Differential speed rolling of Ni3Al based intermetallic alloy – Effect of applied processing on structure and mechanical properties anisotropy

Abstract

Results of the first principles study on the effect of differential speed rolling (DSR) and a post-deformation annealing on a microstructure and microtexture evolution as well related mechanical properties anisotropy and formability of Ni3Al-based intermetallic alloy, have been shown in the present paper. Results of the EBSD structure analysis and mechanical properties evaluation indicate that the application of the proposed DSR process leads to a higher stored energy of deformation (and thus a higher strain hardening) than in the case of the conventional rolling process. Consequently, a subsequent post-deformation annealing results with a greater extend of the structure restoration processes than in the case of the normal cold rolling. The formability of the investigated intermetallic was evaluated by both a calculation of Lankford parameter (the r values) and Erichsen cupping tests. It is found that the susceptibility to deep drawing of the investigated Ni3Al intermetallic alloy is much lower than that of conventional deep drawn materials (e.g. aluminum alloys or low carbon steels). Nonetheless, the Ni3Al alloy exhibited a very low planar anisotropy and the yield strength anisotropy (and thus, a low tendency to strain localization upon drawing) independently on its structure state. This behavior should be mainly attributed to its simple phase composition (the lack of “a second phase” precipitation).