Failure of a continuous fiber ceramic composite after exposure to combustion ambients

A forensic investigation was performed to understand the failure of a continuous fiber ceramic composite tube used in a slot-forge furnace. The failure study consisted of visual inspections of both failed shards and as-received samples taken from a section removed before the tube was placed in service. Semi-quantitative SEM, X-ray diffraction, and microstructural analyses were also performed to determine the nature of glazing observed on the surface of the failed tube. Based on this analysis, the failure was apparently caused by oxidation and an eventual "burn-through and collapse" that was most likely precipitated by significant temperature excursions in excess of 1427 °C.