(Cr–Al) bi-layer coatings obtained by ion assisted EB PVD on C/C–SiC composites and Ni-based alloys

Cr and (Cr–Al) bi-layers were deposited on carbon reinforced composites (C/C–SiC) and Ni-based alloy substrates by ion assisted EB PVD. The ion current in the substrate region was measured using a special ion detector. Surface morphology of the films was studied using optical, scanning electron, and atomic force microscopy. The variation of the deposited elements was determined by means of a line-scan electron probe on the cross-sections of the samples. Interdiffusion of the deposited elements at the interface was observed. It could have been caused by ‘ion mixing’ during the deposition process. X-ray diffraction (XRD) investigations show the formation of intermetallic compounds Cr3Si andCrAl. Comparative measurements proved that the microhardness of Cr layers on Ni-base alloys, obtained by ion assisted deposition was higher than that of Cr layers deposited without the acceleration of ions.