Abstract:ulse electrodeposition was used to fabricate the CuSnPTFE composite coating in pyrophosphate electrolyte.The influences of current density,pulse frequency and duty cycle on the microstructure,composition,hardness and tribological behaviors of the composite coatings were studied.The results show that with the decreasing of the current density and pulse duty cycle,the composite coating surface becomes smooth and the microhardness is increased gradually;With the increasing of pulse frequency,the friction coefficient of the coating of the composite coatings tends to decrease.Higher fluorin (F) element content in the composite coating will lead to lower hardness of coating,while PTFE particles in the composite coating will make the coating have excellent self lubrication properties during friction process.The microstructure of composite coating is uniform with high PTFE content and excellent tribological performance,when the current density,frequency and duty cycle of combinational pulse parameters are 25 A/dm2,3 000 Hz and 60%,respectively.