Electrodeposition of Copper-Tin-Ptfe composite coatings

The aim of this research is to obtain lubricant composite coatings of bronze (90% copper and 10% Tin) with PTFE (polytetrafluoroethylene particles over mild steel substrate. The electrodeposition was carried out from an alkaline bath containing cyanide. The composite coatings were prepared hy means of CECD (Conventional Electrochemical deposition) and SCD (Sediment Codeposition) techniques. The PTFE particles involved were of the average size of 3-5 pm. The incorporation of PTFE in the composite coatings was investigated with respect to the PTFE concentration in bath, cathode current density. and mode of deposition. The cathode efficiency of the coating was calculated. The morphology of the eleetrodeposited c.omposites was studied using Scanning Electron Microscope (SEM) The PTFE distributions in the composite coatings are uniform at low concentration of PTFE in the bath but at high concentration the PTFE particles were agglomerated. The PTFE incorporation in SCD technique is higher than that of CECD technique. Physical properties of the composites including hardness, wear resistance and coefficient of friction, were measured