Intermetallic Al₃Sc: the temperature dependence of mechanical properties and deformation peculiarities

Abstract

The study of the mechanical behavior of intermetallic compound Al3Sc in a wide temperature range is of considerable interest due to the positive influence of the intermetallic Al₃Sc (which is formed with alloying by scandium of aluminum alloys) on the mechanical properties of these alloys. Intermetallic Al₃Sc was obtained by the technology of rapid solidification from the liquid state as a plate with thickness of 1,85 mm. X-ray analysis, optical microscopy, modern methods of indentation in the temperature range 615…196^оC were used to study of the structure and mechanical properties. It is shown that the temperature dependence of hardness of Al₃Sc is nonmonotonic. In the temperature range 450—550^оC it is shown a maximum, which can be viewed as the result of formation of sessile configurations of dislocation, which is typical for a number of intermetallic compounds. The termoactivation analysis of the plastic deformation with the determination of the activation energy of dislocation motion, the activation volume and strain hardening was performed. It is shown that the intermetallic compound Al₃Sc deformation mechanism is dislocation like in the crystals with a significant covalent component of interatomic bonding. Full text download