Microstructure and Corrosion Behaviour of Solid-State Additive Manufacturing of AA6063 Al Alloy Composite

The present work describes the development of Al-alloy metal matrix composites (MMC) through the addition of ZrO ₂ to AA6063 alloy by friction stir rod additive manufacturing (FSRAM). It presents the comparative study of microstructure, tensile properties, microhardness, phases evolution, and corrosion behaviour. Grain refinement in both FSRAM-fabricated AA6063 alloy and AA6063/ZrO ₂ MMC is attributed to dynamic recrystallization induced by severe plastic deformation and due to the pinning effect of ZrO ₂ addition. SEM + EDX colour mapping shows that uniform distribution of their reinforcement particles without any accumulation will help in improving mechanical properties. FSRAM-fabricated AA6063/ZrO ₂ MMC exhibits the highest strength, followed by the FSRAM-fabricated AA6063 alloy, with the AA6063 alloy rod showing the lowest values. This superior performance is attributed to grain boundary and dispersion strengthening mechanisms, and the uniform distribution of reinforcement particles. FSRAM-fabricated AA6063/ZrO ₂ MMC demonstrates highest corrosion resistance, surpassing both FSRAM-fabricated AA6063 alloy and AA6063 rod. This enhanced resistance is due to forming a protective oxide layer, primarily ZrO ₂ , which acts as a barrier, preventing direct exposure of the alloy surface to corrosive environments. High strength and exceptional corrosion resistance of the AA6063/ZrO ₂ MMC make it a promising material for applications in the automotive, aerospace, chemical, and shipbuilding industries.