Strong, tough and high temperature self-lubricated fibrous monolithic ceramic in Al2O3/Cr2O3 system

A fibrous monolithic ceramic was constructed with Al 2 O 3 fiber cells surrounded by Cr 2 O 3 phase-two kinds of brittle ceramics, to achieve an excellent combination of high strength and toughness, which is usually mutually exclusive in engineering materials . The material was demonstrated to fail in a non-brittle fracture manner and showed a typical rising R-curve behavior with the maximum crack growth toughness of 9.05 MPa m 1/2 . Meanwhile, the composite ceramic exhibited excellent tribological performance at high temperatures, with the lowest friction coefficient of 0.29 and wear rate of 1.07 × 10 −5 mm 3 /Nm at 600 °C. It was also demonstrated that the thermal stability of Cr 2 O 3 has a great influence on the wear mechanism when the temperature was above 800 °C.