Influence of CaCO₃ and Al₂O₃ on the Mechanical Properties of Aluminum Foam for Lightweight Structural Applications

This paper discusses the fabrication and mechanical properties of Aluminum foams, using CaCO₃ as a blowing agent and Al₂O₃ as a thickening agent. Aluminum foams are well-known for their low weight, high compressive toughness, and excellent energy absorption in applications such as lightweight structures, automotive, aerospace, and sound absorption, where a high-performing, lightweight material is required. Five compositions of CaCO₃ and Al₂O₃, such as 1 to 3 wt %, were used in this research to produce aluminum foams using a liquid metallurgy route. Microstructural analyses by SEM, EDS, and XRD revealed the effect of composition on pore size, distribution, and intermetallic formation. A full factorial experimental design was used to assess each composition for compressive strength, impact energy absorption, wear rates, micro Vickers hardness, and corrosion resistance. The best mechanical performance was found in composition AF02 (3% CaCO₃, 1% Al₂O₃), which has high energy absorption and compressive strength, while AF05 (2% CaCO₃, 2% Al₂O₃) shows the best corrosion resistance and wear rate. The balanced addition of CaCO₃ and Al₂O₃ improves foam stability and structural integrity. However, increased wear and temperature-induced performance loss suggest areas for further refinement. The present research investigates optimization issues in aluminum foams and provides a pathway to advanced material development for demanding engineering applications.