Fabrication of the novel hybridized AZ31B Mg/CeO₂+ZrO₂ composites via multiple pass friction stir processing

The mixture of the rare-earth CeO₂ and ZrO₂ particulates was used for fabricating the hybridized AZ31BMg/(CeO₂+ZrO₂)_p composites by utilizing friction stir processing with a multiple-tool pass strategy. The structure, mechanical properties (tensile strength and hardness), tribological performances (wear properties) and corrosion behaviours of the hybrid composites were examined. The findings reveal the elimination of tunnel-like defects and clustering of the CeO₂+ZrO₂ particles in the composite after the multiple passes of the tool due to the successive mechanical stirring-assisted material flow. The rise in the tool passes reduced the mean grain sizes (7.91–3.02 μm), the particle sizes (5.47–2.28 μm), the average friction coefficient (0.45–0.18) and the specific wear rate (4.26 × 10⁻⁵–2.17 × 10⁻⁵ mm³/Nm) of the composite. The tensile strength (172–239 MPa), and the corrosion performance of the hybrid composite were also improved via the multiple tool pass strategy. Multiple tool pass is thus recommended for the fabrication of Mg-based hybrid composites.