Synergistic effects of ZrB2 reinforcement on mechanical strengthening and corrosion resistance in AA8011 aluminium composites

The AA8011 aluminium alloy is a lightweight structural and engineering alloy with relatively low mechanical strength, and localised corrosion weakens its performance in adverse environments. To overcome these limitations, ZrB-reinforced AA8011 aluminium matrix composites were fabricated using vacuum-assisted squeeze casting with varying reinforcement proportions (2 wt.%, 4 wt.%, and 6 wt.%) to exploit the synergistic effects of ceramic particle strengthening and microstructural modification. The inclusion of ZrB 2 helped refine the grains, disrupted the continuity of the Fe-rich intermetallic phases, and improved the interaction between the matrices and reinforcements, effectively transferring loads and strengthening the passive oxide layer. SEM observations reveal a finer and more uniform microstructure of the ZrB 2 -reinforced composites than the coarse dendritic microstructure of the base alloy. Although the elongation decreases from 26.84 ± 0.9% in the base alloy to 15.32 ± 0.6% in the 6 wt.% ZrB 2 composite, the material still retains reasonable ductility and exhibits significant increases in tensile (31.6%), compressive (37.14%), flexural (36.20%), and impact strengths (34.54%), as well as hardness (35.6%), all of which increase systematically with higher ZrB 2 content, and the corrosion rate is reduced to 37.72%. The results indicate that ZrB 2 reinforcement effectively addresses the inherent deficiencies of the AA8011 alloy, enabling the resulting composites to meet the stringent requirements of lightweight structural applications.