Investigation on the tribocorrosion and electrochemical corrosion behaviour of AA2014/Al2O3 nanocomposites fabricated through ultrasonication coupled stir-squeeze casting method

• Published in: Journal of applied electrochemistry 2022-04, Vol.52 (4), p.765-791
• Main Authors: Gnanavelbabu, A., Amul, X. Jerish, Surendran, K. T. Sunu
• Format: Article
• Language: English
• Subjects: Aluminum base alloys; Aluminum oxide; Casting; Chemistry; Chemistry and Materials Science; Coefficient of friction; Corrosion; Corrosion resistance; Corrosion tests; Current density; Electrochemical corrosion; Electrochemistry; Electrode polarization; Hardness; Industrial Chemistry/Chemical Engineering; Intermetallic phases; Microstructural analysis; Nanocomposites; Nanoparticles; Physical Chemistry; Pitting (corrosion); Research Article; Squeeze casting
• ISSN: 0021-891X; 1572-8838
• DOI: 10.1007/s10800-022-01666-1

In this work, the tribocorrosion and electrochemical corrosion behaviour of AA2014/Al 2 O 3 (1–4 wt%) nanocomposites were investigated. An unreinforced 2014 alloy and the proposed nanocomposites were prepared through ultrasonication coupled stir-squeeze casting method followed by solutionizing at 510 °C for 2 h and ageing at 165 °C for 16 h. Studies on the dispersion of nanoparticles, intermetallic phase formation, porosity, and hardness were carried out prior to the corrosion analysis. Tribocorrosion test was performed in a linear reciprocating tribometer using 3.5 wt% NaCl solution as electrolyte under potentiodynamic polarization condition for an exposure period of 600, 900, 1200, and 1500 s. A similar testing condition was applied while performing the electrochemical test of materials in a cylindrical beaker. The experimental results indicated a uniform distribution of nanoparticles and the formation of β-CuAl 2 phase in the nanocomposites. A maximum hardness of 150 HV was obtained for the nanocomposite reinforced with 2 wt% of Al 2 O 3 . Tribocorrosion test results indicated that AA2014/3 wt% Al 2 O 3 nanocomposite exhibit the lowest potential of − 0.62 to − 0.68 V with a friction coefficient of 0.15 µ and a minimum current density of 4.889 × 10 –4 at 900 s. The same nanocomposite reduced the removal of metal ions with the lowest potential range of − 0.4 to − 0.5 V and decreased current density of 1.521 × 10 –5 at 1200 s. during the electrochemical test. Alumina hydroxide films and secondary phases caused a superior corrosion resistance at higher exposure times. The microstructural analysis of the corroded surfaces showed pitting corrosion, formation of pits and cracks. Graphical abstract