Fabrication of Ni3Al thin foils by cold rolling and the mechanical properties

Thin foils of boron-free stoichiometric Ni3Al below 100 μm in thickness were fabricated by cold rolling of the sheets which were sectioned from directionally solidified ingots. Two types of deformation microstructure associated with fine slip traces and coarse, wavy shear bands were observed in the foils, depending on the initial rolling direction. In the case of near <112> rolling direction, the microstructure was rather homogeneous associated with a single {110} texture. In the case of near <001> rolling direction, the microstructure consisted of repeated double bands with differently oriented slip traces, having two different {110} textures. Both type of the cold-rolled foils had very high fracture strength, 1.7 - 1.9 GPa, as a result of heavy cold reduction. They showed bending ductility but no tensile ductility. No significant difference in the mechanical properties was observed between the two deformation microstructures. (author)