HVOF-Sprayed Al2O3-TiO2 Coatings Using Hybrid (Nano+Submicron) Powders:an Enhanced Wear Performance

摘要

In previous studies, it has been demonstrated thatnanostructured Al2O3-13wt%TiO2 coatings deposited via airplasma spray (APS) exhibit higher wear resistance whencompared to that of conventional coatings. This study aimedto verify if HVOF-sprayed Al2O3-13wt% TiO2 coatingsproduced using hybrid (nano+submicron) powders couldimprove even further the already recognized good wearproperties of the APS nanostructured coatings. According tothe abrasion test results (ASTM G 64), there was animprovement in wear performance by a factor of 8 for theHVOF-sprayed hybrid coating as compared to the bestperforming APS conventional coating. When comparing bothhybrid and conventional HVOF-sprayed coatings, there wasan improvement in wear performance by a factor of 4 whenusing the hybrid material. The results show a significant antiwearimprovement provided by the hybrid material. Scanningelectron microscopy (SEM) at low/high magnificationsshowed the distinctive microstructure of the HVOF-sprayedhybrid coating, which helps to explain its excellent wearperformance.