Effect of Ag on Tribological Properties of Bi_1.6Pb_0.4Sr₂Ca₂Cu₃O_x Superconducting Materials

Superconducting composites Ag/Bi1.6Pb0.4Sr2Ca2Cu3Ox with different contents of silver were successfully synthesized by high-temperature solid-state reaction method.The microstructure and phase composition of the as-synthesized samples were characterized by XRD and SEM.The tribological properties from ultra-low temperature to room temperature of the materials were studied by pin-on-disk friction testing.The results indicate that Ag/Bi1.6Pb0.4Sr2Ca2Cu3Ox materials were composed of superconductor phase and Ag phase.The friction coefficient of the samples decreased obviously when the temperature was lowered to less than the superconducting transition temperature.The friction coefficient was 0.4 in non-superconducting state.At superconducting transition temperature,the friction coefficient was 0.2.The friction coefficient of the material with addition of Ag increased with the increase of load and sliding speed.The influence law of Ag content on the friction coefficient was not significant.The properties of antifriction and wear resistance were improved after Ag addition.