Characterization of multiple twinned structural units in pulse-electrodeposited nickel

The investigation was performed on pulse-electrodeposited Nickel with submicrocrystalline microstructure containing slightly elongated grains having a <110> fibre texture in growth direction. Structural units in form of groups of elongated grains possessing a common <110>-zone axis in growth direction and CSL boundaries (in some cases twins) between them have been found in the microstructure by use of EBSD. Grain growth sets in above 325°C but the texture is conserved up to at least 600°C. This means that the arrangement of twins and other CSL boundaries stabilized the structural units; there is no orientation change (by further twinning) when grain growth occurs as seen in previous studies on Ni and Ni-Fe of different initial texture. The observed structural units were characterized in detail and the occurring grains and grain boundaries are described. (paper)