Tribological behavior of plasma sprayed carbon nanotube (CNT) reinforced aluminum oxide (Al 2 O 3 ) composite coatings was examined at room temperature, 573 K and 873 K using tungsten carbide (WC) ball-on-disk tribometer. The weight loss due to wear of Al 2 O 3 coating was found to be increasing with the temperature while Al 2 O 3 -CNT coating showed a decreasing trend in the weight loss with the temperature. Relative improvement in the wear resistance of Al 2 O 3 -CNT coating compared to Al 2 O 3 coating was found to be 12% at room temperature which gradually increased to ∼ 56% at 573 K and ∼ 82% at 873 K. Protective layer as a result of tribo-chemical reaction was observed on the wear track of both of the coatings. The improvement in the wear resistance of Al 2 O 3 -CNT coating was attributed to three phenomena viz. (i) higher hardness at the elevated temperature as compared to Al 2 O 3 coating, (ii) larger area coverage by protective film on the wear surface at the elevated temperature and (iii) CNT bridging between splats. The coefficient of friction (COF) of Al 2 O 3 coating was nearly constant at room and elevated temperature whereas COF for Al 2 O 3 -CNT coating decreased at the elevated temperature (873 K). © 2009 Elsevier B.V. All rights reserved.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below