Some control mechanisms of spatial solidification in light alloys

Abstract

Two unconventional approaches of controlling the size and distribution of primary particles in aluminium and magnesium alloys are suggested. The first approach uses the ultrasonic cavitation treatment for multiplication of solidification sites for primary crystals by activating catalytic impurities that are present in the melt. The second way, on the contrary, involves elimination of active solidification nuclei by melt overheating with subsequent nucleation of primary particles at a higher undercooling. Both approaches result in refinement of primary crystals.

Structure and Mechanical Behaviour of Al-Sc Alloys

“…Combined alloying with Sc and Zr in the amount as low as 0.2 % of every element refines microstructure of casting and welding [14], improves workability and deformability of castings [7,12,15], leads to formation of a very uniform and fine cellular dislocation structure in wrought products, and impedes recrystallization.…”