Rare earth-doped ceramic coatings: Analysis of microstructure, mechanical properties, and slurry Erosion resistance using high pressure-high velocity oxy-liquid fuel deposition

Abstract

The high pressure-high velocity oxy liquid fuel (HP-HVOLF) is a current industry-adopted thermal spraying technique for developing high melting point powder coating over surfaces. In the current manuscript, the rare earth (La₂O₃/CeO₂/Er₂O₃–0.3 wt%. each) doped and without rare earth doped carbide (WC-10Co-4Cr) coatings have been deployed on stainless steel (SS410) via HP-HVOLF process. The comparison among the properties of the substrate, without rare earth coating and rare earth oxides doped coatings have been characterized by conducting mechanical, microstructural, and slurry jet erosion analysis. The results show that the hardness, modulus of elasticity, and flexural strength of the cermet coating are considerably higher for rare earth-doped coatings than those without rare earth-doped coatings and substrates (SS410). The EDX (energy dispersive X-ray spectroscopy) has recognized the occurrence of different elements on the surface together with rare earth. Moreover, its compounds such as Co₃W₃C and W₂C were inveterate using X-ray diffraction (XRD) measurements. The porosity level of the rare earth doped, and un-doped coatings are obtained to be less than 1 % and≥1 to ≤2 % respectively. Moreover, the rare earth-doped cermet coated surface shows hydrophobic behavior with a maximum water contact angle (WCA) of ≈129.4°. Furthermore, the slurry jet behavior of rare earth doped coating shows high wear resistance as compared to without RE doped coatings, indicating its potential for robust performance under erosive conditions.