Wear Behavior of Plasma-Sprayed Carbon Nanotube-Reinforced Aluminum Oxide Coating in Marine and High-Temperature Environments
Wear behavior of plasma-sprayed carbon nanotube (CNT)-reinforced aluminum oxide (Al2O3) composite coatings are investigated at room temperature (298 K), elevated temperature (873 K), and in sea water. Lowest wear volume loss was observed in the sea water as compared to dry sliding at 298 and 873 K. Relative improvement in the wear resistance of Al2O3-8 wt.% CNT coating compared to Al2O3 was 72% at 298 K, 76% at 873 K, and 66% in sea water. The improvement in the wear resistance of Al2O3-CNT coatings is attributed to (i) larger area coverage by protective film on the wear surface at room temperature and in sea water, (ii) higher fracture toughness of Al2O3-CNT coatings due to CNT bridging between splats, and (iii) anti-friction effect of sea water. The average coefficient of friction (COF) was the lowest (0.55) in sea water and the highest (0.83) at 873 K for Al2O3-8 wt.% CNT coating.
Keywordscarbon nanotube friction and wear nanocrystalline composites nanopowders nanostructured coatings plasma spraying wear mechanisms
The authors acknowledge the financial support received from the Office of Naval Research (N00014-08-1-0494). AKK acknowledges support from the Dissertation Year Fellowship by the University Graduate School of Florida International University (FIU). The authors are also grateful to the Center for the Study of Matter at Extreme Conditions (CeSMEC), FIU for allowing them to carry out Raman spectroscopy, and the Advanced Materials Engineering Research Institute (AMERI), FIU to avail the scanning electron microscopy facility.
- 2.E.H. Jordan and M. Gell, Nano Crystalline Ceramic and Ceramic Coatings Made by Conventional and Solution Plasma Spray, Nanomaterials Technology for Military Vehicle Structural Applications, RTO-MP-AVT-122, 3-4 October, 2005Google Scholar
- 25.FACTSAGE, Thermodynamic Equilibrium Software, Version 5.0, Center for Research in Computational Thermochemistry of the Ecole Polythechnique at the Université de Montréal and GTT-Technologies, GmbH, Aachen, Germany, 2001Google Scholar
- 30.A.G. Evans and B. Marshall, Wear Mechanism in Ceramics, Fundamentals of Friction and Wear of Materials, D.A. Rigney, Ed., ASM International, Metals Park, OH, 1981, p 439-452Google Scholar