Abstract:
The superconducting material YBa
2Cu
3O
7-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 YBa
2Cu
3O
7-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 YBa
2Cu
3O
7-δ. The measurements prove directly the effect of electronic excitation on friction. Moreover,PbO/YBa
2Cu
3O
7-δ composite samples were prepared by sintering YBa
2Cu
3O
7-δ with PbO at different mass fractions to improve the tribological properties of YBa
2Cu
3O
7-δ at room temperature. The experimental results show that the friction coefficient of 15%PbO/YBa
2Cu
3O
7-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/YBa
2Cu
3O
7-δ is not degenerated. Finally,the anti-friction and anti-wear mechanism of PbO/YBa
2Cu
3O
7-δ is discussed.