Densification and tribological profile of niobium oxide.

The origin of the intrinsic wear resistance of NbC-based materials is investigated through an assessment of the tribological performance of fully dense, crack-free spark plasma sintered Nb 2 O 5 (here as a reduced polymorph: monoclinic Nb 12 O 29 or NbO 2.416 ). The most likely wear mechanism on NbC is the tribo-oxidation to Nb 2 O 5 . The unlubricated (dry) friction and wear behavior of alumina (99.7%) mated against rotating disks of crack-free niobium(V)oxide (Nb 2 O 5 ) under unidirectional sliding (0.03–10 m/s; 22 °C and 400 °C) and oscillation ( f =20 Hz, dx=200 mm, 2/50/98% rel. humidity, n =10 5 /10 6 cycles) will be presented. The microstructure and mechanical properties of the crack-free Nb 2 O 5 are assessed. The tribological data obtained are benchmarked with different NbC grades, ceramics, cermets and thermally sprayed coatings. [ABSTRACT FROM AUTHOR]