FATIGUE OF A PORCELAIN CERAMIC UNDER REPEATED IMPACT LOADING

摘要

The failure of a porcelain ceramic as a result of repeated impact has beep studied. The study was conducted in an improved pendulum type repeated impact apparatus specially designed and fabricated for determining single and repeated impact strength. A definite fatigue behaviour has been demonstrated for specimens of a hard porcelain tested under air and liquid nitrogen with progressive endurance at lower stress regimes. Fractographic analysis showed the existence of mirror and hackle regions with a transgranular crack path near the fracture origin with progressive intergranular pattern in and around the hackle area Crack resistance caused by microcrack branching or crack-path deflection during impact loading has been suggested to explain the fatigue behaviour of the porcelain material tested.