Solid particle erosion performance of micro-arc oxidation and electro spark deposition coated Ti6Al4V sheets


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Acar D., Aktuğ S. L., Korkmaz K., Durdu S., Cora Ö. N.

The International Journal of Materials and Engineering Technology, vol.5, no.1, pp.28-32, 2022 (Peer-Reviewed Journal)

Abstract

 In this study, an aerospace-grade Ti6Al4V alloy was coated by micro-arc oxidation (MAO) and 

electro spark deposition (ESD) methods to investigate their effect on solid particle erosion 

performance. The surface morphology and mechanical properties of coatings were characterized by 

SEM and nanoindentation, respectively. Solid particle erosion performance of uncoated and coated 

Ti6Al4V alloy was investigated by using an in-house developed test system per ASTM G76-13 test 

standard. The effect of impact velocity (70 and 150 m/s) on erosive wear was examined using 

angular-shaped SiC erodent particles. The SEM analyses indicated the formation of cracks on 

coated surfaces after erosion tests. The MAO coatings’ surface was rough and porous due to plasma 

chemical reactions on micro discharge channels. In addition, the nature of the ESD method resulted 

in deposits having rough surfaces owing to the rapid solidification of melted electrode and substrate 

materials under atmospheric conditions. Surface topography and crater depths were determined 

using a surface profilometer. Erosion rate was found to be increased with increasing impact velocity 

due to increased kinetic energy of erodent particles. Both MAO and ESD coated samples showed 

worse erosion performance compared to base Ti6Al4V material considering volumetric and 

gravimetric wear rates