Abstract: Oil leakage occurred after the engine served for one renovation period and extra 167 hours.It was found that the graphite ring separated from the metal shell and the surface color of the structural adhesive and the impeller changed.The appearance of the failed graphite seal ring and the impeller was inspected,and the metallographic structure of the graphite seal ring was analyzed.Shear strength test and high-temperature aging test were carried out for J-27H structural adhesive.The results indicate that the shedding-off of the graphite ring is due to the high temperature failure of J-27H epoxy structural adhesive resulting from friction heating,and has nothing to do with the property of the graphite seal ring and the structural adhesive.