Tribological evaluation on Ni3Al-based alloy and its composites under unlubricated wear condition

▶ The selected single phase NAC-alloy in this work has the almost same friction coefficient and specific wear rate under the testing condition, comparing to a commercial vermicular cast iron used in ship engines. The wear mechanism is most probably conducted to its intrinsic deformation mechanism of the Ni3Al-type of intermetallics. ▶ Unfortunately, the single phase NAC-alloy was not working with its counterpart grey cast iron disk inadequately. Therefore, the monolithic NAC-alloy material shall not be applied to a certain wearing condition. But, it can probably be suitable as a matrix material to develop wear-resistant composites. ▶ 6 vol.% MnS-particle addition, as an effective solid lubricant, dramatically improved specific wear rate of the grey cast iron disk, and also friction coefficient of the friction-pair. But, its specific wear rate is remained as the same as the monolithic NAC-alloy and the reference vermicular cast iron. ▶ Definitely, 6 vol.% added Cr3C2 hard particles reduced wearing on both sides of pin and disk, up to 50%. It was considered that the hard Cr3C2-asperities kept the sliding surfaces apart, when the matrix part was worn off during the wearing process, then reducing the specific wear rates of both pin and disk. The phenomenon was more obvious under an applied high load of 40 N testing condition.