Ultrafine-grained Al-CNT (2 and 4 vol%) composites were successfully fabricated using the flake powder metallurgy
and hot pressing route, and the microstructure and tribological properties of the produced composites
were studied. The results showed that the coefficient of friction and the wear rate of Al decrease with the
addition of the CNT reinforcement. A carbon-rich film formed on the worn surfaces during wear test, which
prevented the Al oxidation and yielded the self-lubricating effect for the composites. This improvement in the
wear behavior of the composites can be attributed to the simultaneous effects of the ultrafine-grained matrix and
strengthening and self-lubricating properties of the uniformly dispersed and undamaged CNT in the flake powder
metallurgy method.