MESOTEXTURE IN ANNEALED NICKEL

Microtextures have been measured for compressed and annealed nickel which, since the data arose from contiguous grains, allowed the mesotexture - the texture between grains - to be collated. Nearly 2400 grain boundaries were included in the part of the study reported here. The microtexture and accompanying macrotexture showed a very weak compression fibre texture which became slightly more well defined after annealing. The mesotexture, assessed in terms of proximity to coincident site lattice (CSL) misorientations showed a bias towards low-SIGMA CSLs (SIGMA = 3 to 15) rather than high-SIGMA CSLs (SIGMA = 17 to 35). As annealing and grain growth proceeded, SIGMA = 3n boundaries (n = 1 to 3) became more prevalent in the mesotexture. A second nickel sample which had been annealed at a high temperature before compression had a mesotexture which was dominated by SIGMA = 3n boundaries. The differences between the two specimens was attributed to differences in impurity levels.