Evolution of porosity in suspension thermal sprayed YSZ thermal barrier coatings through neutron scattering and image analysis techniques
نویسندگان
چکیده
Porosity is a key parameter on thermal barrier coatings, directly influencing conductivity and strain tolerance. Suspension high velocity oxy-fuel (SHVOF) spraying enables the use of sub-micron particles as feedstock, increasing control over porosity introducing nano-sized pores; these fine-scale porosities being challenging to measure. Neutron scattering represents non-destructive technique, capable studying with pore size range 1 nm 10 um, thanks combination small-angle (SANS) ultra-small-angle neutron (USANS) techniques. Image Analysis (IA) digital images allows for study above ~100 nm. In this work, two yttria-stabilised zirconia (ZrO2 8 wt.% Y2O3) suspensions were sprayed heat treated at 1100, 1200, 1300 1400 {\deg}C 72 h. For first time in SHVOF 8YSZ, distribution, total morphology studied using SANS & USANS IA determine effects treatment. X-ray diffraction micro-hardness measurements performed phase transformation, its mechanical properties coating. The results show an abundant presence nano-pores as-sprayed which are eliminated during treatment 1100 {\deg}C; transition from inter-splat lamellar pores globular appearance micro-cracks along accumulation micro-strains associated transformation initial metastable tetragonal into cubic phases 1200 {\deg}C. was completed {\deg}C, no monoclinic
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ژورنال
عنوان ژورنال: Journal of The European Ceramic Society
سال: 2021
ISSN: ['0955-2219', '1873-619X']
DOI: https://doi.org/10.1016/j.jeurceramsoc.2021.04.020