Effect of electron beam remelting on the characteristics of HVOF sprayed Al2O3-TiO2 coatings deposited on titanium substrate

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2017-08, Vol.526, p.70-75
• Main Authors: Utu, I.D, Marginean, G.
• Format: Article
• Language: English
• Subjects: Corrosion behaviour; HVOF sprayed coatings; Sliding wear resistance
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2016.10.034

[Display omitted] •HVOF sprayed ceramic coatings (Al2O3+13wt.% TiO2) were deposited onto the surface of a titanium substrate.•To improve their characteristics the coatings were further remelted by electron beam (EB) remelting.•The coatings properties were evaluated in terms of microstructure, phase composition, corrosion and sliding wear resistance.•EB-remelting of Al2O3-TiO2 coatings surface is a solution for improvement the titanium sliding wear resistance. The primary objective of this study was to improve the wear resistance of titanium by depositing on its surface a HVOF (high velocity oxygen fuel) sprayed Al2O3-TiO2 coating subsequently remelted by electron beam (EB). The microstructure of the feedstock material, as-sprayed and EB remelted coatings was investigated by scanning electron microscopy (SEM) and X-Ray diffraction techniques (XRD). The effect of EB treatment on the coatings characteristics especially concerning the morphology, the hardness respectively the corrosion and wear behaviour was also analysed. The results indicated that remelting process improved the coating properties in terms of porosity, strength and chemical homogeneity. The coating adherence to the substrate was strengthened by means of metallurgical bonding and interdiffusion processes. The sliding wear resistance and the hardness of the coating were significantly higher in comparison with that of the titanium. The densified material obtained after the EB remelting had the highest sliding wear resistance and its corrosion behaviour was not strongly influenced compared with that exhibited by the substrate material.