The formation of bulk nanograined Al3Ni intermetallics from elemental micro-powder mixtures of Al-25 mol.% Ni are studied after processing by high-pressure torsion (HPT) for various turns at 473 K and at 573 K. It is found that nanograined Al3Ni intermetallics with high angles of misorientation are produced at temperatures well below the melting temperature. The fraction of Al3Ni intermetallics increases by increasing the shear strain and increasing the HPT processing temperature. During HPT, both Ni and Al atoms diffuse significantly in each other with a diffusion coefficient well comparable to the atomic interdiffusion in the Al3Ni intermetallic at its melting temperature.
Research on Molecular Diffusion Coefficient of Gas-Oil System Under High Temperature and High Pressure