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The fabrication of aluminium AA7075 and AA7075/SiC composite foams employ the stir casting method, incorporating calcium carbonate (CaCO3) as a blowing agent at a concentration constituting 2.5wt. % of the alloy. Notably, no viscosity-enhancing component was included in the process. The compressive parameters, including the yield strength (σc), plateau stress (σpl) and energy absorption (Eab), of the foam materials were examined to investigate the influence of Silicon Carbide (SiC) on the microstructure, namely the cell size and cell wall thickness. The incorporation of Silicon Carbide particles (SiC) into the cell wall imparts enhanced hardness and strength. The findings indicate that the inclusion of SiC particles may enhance the mechanical properties like σc, σp and Eab, of composite foams. The porosity of the composite foam increases from 59.07% to 68.68% with the incorporation of SiC particles. The cell dimensions fluctuated between 1.12 and 1.45mm as the relative density of the AA7075/SiC composite foam decreased from 0.4 to 0.31. [ABSTRACT FROM AUTHOR]

In this study, AA7075/SiC/TiB2 closed-cell aluminium hybrid composite foams (AHCFs) with different densities were fabricated by top-loaded bottom-pouring stir casting technique. This technique uses oyster-shell powders (CaCO3 2.5 wt% of composite with 60 μm size) as blowing agents and no viscosity-enhancing ingredient. The silicon carbide (SiC 0, 3, 6, 9, and 12 wt% with 25 μm) and titanium diboride (TiB2 3 wt% with particle size 15 μm) are used as primary and secondary reinforcement agents. It has been noted that the addition of TiB2 and SiC enhanced the mechanical properties (modulus of elasticity, yield strength, and plateau strength) of AHCFs. The energy absorption capacity of AHCFs increases with the addition of SiC up to 3 wt%, and a further increase in SiC content leads to the reduction. It is observed that density and cell wall thickness increase with increasing the wt% of SiC and pore size, porosity decrease with an increase in wt%. of reinforcement. It is also noted that stirring temperature also strongly influenced the microstructural properties of AHCFs, and 750 °C of stirring temperature is sufficient for aluminium foaming. [ABSTRACT FROM AUTHOR]

Aluminium foams have been manufactured and discovered to have a variety of uses in automotive and structural applications. However, due to their varied characteristics, it is difficult to choose an appropriate material. In this context, the selection of material for good properties is a challenging task. This study attempted to identify materials from various combinations employing the Multiple Attribute Decision Making (MADM) technique based on their mechanical and physical properties. Complex Proportional Assessment (COPRAS) is a Multi-Criteria Decision Making (MCDM) technique employed for evaluating the ranking order of the aluminium composite foam’s formulations based on performance measures. The composite foam with 2.5 wt.% of Calcium carbonate as foaming agent demonstrated the best combination of mechanical properties. [ABSTRACT FROM AUTHOR]

Metallic foams are popular due to their high strength-to-weight ratio. Moreover, foams are excellent vibrations damper, which attracted attention of researchers. This study investigated the improvements in the characteristics of metal foams for the structural applications. The metal foams were fabricated by stir casting method using calcium carbonate (CaCO3) as foaming agent. The metallic foam generated are aluminium hybrid composite foam (AHCF) with densities varying between 0.88 and 1.14 g/cc. Developed AHCF was characterised for their physical and mechanical properties like density, porosity, three-point bending, compression and hardness followed by microstructural investigation. Results show that the percentage of the weight (wt.%) of the foaming agent plays a significant role in deciding the density, compressive strength, bending strength and the hardness of AHCF. The study reveals that compressive strength, flexural strength and the hardness of AHCFs increased with their density. AHCF exhibits lower density and higher specific strength when compared to aluminium (AA7075). [ABSTRACT FROM AUTHOR]