Tribological behaviour of the green anode paste with a steel plate at 150 °C

In order to accurately predict the mechanical behaviour of paste during forming process, the friction law between the carbon paste and the mould wall is an important parameter to be determined. This paper presents the tribological behaviour of the lubricated paste/steel interface subjected to high stress conditions at the anode forming temperature of 150 ℃. A method to characterize the tribological behaviour has been developed and an apparatus was built. The method is based on the comparison of two successive experiments. In the first experiment, the paste is in contact with the friction plate. In the second one, a layer of Teflon is placed under the paste in order to excite another parameter thereby allowing the identification of the friction coefficient between the paste and steel wall. These experiments were performed with a paste under different normal loads. The static and kinetic friction coefficients of the Teflon/steel, steel/steel and paste/steel interfaces have been estimated. The static and kinetic friction coefficients of the Teflon/steel are respectively 0.17 and 0.13. The steel/steel friction coefficients were evaluated twice which gave a static coefficient that varies between 0.22 and 0.30. The kinetic coefficient varies between 0.18 and 0.25. The static and kinetic paste/steel friction coefficients obtained from both experiments are clearly similar. Their values are 0.15 and 0.13 respectively.