Development of amorphous and CNT-reinforced amorhpous 3eramic coatings fabricated by plasma spraying process

The plasma-sprayed amorphous ceramic coating and CNT-reinforced amorphous ceramic coating were successfully developed by plasma spraying process. Also, the microstructure, mechanical, and chemical properties of the plasma-sprayed amorphous ceramic coating and CNT-reinforced amorphous ceramic coating were systematically investigated. The formation mechanism of plasma-sprayed amorphous ceramic coating was involved with rapid quenching of the fully melted ceramic splats via ultra-high-temperature of plasma jet. The plasma-sprayed amorphous ceramic coatings showed the characteristic lamellae microstructure composed of individual splats containing rare microcracks and microvoids. The mechanical and chemical properties of the plasma-sprayed amorphous ceramic coating were effectively improved from the plasma-sprayed crystalline ceramic coatings, such as Al₂O₃ and Y₂O₃. Moreover, the plasma-sprayed CNT-reinforced amorphous ceramic coating characterized by a nanocomposite comprising uniformly dispersed CNTs embedded in amorphous ceramic matrix. The mechanical properties of plasma-sprayed CNT-reinforced amorphous ceramic coating, such as micro-hardness, elastic modulus, fracture toughness, and wear resistance were increased with increasing the uniformly dispersed CNTs addition compared to those of plasma-sprayed bare amorphous ceramic coating without CNT addition.