Influence of surface physicochemistry and morphology of TA6V substrates on the mechanical resistance of thin layers of alumina

Substrate surface preparation before chemical vapor deposition is an important step for the adhesion. This study describes the influence of the temperature and the RF bias during in-situ argon plasma treatment on TA6V substrates just before Plasma Enhanced Chemical Vapor Deposition (PECVD) of alumina. Substrates were treated under oxygen plasma without introducing aluminum precursor during 90 seconds under process PECVD conditions that were later used for coatings development. The surface of the samples is analyzed by Electron induced X-ray Emission Spectroscopy to study the physicochemical environment around the aluminum atoms. Atomic Force Microscopy (AFM) allowed to show the treatment impact on the surface morphology of the substrates. Coatings were characterized by the multicracking 4-point bending test. The results pointed out that the polarization value has a minor effect, whereas the temperature has a major influence.