Supersaturated Solid Solution in Fe-Cu Alloy

Strengthening due to precipitation of Cu in the a-Fe matrix is an important phenomenon utilized in the design of HSLA steels. In the present work, the microstructure of supersaturated solid solution in Fe-1.18%Cu binary alloy was investigated by means of high resolution electron microscopy. The results indicated that the solid solution was heterogeneous, there were lots of Cu atom clusters, which consisted of diffractive stripe microstructure similar to twin crystal. Orientation deviation was observed between two （110）o planes in diffractive stripes, which results in light and shade contrast. Furthermore, formation mechanisms of the nanometre stripe microstructure were discussed in terms of the interaction of Cu and Fe atoms in the Fe-Cu binary alloys.