Microstructure and properties of in situ nanostructured ceramic matrix composite coating prepared by plasma spraying

摘要

In situ nanostructured ceramic matrix composite coating toughened by metallic phase was fabricated by reactive plasma spraying micro-sized Al–Fe2O3 composite powders. The microstructure of the composite coating was characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, respectively. The adhesive strength, microhardness, toughness, and wear resistance of the composite coating were explored. The results indicated that the composite coating exhibited dense microstructure with a lot of spherical α-Fe and γ-Al2O3 nano-sized grains embedded within the equiaxed and columnar FeAl2O4 nano-grains matrix. The adhesive strength, toughness, and wear resistance of the composite coating were significantly enhanced despite its lower microhardness compared with the micro-sized Al2O3 coating, which were attributed to the inclusion of ductile metallic phase Fe in the composite coating and the nanostructure of the composite coating.