The AA2024 alloy, widely used in the aerospace industry due to its high strength-to-weight ratio, is susceptible to wear and corrosion, which limits its durability. Developing effective methods to protect AA2024 from these degradation factors is an urgent task. One promising approach is the application of protective coatings, in particular, AlCuFe alloys.
AlCuFe alloys, which have high hardness, wear resistance and corrosion resistance, are promising materials for protecting AA2024. Applying thin layers of AlCuFe to the surface of AA2024 can significantly improve its performance in aggressive environments.
Various methods can be used to apply AlCuFe coatings to AA2024, including plasma spraying, magnetron sputtering, and laser machining. Each method has its own advantages and disadvantages that affect the microstructure, adhesion, and protective properties of the coating.
The resulting AlCuFe coatings are characterized by high hardness and wear resistance, which significantly reduces the wear rate of AA2024. In addition, AlCuFe forms a passive layer on the surface, providing effective protection against corrosion in various aggressive environments, including salt solutions and atmospheric conditions.
The use of AlCuFe spraying to protect AA2024 alloy from wear and corrosion opens up new possibilities for increasing the durability and reliability of structures operating in extreme conditions. This approach can be applied in the aviation, space, automotive and other industries where high wear resistance and corrosion resistance of materials are required. Further research is aimed at optimizing spraying methods and developing new AlCuFe alloys with improved protective properties.
A coating of quasi-crystalline material (QC) AlCuFe was formed on the surface of AA2024 alloy using high-velocity air-fuel (HVAF) spraying technology. The obtained HVAF coatings were examined both in the initial form and after heat treatment (400°C, holding for 1 hour). The methods of X-ray phase analysis, scanning electron microscopy and energy-dispersive X-ray spectroscopy showed the presence of a two-component microstructure represented by an icosahedral ψ-phase (approximately 75% by volume) and a lamellar β-phase similar to the phase composition of the AlCuFe powder obtained by water atomization and used as a raw material. It was found that the applied annealing has virtually no effect on the protective characteristics of the HVAF coating, which demonstrates high adhesion strength to the base (more than 12 MPa), increased microhardness HV (7.1±0.2 GPa), nanohardness (11.1±0.2 GPa), Young’s modulus (169 GPa), significantly reduced wear (0.71 μm), low friction coefficient (CoF≈0.03) and low corrosion current density (6.7 μA/cm-2) in 3.5% NaCl solution. The listed properties significantly exceed similar parameters of the original AA2024 alloy.
Author: Changliang Wang Zhang Li, Nikolay O., and Bogdan N. Mordyuk
Institute: G.V. Kurdyumov Institute of Metal Physics of the National Academy of Sciences of Ukraine, Academician Vernadsky Boulevard, 36, Kyiv, UA-03142, Ukraine