Effects of Additive CeO_2 on Thermal Shock Resistance of Plasma Sprayed Cr_2O_3 Coating

The influence of CeO 2 with different content on the thermal shock resistance of plasma sprayed Cr 2O 3 coating was investigated. The thermal shock failure mechanism of coating was also studied. It is found that the thermal shock failure mechanism of coating is thermal stress fatigue destruction, and the destruction takes place at interface of ceramic and bond coating. The experimental results show that the lifetime of coating fracture and failure increase considerably when 3%CeO 2 is added into the plasma sprayed Cr 2O 3 coating. The suitable content of CeO 2 makes the microcracks exist in network form. The microcrack net can release internal stress in coating, delay the crack forming and expanding and decrease holes in coating. Thus the thermal shock resistance increase largely.