超导PbO/YBa2Cu3O7-δ复合氧化物摩擦磨损性能

为适应从低温到高温宽温范围的使用条件,用溶胶-凝胶法制备了YBa₂Cu₃O_7-δ超导材料,用摩擦磨损试验机测试了YBa₂Cu₃O_7-δ从室温至液氮温度的摩擦学性能。结果表明：室温20℃下,YBa₂Cu₃O_7-δ与对偶件不锈钢盘对摩时,摩擦因数在0.5左右,当温度降到超导转变温度以下时（液氮温度-196℃）摩擦因数大幅度降低,YBa₂Cu₃O_7-δ超导态摩擦因数是正常态值的一半,实验直接证明了电子激励对摩擦能量耗散的作用。为改善室温下YBa₂Cu₃O_7-δ摩擦学性能, 掺杂不同质量分数PbO作为润滑组元,制备了PbO/YBa₂Cu₃O_7-δ超导固体润滑复合材料,取得良好效果。PbO掺杂不影响PbO/YBa₂Cu₃O_7-δ复合材料的超导电性,在正常的载荷和滑行速度下15%PbO/YBa₂Cu₃O_7-δ复合材料摩擦因数为0.2至0.3,磨损率为4.35×10-4 mm3·（N·m）-1,分析了PbO/ YBa₂Cu₃O_7-δ复合材料减摩耐磨机制。

Friction and wear behavior of the superconducting compound oxide of PbO/YBa2Cu3O7-δ

The superconducting material YBa2Cu3O7-δ samples were prepared by the sol-gel method. The tribological properties were measured on a friction and wear tester from ambient temperature to liquid nitrogen temperature. The results indicate that the friction coefficient of YBa2Cu3O7-δ against steeliness is about 0.5 at ambient temperature and decreases abruptly to half of the normal state value when the temperature is below the superconducting transition temperature of the YBa2Cu3O7-δ. The measurements prove directly the effect of electronic excitation on friction. Moreover,PbO/YBa2Cu3O7-δ composite samples were prepared by sintering YBa2Cu3O7-δ with PbO at different mass fractions to improve the tribological properties of YBa2Cu3O7-δ at room temperature. The experimental results show that the friction coefficient of 15%PbO/YBa2Cu3O7-δ is about 0.2~0.3 and the wear rate is 4.35×10-4 mm3·（N·m）-1,and the superconductivity of 15% PbO/YBa2Cu3O7-δ is not degenerated. Finally,the anti-friction and anti-wear mechanism of PbO/YBa2Cu3O7-δ is discussed.