Tribological Characteristics of Tantalum-Oxide Coating Fabricated on Pre-Treated 2024 Aluminum Alloys

Aluminum has many advantages, such as being lightweight, but it may not provide sufficient wear resistance for some applications. Tantalum oxide is a ceramic-based coating layer that can improve wear resistance. In this study, 2024 aluminum alloy samples with different surface treatments were coated with amorphous Ta₂O₅ using the RF spraying method under the same conditions. Polishing, 10% HCl solution, 5% NaOH solution, and 50% HNO₃ solution, as well as sandblasting, were applied to the surfaces of aluminum alloys separately, and the sample groups were coated. The effects of pre-coating surface treatments on coating morphology and wear resistance were investigated. The surface morphologies of the coatings were examined using scanning electron microscopy, electron dispersion spectroscopy, and X-ray diffraction. Wear tests were then conducted to determine the mechanical properties, and after the tests, scanning electron microscopy examinations and volume loss calculations were performed using a profilometer. The wear test results were discussed and compared. The investigation yielded continuous, homogeneous, and crack-free coatings on the 2024 aluminum alloy surfaces. However, the wear resistance of these coatings was compromised by acid etching. Following polishing and sandblasting, the coated surfaces experienced a decrease in volume losses from abrasion by 4.3% and 44.8%, respectively, compared to the uncoated samples.