<p>5083Al/Al₂O₃ interpenetrating phase composites (IPCs) were fabricated via pressureless infiltration. Their tribological and corrosion properties in a simulated seawater environment were systematically investigated. The results demonstrate that the 5083Al/Al₂O₃ 3D IPCs retain the inherent corrosion resistance of the 5083Al matrix while exhibiting a substantial enhancement in wear resistance. Compared to monolithic 5083Al, the IPCs showed a 50% reduction in the average friction coefficient (stabilizing at 0.38) and a significantly lower wear volume, which increased only marginally from 3.64 × 10⁻⁹ m³ to 5.14 × 10⁻⁹ m³ as the load rose from 20 to 100 N. This superior performance is attributed to a synergistic mechanism: the exfoliated Al₂O₃ particles form a dense, mechanically mixed layer that protects the surface, while seawater acts as a lubricant. Furthermore, the three-dimensional reticulated alumina ceramic skeleton (Al₂O₃ 3D) effectively bears the applied load, restricts plastic deformation, and impedes the penetration of corrosive Cl⁻ ions, thereby mitigating corrosion-induced wear and lowering the specific wear rate.</p>