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1202 |
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Wednesday, June 04, 2008, Room 05 11:00 AM Characterization 2 Modern characterization offers a good possibility for proofing the reliability and the performance of thermal sprayed coatings |
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Characterization of nanostructured and conventional alumina?13wt.% titania coatings |
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Ahmed Ibrahim* / Farmingdale State College, USA Hanadi Salem / American University in Cairo, Department of Mechanical Engineering, Egypt Christopher Berndt/ James Cook University, School of Engineering, Australia |
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Nanostructured and conventional alumina?13wt.% titania powders were thermally sprayed using high velocity oxy-fuel (HVOF) process. Scanning electron microscopy (SEM) was used to examine the morphology of the agglomerated powders and the cross section of the alumina-titania coatings. The microstructure and phase composition of the coatings were characterized by X-ray diffraction (XRD), and scanning electron microscopy. Detailed SEM examination at high resolution revealed a significant difference between the conventional and nanostructured alumina/titania coatings. The fatigue and mechanical properties of the coatings were investigated. SEM analyses were also carried out on the fracture surfaces of fatigue-tested samples to assess the mechanisms of deformations. The experimental data indicated that the nanostructured coated samples exhibited higher stiffness, hardness, and fatigue strength compared to the conventional coated samples. |