THE PORE-ENLARGEMENT AND SELF-LUBRICATION TREATMENT OF ANODIC OXIDE FILM OF ALUMINUM

The anodic oxide film of aluminum formed in oxalic acid solution has a porous structure. The influence of pore-enlargement treatment on the porous structure and tribological properties of the film was investiga ted. After the pore-enlargement treatment, a method of synthesizing Mo S2 in the pores was used to improve the tribological properties of the film. The mechanism of friction reduction of MoS2 synthesized in the pores of the film is also discussed. The results show that with the du ration of pore-enlargement treatment, the diameter of the pores and th e surface porosity of the film increase, and the hardness and wear res istance of the film decrease. The diameter of the pores and the surfac e porosity of the film increase to about 70 nm and 30%, respectively, the optimum values being obtained at 2 h, while the film still maintai ns its high hardness and good wear resistance. After self-lubricating treatment, the friction coefficient decreases from 0.87 to 0.65, and t he wear rate of the steel ball decreases obviously. Since no MoS2 tran sfer film is formed between the tribocouple faces, the lubricating eff ect of MoS2 synthesized in pores of the film is limited.