Transmission electron microscope observations of the wear tracks of nickel and nickel-based alloys tested in a simulated face seal

The fine structural details of the wear tracks of nickel, nickel-chromium and nickel-molybdenum alloys tested in a simulated face seal apparatus have been observed using transmission electron microscopy. The structures are complex and varied; there are regions of extremely high dislocation density and in all materials recrystallization is prevalent, with a very fine grain size (0.1 μm or less). The nickel-molybdenum alloys had been heat-treated to develop either an ordered or a disordered structure and changes in this due to the wear process showed that in some cases the local interface temperature exceeded 900 °C.