Dendritic solidification microstructure affecting mechanical and corrosion properties of a Zn4Al alloy

摘要

In the present article some important trends have been shown regarding the relationship between solidification variables, microstructure, mechanical and corrosion properties of Zn-4 wt%Al alloy castings. The aim of the present work is to investigate the influence of heat transfer solidification variables on the microstructure of Zn-4 wt%Al castings and to develop correlations with mechanical and corrosion properties. Experimental results include transient metal/mould heat transfer coefficient (h i ), secondary dendrite arm spacings (λ 2), corrosion potential (E Corr), corrosion rate (i Corr), ultimate tensile strength (σ u ) and yield strength (σ y ) as a function of solidification conditions imposed by the metal/mould system. It was found that a structural dendritic refinement provides both higher corrosion resistance and better mechanical properties for a hypoeutectic Zn4Al alloy.