Comparative analysis of the corrosion resistance of Bos taurus and Cocos nucifera–reinforced 1170 aluminum alloy in chloride-sulfate solution

• Published in: International journal of advanced manufacturing technology 2023-11, Vol.129 (5-6), p.2031-2047
• Main Authors: Loto, Roland Tolulope, Ogunleye, Ademola, Oladipupo, Adeniyi, Ofordum, Sonia, Ale, Abisola
• Format: Article
• Language: English
• Subjects: Aluminum alloys; Aluminum base alloys; Aluminum composites; Aluminum matrix composites; Aluminum oxide; CAE) and Design; Computer-Aided Engineering (CAD; Corrosion potential; Corrosion rate; Corrosion resistance; Electrolytes; Engineering; Industrial and Production Engineering; Intergranular corrosion; Localized corrosion; Mechanical Engineering; Media Management; Open circuit voltage; Original Article; Particulate composites; Pitting (corrosion); Polarization; Scanning electron microscopy; Sulfuric acid; Surface properties; Surface stability; Tribology
• ISSN: 0268-3768; 1433-3015
• DOI: 10.1007/s00170-023-12419-5

Aluminum matrix composites have immense industrial significance due to their excellent mechanical, tribological, and heat-resistant properties. Understanding the corrosion resistance of aluminum composites is highly important for the sustained operational lifespan of the composite. AA1170 aluminum alloy with separate particulate reinforcements of Bos taurus (BT) and Cocos nucifera (CN) (0 to 20% wt concentration) was evaluated for their corrosion resistance properties in 3.5% NaCl and 0.05 M H 2 SO 4 solution by potentiodynamic polarization, open circuit potential analysis, potentiostatic analysis, optical and scanning electron microscopy, and X-ray diffractometry. Result analysis showed corrosion rates of monolithic aluminum alloy (0% particulate wt concentration) from both electrolytes (3.5% NaCl and 0.05 M H 2 SO 4 ) are 0.204 and 0.259 mm/year. Corrosion rate of BT-reinforced composites from both solutions decreased with respect to BT particulate concentration to 0.087 and 0.216 mm/year at 20% BT. Whereas corrosion rate of CN-reinforced composites decreased to 0.161 mm/year in 3.5% NaCl and increased to 0.434 mm/year in 0.05 M H 2 SO 4 at 20% CN concentration. The most passivated aluminum composites from polarization plots occurred at 5% BT and CN particulate concentrations. Increase in particulate concentration increased the vulnerability of the composite to localized corrosion. Open circuit potential plots show particulate reinforcements increased the thermodynamic instability of the surface properties of aluminum composite and its exposure to active-passive transition behavior. Optical and scanning electron microscopy indicates significant improvements in the corrosion resistance of BT and CN particle–reinforced aluminum compared to the unreinforced alloy. Significant surface deterioration, pitting corrosion, and intergranular corrosion were present. X-ray diffractometry showed the phases identified for BT particle–reinforced composite (Al 2 O 3 , Cu S 2, Zn S 2, ZnCO 3 , and CuO 2 ) significantly enhanced its corrosion resistance compared to the unreinforced and CN particle–reinforced composite.