Structural features of tensile deformation in electrodeposited metals

Conclusions

The characteristic feature of the structure of electrolytic copper and nickel is the presence in the grains of subgranular dislocation boundaries and twinning of growth origin. The subgranular dislocation boundaries are mostly found in the form of planar networks of dislocations having almost screw orientation. Other types of boundaries were also noticed: edge boundaries, dipole configurations, volumetric dislocation nodes, and ragged boundaries. The presence of thermal and stress fields causes disintegration of unstable subgranular dislocation boundaries of growth origin. The disintegration of the boundaries is related to significant restructuring of the dislocation structure and is clearly demonstrated by various methods of physical analysis.

The stability of the structure formed during electrocrystallization and its evolution under load depend upon the stacking fault energy, the method of deposition and the subsequent thermomechanical treatment. Absence of unstable subgranular dislocation boundaries of growth origin in the structure, or their stabilization, is a necessary condition for obtaining galvanic coatings with good working properties.