کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
735370 | 893605 | 2011 | 8 صفحه PDF | دانلود رایگان |
The present paper reports an experimental investigation based on X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and wavelength dispersive spectroscopy (WDS) analyses of phases formed after laser sealing of plasma sprayed coatings of 8.5 wt% yttria partially stabilized zirconia (YPSZ). X-ray diffraction and X-ray step-scanning analyses showed that the plasma sprayed and sealed coatings consisted mainly of t′ phase with a very small amount of monoclinic phase (m phase) in the plasma sprayed coatings. It was also found that the small amounts of m and cubic phases (c phase) present in the sealed coatings were dependent on laser processing specific energies (specific energy is equal to laser power/traverse speed x beam diameter). It was also found that rhombohedral (r) phase formed after laser sealing of coatings at higher specific energies. A direct relationship between c/a ratio of transformable tetragonal phase (t phase) produced by thermal treatment of sealed coatings and nontransformable tetragonal phase (t′ phase) and the amount of Yttria was obtained. A new equation was derived, which describes the relationship between Yttria concentration and the c/a ratio of tetragonal phases (t or t′).
► I report the effect of laser parameters on phases formed on plasma sprayed YPSZ.
► The main phases are mainly nontransformable tetragonal (t′) and rhombohedral (r).
► Increasing the specific energy slightly decreases the proportion of t′ phase.
► I obtain a new equation between wt% Y2O3 and the c/a ratio of tetragonal phases.
► The data suggest the following equation: wt% Y2O3=408.4–396.7 c/a±0.2 wt%.
Journal: Optics and Lasers in Engineering - Volume 49, Issue 7, July 2011, Pages 785–792