Role of in-situ nanocrystalline in solidification behaviors manipulation, microstructure refinement, and mechanical properties enhancement of Al-Cu4/Al-Mg1 alloys

Abstract

Innovative in-situ synthesis tactics of devising Al-Cu 4 /Al-Mg 1 alloy inoculated with Fe 80 -B 11 -Si 9 (at.%) metallic glasses were proposed to achieve comprehensive multiscale inoculation of the microstructure. The effects of inoculant on the solidification behaviors were studied, and calculated the mismatch between α-Al and Fe 2 B/Fe 3 Si according to the E2EM model. Formation of nano-Fe 2 B particles exerts low mismatch with α-Al was effective in stimulating heterogeneous nucleation. In the meanwhile, nano-Fe 3 Si particle and nano-Fe 2 B particle that is not trapped in α-Al dendrites hinder the movement of the S/L interface through adsorption, thus hindering the growth of α-Al dendrites. With inoculation, the grains of Al Cu 4 and Al Mg 1 got significantly refined. The manipulation of microstructure also includes weakening of element segregation and refinement of precipitation, which is ultimately accounted for the improvement of comprehensive mechanical properties. The various strengthening mechanisms of inoculated Al Cu 4 and Al Mg 1 alloy are explored, which offers an innovative idea for broadening the industrial utilization of metallic glass. • Fe 2 B phases stimulated the heterogeneous nucleation of α-Al dendrites and inhibited its growth. • The Al-Cu/Al-Mg eutectic reaction was promoted. • The addition of Fe-B-Si metallic glass significantly refined the size of precipitates. • The comprehensive mechanical properties of Al-Cu 4 /Al-Mg 1 were enhanced by Fe-B-Si metallic glass.