Mechanical and Tribological Properties of Ag/YBa₂Cu₃O_7-δ Self-lubricating Composites

Ag/YBa2Cu3O7-δ (YBCO) self-lubricating composites with uniform and compact structure were prepared by powder metallurgy method.The phase composition and microstructure was studied by XRD and SEM.The effects of Ag content on the microstructure evolution and related mechanical and tribological properties of the composites were studied.The results showed that at normal temperature and pressure,when Ag content was 10wt.%,the composite had the best tribological properties.With the increase of Ag content,hardness of the composties decreased and fracture toughness increased.Under vacuum condition,the friction coefficient of the composites reduced with the increase of Ag content,and didnt change with the sliding velocity.When the temperature was lowered to below superconducting transition temperature of the superconductor,the friction coefficient decreased sharply.