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Microstructural evolution of cryomilled Ti/Al mixture during high-pressure torsion
Author(s)
Bahmanpour, Hamed
Sun, Yu
Hu, Tao
Zhang, Dalong
Langdon, Terence G.
Lavernia, Enrique J.
Date Issued
February 28, 2014
Type
Article
Abstract
To provide insight into the influence of the length scale on the kinetics of phase evolution during severe plastic deformation, we studied the microstructure evolution of cryomilled Al and Ti mixture, which is further subjected to high-pressure torsion (HPT). The cryomilled microstructure consisted of elemental Al and Ti, and the subsequent HPT deformation at ambient temperature led to the solid state formation of Al-rich intermetallics. X-ray diffraction peaks originating from TiAl2 and TiAl3 were observed after one revolution of HPT, suggesting a shear strain-assisted formation of the intermetallics. A high resolution transmission electron microscope confirmed the formation of TiAl2 following HPT for one revolution. Further HPT straining led to microstructure refinement and a mixing of the Ti and Al, as well as of any phases formed initially. The solid state formation of the intermetallics and the overall evolution of the microstructure are discussed based on the generation of a high density of lattice defects that evolve under the strain conditions present during HPT.
Citation
Journal of Materials Research, 29(4), 578-585, 2014