Tribological behavior of NiAl matrix composites with addition of oxides at high temperatures

NiAl, NiAl-Cr-Mo alloy and NiAl matrix composites with addition of oxides (ZnO/CuO) were fabricated by powder metallurgy route. It was found that some new phases (such as NiZn3, Cu0.81Ni0.19 and Al2O3) are formed during the fabrication process due to a high-temperature solid state reaction. Tribological behavior was studied from room temperature to 1000 degrees C on an HT-1000 ball-on-disk high temperature tribometer. The results indicated that NiAl had high friction coefficient and wear rate at elevated temperatures, while incorporation of Cr(Mo) not only enhanced mechanical properties evidently but also improved high temperature tribological properties. Among the sintered materials, NiAl matrix composite with addition of ZnO showed the lowest wear rate at 1000 degrees C, while CuO addition into NiAl matrix composite exhibited the self-lubricating performance and the best tribological properties at 800 degrees C. (C) 2011 Elsevier B.V. All rights reserved.