Tribological Characteristics of Nanostructrued Ceramic Coatings Deposited by Plasma Spraying

Nanostructured Al2O3-13wt.% TiO2 coatings were prepared by plasma spraying using agglomerated nanocrystalline powders via a spray drying method. The as-sprayed coatings and their worn surface were characterized using scanning electron microscope (SEM). The tribological characteristics were evaluated on block-on-ring configuration. It is found that that the nanostructured coating exhibited a unique bimodal microstructure, which has an important influence on the tribological characteristics. The abrasive wear resistance of the nanocoatings are greatly improved compared with the conventional coatings, and the abrasive wear mechanism is also discussed.