Nanometer sliding of [001] symmetric tilt boundaries in copper with boundary precipitates

The inherent capability for [001] symmetric tilt boundaries of Cu to slide has been examined below 573 K using an electron microscope technique. The technique utilizes the sliding-induced rotation of moiré fringes on boundary b.c.c. Fe-Co particles in aged Cu-Fe-Co bicrystals and is capable of detecting sliding of not more than 1 nm. The activation energy for sliding against misorientation angle diagram displays several cusps and this diagram is similar to the boundary energy against misorientation angle diagram in Cu. A more disordered boundary has a lower viscosity.