Nghiên cứu chế tạo lớp phủ nanocompozit nhôm oxit có chứa ống nano cacbon (CNTs/Al2O3) bằng công nghệ phun phủ plasma

Abstract

The CNTs/Al₂O₃ nanocomposite coating was made by plasma spraying from nanoscale Al₂O₃ powder mixed with CNTs. Nanosized powders cannot be plasma sprayed owing to its tendency of clogging the plasma gun nozzle. Hence, before spraying, powder treatment is a necessary requirement. In this study, nanoscale Al₂O₃ powder and CNTs (2 wt.%) were combined in Polyvinylalcohol (PVA) binder solution. Spray drying method was used to produce micron-sized Al₂O₃ powder containing CNTs (CNTs/Al₂O₃ powder). The coating morphology, wear resistance, microstructure and phase composition were characterized. The study results showed that, CNTs have clustered into clumps in the CNTs/Al₂O₃ coating. The coating consists of a mixture α-Al₂O₃ and γ-Al₂O₃ phases. In comparison with the Al₂O₃ coating without CNTs, the wear resistance of the CNTs/Al₂O₃ coating is about 20 % higher.