Formation of Supersaturated Solid Solutions in Al Alloys with Transition Metals Upon Shear under Pressure

Metallographic, X-ray diffraction and electron microscopy were used to study the phase compositions and structure of rapidly solidified the Al- alloys transition metals (Zr, Fe, Cr) subjected to severe plastic deformation (SPD) by torsion under a high quasi-hydrostatic pressure. It was established that upon SPD a number and a size of aluminides decrease with increasing a degree of deformation. For example, the maximum effect of deformation - induced dissolution of the particles are observed in the case where they have a dendritic structure and are about one μm in size. Upon SPD the supersaturation of α-phase increases by a factor of 2.5. (for rapidly solidified Al-Cr and Al-Cr-Zr alloys) and by a factor of 10 (for rapidly solidified Al-Fe alloy). After SPD all alloys have submicrocrystalline (SMK) Al-based matrix with grain size of 100-200 nm and high hardness of 2 GPa. The thermal stability of SMK deformed materials and some specific features of post deformation phenomena as an aging and a recrystallization were investigated.