Enhanced heterogeneous nucleation of Al6(Fe,Mn) compound in Al alloys by interfacial segregation of Mn on TiB2 particles surface

Abstract

In this study, the composition templating theory for heterogeneous nucleation was applied to achieve TiB2 particles with Mn segregation on the surface, which supplied the initial composition for the heterogeneous nucleation. The interfacial segregation of added alloy element Mn and the other common impurities, such as Fe and Si, was investigated with scanning transmission electron microscopy (STEM). The modified TiB2 particles was applied in Al-2.0Mn-1.0Fe alloys to test its effects on grain refinement of Al6(Fe,Mn) compound. The interfaces between Al6(Fe,Mn) particles and the engulfed TiB2 particles were examined with TEM observation.