Abstract: The porous anodic aluminum oxide (AAO) film on a pure aluminum substrate was prepared by a two-step anodization in a 0.3M oxalic acid solution and pore-enlargement treatment in the phosphoric acid aqueous solution at 50~C. The diameter of highly ordered pore on the AAO film was about 9Ohm, and the thickness of the AAO film was 31μm. The mineral oil was infiltrated in the ordered nanometer sized pores of AAO film on an aluminum substrate due to the capillarity effect. The friction coefficient was measured using a ball-on-disk tribotester. The tests were conducted at loads range from 490 to 2450mN and at sliding velocities between 0.1 and 0.5m·s^-1. Oil infiltration in porous AAO film modified friction and considerably improved the wear resistance. As compared to the porous AAO film, the oil-infiltrated specimen had low friction coefficient. With increasing the applied load and sliding velocity, the friction coefficient of the oil-infiltrated film decreased. It indicates that the oil-infiltrated AAO film produced a new way to modify the friction and wear of aluminum alloy.

Key words: friction coefficient, oil-infiltrated, AAO film