Fabrication and Property Evaluation of the Al2O3-TiO2 Composite Coatings Prepared by Plasma Spray

Abstract

The Al2O3-13 wt.% TiO2 (AT13) composite coatings were prepared on Q235 steel by plasma spray technique. The spray parameters were designed by the orthogonal experiments, and the properties of the coating were evaluated. Results showed that with respect to the bond strength of the coating, the optimized spraying parameters were the plasma current of 530 A, Ar flow of 41 L/min, H2 flow of 10 L/min, and spray standoff distance of 100 mm. The plasma spray process led to the transition of α-Al2O3 to γ-Al2O3, resulting in the increase in the porosity of AT13 coating prepared at nonoptimized parameters. Meanwhile, the porosity and cracks were also increased due to the decrease in the Ar flow and the increase in spray standoff distance. The low porosity, a few cracks, and the uniformly dispersed TiO2 particles contributed the enhanced properties including mechanical and corrosion behaviors of the AT13 coating prepared at optimized parameters. The bond strength, microhardness, and thermal shock resistance of the AT13 coating could reach 25.01 MPa, 1000.6 HV0.5, and 40 times when the coating was prepared at optimized parameters, respectively. Especially, the static Icorr of the AT13 coating prepared at optimized parameters was two order of magnitude less than that of Q235 steel. In addition, the erosion weight loss of Q235 steel could be decreased about 30 times by the protection of the AT13 coating.

Cavitation Erosion and Wet Environment Tribological Behaviour of Al2O3-13% TiO2 Coatings Deposited via Different Atmospheric Plasma Spraying Parameters

“…1). Naturally, the splat-like morphology of the deposited Al 2 O 3 -13% TiO 2 material is created for APS spraying, which is comparable to those reported by the literature [23,25]. Moreover, surface oxidization, open porosity, not completely melted solid material particles, and cracks can be found.…”

Development of Alumina-Titania Composite Layers on Stainless Steel through the Detonation Spray Method and Investigation of Salt Spray Corrosion Behavior along with Surface Examination

“…Tis fact indicated that alumina and titania interacted with each other to form an alumina-titania composite. Besides aluminatitania, alumina, titania, and SS could also be detected in the coating through their peaks [34]. Tis fact revealed that some alumina and titania could not react with each other and remain in their original form.…”

Plasma Spraying of a Microwave Absorber Coating for an RF Dummy Load

“…The copper particles that can be found within coating are due to preparative restraints during cross section polishing treatment. In the optical microscope image, shown in Figure 9a, and SEM images, shown in Figure 9b, dark areas represent Al2O3 rich phases, whereas bright areas represent TiO2 rich phases and stoichiometric solid solution of Al2O3 and TiO2 [15]. .…”