Nanostructured ceramic composite coatings were deposited byhigh velocity arc-spraying. It was found that metal-cladpowders exhibited better thermal conductivity and atomizationcapabilities when compared to mechanically blended powders.The Surface Rockwell hardness values of the nanostructuredceramic composite coatings were similar to those of theconventional coatings (from 66.7 to 72.8), however, the bondstrength of the nanostructured coatings measured via theGB9796-88 standard reached values of 60 Mpa, whereas thebond strength of the conventional coatings stayed below 40Mpa. The microstructure of the high velocity arc sprayednanostructured ceramic coatings was analyzed using X-raydiffraction (XRD) and scanning electron microscopy (SEM).The coatings exhibited the typical lamellar structure of thermalspray coatings. The surface of the nanostructured compositecoatings was smoother than that of the conventional ones, andtheir microstructures were denser, showing lower levels ofimpurity.
展开▼
