Although the solubility of Cu in Cr is negligible in the equilibrium state, Cu precipitates were discovered in extensively cold‐rolled Cr ribbons of Cu‐15 wt % Crinsitucomposite by means of analytical transmission electron microscopy (TEM) and high‐resolution electron microscopy (HREM). The precipitation sequence was found to be a Cu‐rich cluster ⇒ Cu GP zone ⇒ Cu equilibrium phase. ©1996 American Institute of Physics.