Crystalline ytterbium disilicate environmental barrier coatings made by high velocity oxygen fuel spraying

Abstract Dense environmental barrier coatings (EBCs) are an essential prerequisite to exploit the advantages offered by SiC‐based fiber reinforced ceramic matrix composites (CMCs) increase efficiency in gas turbines. Today's state‐of‐the art materials for application as EBCs rare‐earth (RE) silicates which, however, form amorphous phases upon rapid quenching from melt. This makes their processing thermal spray a challenge. Recently, high velocity oxygen fuel (HVOF) spraying was proposed potential solution since melting degree of feedstock can be controlled effectively. work studies deposition ytterbium disilicate (YbDS) at short stand‐off distances and variant total feed rates oxy‐fuel ratios working gas. It found that overall crystallinity could kept level above 90%. The kinetic energy transferred impinging particles effective parameter control densification coatings. Porosities well below 10% were achieved while fully dense impeded due progressive accumulation stresses