ON THE ORIGIN OF CUBE TEXTURE IN COPPER

A crystallographic etch in which 111 planes are exposed in copper has been used to determine the orientation of the neighbouring substructures surrounding cube oriented microbands in heavily cold rolled copper. These, after characterisation into orientation groups, were compared with the neighbourhoods of undeveloped cube oriented microbands in lightly annealed material in which almost all well developed recrystallised grains were of cube orientation. By inspection of the two sets of orientation neighbourhoods it is demonstrated that only cube microbands surrounded by material with a theta-degrees [111] orientation relationship provide cube nuclei. Thus the cube texture arises from competition between nuclei in a variety of orientation environments, the successful nuclei having environments into which they initially grow characterised by a theta-degrees [111] relationship. The process is best described as micro-growth selection, in which the local texture determines the viability and competitive advantage of nuclei, while the global deformation texture (i.e. that determined by traditional diffraction methods) is that which is consumed by those nuclei, with the possibility of further growth selection as recrystallisation proceeds.