M. T. Basha G - Vellore Institute of Technology, Vellore-۶۳۲۰۱۴, Tamilnadu, India
V. Bolleddu - Vellore Institute of Technology, Vellore-۶۳۲۰۱۴, Tamilnadu, India

The microstructural characteristics, mechanical properties, and wear characterization of air plasma sprayed coatings obtained from Carbon nanotubes (CNTs) reinforced Al۲O۳-۳wt%TiO۲ powders were examined at different loading conditions and different percentage proportion of CNTs. The CNTs in the proportion of ۲, ۴, and ۶wt% were used as nanofillers to modify the properties of coatings. The uniform dispersion of CNTs throughout the powder particles can be observed from the SEM micrographs. The porosity of the microstructure of the coatings was measured by image analysis. Also, the mechanical properties such as microhardness and surface roughness were measured by microhardness tester and profilometer, respectively. The wear tribometer was used to analyze the tribology of the coatings by varying different parameters. The different loading conditions used were low load (۰.۵ kgf), moderate load (۱.۰ kgf), and elevated load (۱.۵kgf), respectively. The microhardness showed a slight increase with an increase in the percentage of CNTs proportion. Similarly, the surface roughness value showed a decreasing trend, since the CNTs were filled in the pores. From wear tests, it was observed that the coefficient of friction and wear rate were very less at ۶wt% CNTs and ۱.۵kgf load. This was mainly due to the bridging of CNTs in between the splats. This implies that CNTs were one of the most suitable additives for improving the microstructural and tribological characterization of the ceramic coatings.

Carbon nanotubes (CNTs), Wear Behavior, Coefficient of Friction (COF), CNT bridging.