TIO2 COATINGS ON RED CLAY SUBSTRATES BY THERMAL SPRAYING

Abstract

The structure, mechanical and tribological performance of TiO2 (Sulzer Metco 102) on red clay substrates by oxy-fuel thermal spraying process was evaluated. The ceramic substrates were manufactured by uniaxial pressing at 26.2 bar, and sintered at 1100 °C. TiO2 coatings were grown with 5, 9 and 14 passes or cycles of the oxyacetylene flame on the substrate. The structure was studied using X-ray diffraction (XRD, Bruker D8 Advance) and scanning electron microscopy (SEM, FEI Quanta 650 FG); the mechanical resistance to bending and wear by abrasion deep, were studied using ISO standards 10545-4 and ISO10545-6 respectively; adhesion was measured using Elcometer equipment Type III according to ASTM D-4541-02 and the average roughness (Ra) was found according to ASTM standard D7127-13, using the profilometer Mitutoyo SJ 201. The results indicate that the TiO2 rutile phase was formed with a heterogeneous surface morphology of molten splats, with Ra of 4.7 ± 1.1 microns for the substrate, increased to 22.6% for the thicker sample, of the adhesion tests can be inferred that the adhesion of the coating is greater than the values reported, because adhesion failure occurs by the substrate.