Microstructure, mechanical properties and corrosion resistance of AZ31/GNPs composites prepared by friction stir processing

Abstract

The graphene nano-platelets (GNPs) reinforced AZ31 alloy composites were fabricated by friction stir processing (FSP) with three multi-pass and high rotation speed. The AZ31/2.14 vol% GNPs and AZ31/6.43 vol% GNPs composites were designed. The fine microstructure and uniform dispersion of GNPs were observed in the AZ31/GNPs composites. The hardness and tensile properties were enhanced after three cumulative FSP passes. This was attributed to grain refinement and strengthening effects of GNPs. The corrosion resistance of the AZ31/GNPs composites was improved due grain refinement, distribution of β-Al12Mg17 phase and anti-corrosion effect of GNPs. The tensile properties and corrosion resistance of the AZ31/6.43 vol% GNPs composite increased with increasing the volume fraction of the GNPs.