Abstract

Nanostructured Al 2O 3–13 wt.% TiO 2 coatings were prepared by plasma spraying with agglomerated powders. The microstructural characteristics of the feedstock and the coating were investigated by using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD). Moreover, the microstructural formation mechanism of the coating was analyzed. The results show that the ceramic coating consists of both fully melted regions and partially melted regions, and the fully melted region has a lamellar-like structure as the conventional coating. In terms of microstructures, the partially melted regions can be divided into liquid-phase sintered regions (a three-dimensional net or skeleton-like structure: Al 2O 3-rich submicron particles embedded in the TiO 2-rich matrix) and solid-phase sintered regions (remained nano-particles). The fully melted region, liquid-phase sintered region and solid-phase sintered region of the coating derive from the region of the feedstock, where the corresponding temperature during plasma spraying is beyond 2045 °C (melting point of Al 2O 3), between 1840 °C (melting point of TiO 2) and 2045 °C and below 1840 °C, respectively. The formation of the solid-phase and liquid-phase sintered regions in the partially melted region is attributed to the melting point difference of A1 2O 3 and TiO 2.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.