Dislocation Arrangements Resulting from the Diffusion of Zn into Cu: Etch-Pit Studies

Zinc was diffused for 100 h at 780°C into the (111) surface of thick copper single crystals from zinc vapor in equilibrium with 10 wt.% zinc copper. Dislocations were produced in the crystals and were revealed by etch-pitting isoconcentration (111) planes in the region of concentration change. The dislocation density was larger than 107 cm−2 near the exposed surface and decreased to about 5×105 cm−2 in the interior. Many of the dislocations were in the boundaries of subgrains which increased continuously in size from less than 20 to about 300 μ as the distance from the surface increased to 3.7 (Dt)1/2 (400 μ). The interior of many of the subgrains appeared to be free of dislocations.