NEUTRON DIFFRACTION TOPOGRAPHIC OBSERVATION OF SUBSTRUCTURES IN Cu-BASED ALLOYS.

Neutron diffraction topography was applied to the direct observation of the substructure in a Bridgman-grown Cu-14%Ni single crystal with the growth direction nearly parallel to left bracket 111 right bracket . The observed substructure consists of bundles of rods extending throughout the crystal along the left bracket 001 right bracket direction, every rod having a square-shaped cross section of about 1 mm**2 and being arrayed regularly in both the (100) and (010) planes. This conclusion is discussed in comparison with our previous results for Cu-5%Ge.