Effects of scandium additions on mechanical properties of cellular Al-based foams

By using titanium hydride as the blowing agent and Ca particles as the thickening agent, the cellular Al-0.24wt.%Sc and Al-0.41wt.%Sc foams with a porosity ranging from 48 to 86% were successfully fabricated via the melt-foaming method. The compressive behaviors and effects of minor Sc additions on the strengthening mechanism of the cellular Al–Sc alloy foams were investigated and discussed. The results show that minor Sc additions can dramatically improve the compressive strength of the cellular Al foams due to the grain refinement and pinning effect from the Al3Sc precipitates homogeneously distributed in the matrix after heat treatment, implying that the Sc addition coupled with proper heat treatment is an effective way to improve the mechanical performance for Al-based alloy foams.