Phase Evolution and Microstructural Behavior in Plasma-sprayed YPO4 Coating upon Thermal Cycling

Atmospheric plasma spray (APS) coating of Yttrium Phosphate (YPO4) may offer excellent environmental durability, outstanding chemical inertness, high melting point, and matching thermal expansion coefficients over a range substrate materials interest. The study investigates for the first time temperature cycling behavior APS YPO4, developed on graphite discs without any bond coat. Generation commonly solid P2O5 in gas phase during development enabling it to acquire some unique properties are few interesting aspects observed. Identifying formation new phases, investigating microstructural changes inside coating, their origin consequences primary interests. Heating coated disk up 1250, 1300, 1350, 1400 °C at rate 12 °C/min, holding temperatures 2 h followed by natural cooling ambient steps cycling. To understand suitability nuclear application, highest cycle is chosen above point Uranium. Induced structural upon investigated using x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) energy-dispersive (EDAX) analysis. Raman spectroscopy Fourier Transform Infrared (FTIR) used further confirm nature developed. Excellent compatibility YPO4 with has been demonstrated °C. Conversion Y2O3 cycling, densification through pore closures, possible improvements barrier strain tolerance capacity due voids results obtained.