Application of Al-Si semi-solid reaction for fabricating harmonic structured Al based alloy

Abstract

The present work deals with a novel approach of fabricating harmonic structure in Al alloy through the application of semi-solid reaction between Al and Si. The harmonic structured Al was prepared by powder metallurgy route, where the Al and Si powder were subjected to controlled mechanical milling followed by subsequent spark plasma sintering to make a compact. The sintered compact resulted in a network structure of hard interconnected silicon dispersed region combined with Al-Si solid solution phase, known as "shell", enclosing the soft phase of pure aluminum matrix known as "core". The harmonic structured Al compact demonstrated retention of both uniform and total elongation as compared to its heterogeneous bimodal structure counterpart, which is the typical feature of the harmonic structured material. The application of semi-solid reaction between Al and Si in fabricating harmonic structure proved to be effective in improving mechanical properties of Al alloy. Present work also discusses the deformation behavior of the sintered compacts, with respect to its strain hardening behavior.