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.