Crystallographic orientations of Ni3Al-based aluminide

Abstract

Inverse pole figures have been plotted to determine preferred crystallographic orientations in a powder-compacted Ni3Al aluminide prealloyed with Fe, Ti and B. The main textural components, although weak, were noticeably altered by cold deformation, recrystallization and high-temperature deformation. Cold uniaxial compression generated a pronounced (110) orientation and the less common (112) orientation. The existence of the latter orientation was ascribed to the cubic --> tetragonal structural transformation (Ll(2) --> DO22) The beginning of recrystallization was characterized by a string of (113)+(112)+(111) orientations. However, after prolonged periods of annealing, the (113) orientation diminished, whereas the (111) and (112) orientations became stronger, perhaps due to preferred orientational growth. Deformation at high-temperature gave rise to strong (111) and (100)+(112) orientations. It was found that disordering and dynamic recrystallization simultaneously control high-temperature deformation.