Three kinds of nanostructured alumina coatings were prepared by air plasma spraying (APS). The microstructure of these coatings was characterized by SEM and X-ray diffraction (XRD). The surface roughness, porosity and microhardness of as-sprayed coati...
Three kinds of nanostructured alumina coatings were prepared by air plasma spraying (APS). The microstructure of these coatings was characterized by SEM and X-ray diffraction (XRD). The surface roughness, porosity and microhardness of as-sprayed coatings were measured. The results indicated that the smaller the size of starting powder was. The better properties the coating possessed. The differences among phase analysis of these as-sprayed coatings could explain it.