Study On Preparation And Tribological Properties Of Self-lubricating Metallic Plastic Composites

Self-lubricating metallic plastic composites is a new type of self-lubricating composite with steel backing- modified polytetrafluoroethylene, which mechanical properties are decided by the parent metal, and self-lubricating properties are decided by the surface plastic layer. It still has the outstanding tribology properties under oil-less lubrication or lubrication difficult conditions. Therefore, the self-lubricating metallic plastic composite has been widely used. The objective of this paper is to prepare a new type self-lubricating metallic plastic composites and study on its tribological properties, which can be easily applied in the tribological field. The mainly research contents and results as follow:First of all, through establishing the friction contact model, the relationship between friction coefficient and related parameters was derived. Meanwhile the formation mechanism of plastic transfer film and the effect of transfer film on the tribological properties were analyzed. Based on these, it was found that metallic plastic composite had notable tribological properties.Secondly, by analyzing material nature used in the experiments and preparation technology of metallic plastic composites, self-lubricating metallic plastic composites was prepared by the static electricity spraying and thermo- compression formation. The orthogonal optimization experiment discovered that the binding force was mainly influenced by polyphenylene sulfide in the medium plastic layer and copper oxide in the surface layer, and obtains best proportions when the binding force is biggest.Last but not least, using the UMT-2 multi-function friction and wear tester and corresponding equipments, the effects of surface plastic layer filler polyphenylene sulfide, applied load, sliding speed and lubrication conditions on tribological properties of self-lubricating metallic plastic composites were systematically investigated.The results show that self-lubricating metallic plastic composite had higher friction coefficient and ant-wear properties with the increase of filler polyphenylene sulfide content, and wear mechanism of composites transformed from micro cutting and adhesive wear to fatigue wear. Under the conditions of a certain range (15-25wt%) of the filler polyphenylene sulfide content in surface layer, self- lubrication metallic plastic composite had excellent tribological properties. Self-lubricating metallic plastic composite (filler polyphenylene sulfide content 15wt %) had lower friction coefficient with the increase of the applied load; had higher friction coefficient with the increase of the sliding speed. The self-lubricating metallic plastic composite had the cooperative effect with the lubrication oil under oil-lubricated condition, and had better tribological properties than under dry sliding condition.