FATIGUE OF ALUMINA-CHROME CARBIDE COMPOSITE COATING

摘要

The fracture and fatigue characteristics of alumina coating strengthen with chrome carbide layer, is presented and discussed. The essential aspects of the methodology include acoustic emission monitoring of crack activity and its propagation under cyclic loads. Structural analysis of the alumina revealed an effect of α, γ phases of alumina and CrC thickness on fatigue life of the coating. The fatigue life of the coatings is found to be no longer than 10~3 cycles. None of the coatings resist above 10~3 cycles. It is found to be cracks initiation and propagation in the coating interface that result in the catastrophic failure of the composite. An ultimate load resulted in intensive crack growth in CrC-Al_2O_3-Al is found to be about 2 GPa that is higher than that in alumina coating.