Direct and Indirect Cavitation-Erosion Assessment of Cold Sprayed Aluminum Alloy/Quasicrystals Composite Coatings: Poster

Aluminum alloys are widely recognized for their extraordinary characteristics, such as their lightweight composition and resistance to corrosion. These alloys play a crucial role in several industrial branches, including aerospace, automotive, and marine sectors. However, it is important to recognize the potential risks associated with cavitation-erosion damage, despite the advantages mentioned earlier. Potentially, the strengthening of Al-matrix by a second phase can offer a practical solution towards the increase of cavitation erosion resistance. Cold spray (CS) technology, with the ability to create dense and high-quality Al-based composite coatings, can act as a promising route to address this challenge. Moreover, CS technology allows for repairing the damaged surfaces, reviving components that would otherwise require costly replacement. In our previous studies on CS Al alloys reinforced by Al-based quasicrystalline (QC) materials, fabricating dense and integrated composites was found to be successful. The improved structure and dry sliding wear behavior of the CS Al-QC composite coatings added an incentive to conduct current experimental work; this study aims to provide a comprehensive understanding of CS Al-QS cavitation-erosion behavior via direct and indirect testing methods using vibratory ultrasonic apparatus immersed in distilled water. Accordingly, composite coatings were generated by high pressure cold spraying of AA 6061 premixed with QC powders with 50 and 90 vol%. By implementing cavitation-erosion tests followed by a comprehensive set of microstructural characterization, the samples were ranked in terms of cumulative mass loss, volume loss, maximum depth of damage and erosion rate with respect to the unreinforced CS AA 6061. Additionally, residual stress accommodation due to cold spraying of mixed feedstock with varying hard phase reinforcing content (QC) was investigated and correlated with the cavitation erosion resistance of the CS composite coatings. Based on microstructural studies, the underlying mechanism of the damage was probed and influencing testing factors were discussed. Alongside the ranking of the coatings, this work provides a baseline for comparison and understanding of correlation between direct and indirect cavitation-erosion for cold sprayed coatings according to the ASTM G32-2021 standard.