Effect of Al on the Tribological Properties of Ni-based Alloys

In this paper, two different alloys of NiCrMo and NiCrMoAl were prepared by high-energy ball milling and vacuum hot press sintering technology. The effects of Al on the microstructure and mechanical properties of alloys, especially its friction and wear properties under different temperature (RT~900 ℃) were studied. The results show that the addition of Al improved both the compactness and hardness of the alloy and the growth of the grain in the sintering process; meanwhile it also reduced the agglomeration of the alloy powders. At high temperatures, the friction-layer on the worn surface of NiCrMoAl alloy was composed of MoO₃, NiO and NiMoO₄, but free of Cr₂O₃ (found on the worn surface of NiCrMo alloy), and rendered good tribological performance.