Tribological behaviors of nanotwinned Al alloys

Wear-induced damages cause significant materials loss each year. Al alloys are widely used by industry but usually have low wear resistance. Here, we compare the tribological behaviors of ultrafine grained Al, a nano -precipitate hardened Al 7075 alloy and nanotwinned Al-Ni alloys using the nanoscratch. The nanotwinned Al-Ni alloys exhibit lower coefficient of friction and much greater wear resistance than the Al and Al 7075 alloys. The enhanced wear properties of Al-Ni alloys arise from their high strength and the evolution of nanotwinned mi-crostructures into gradient nanograins during wear. These findings on fundamental wear mechanisms in nano -twinned alloys may advance the discovery of wear-resistant metallic materials.