Breaking Behavior of Oxide Scale on the LPPS Bond Coats Surface During Pre-treatment in Vacuum

The small splashed particles on the low pressure plasma spray (LPPS) bond coats surface are often weakly bonded to the underlying coating surface, which have detrimental effect on the growth of the thermally grown oxide (TGO) and thereby TBCs lifetime. Results show that vacuum pre-treatment can make the splashed particles well bonded to the underlying coating surface through the element diffusion. However, it requires a successful breaking of the oxide scale during the pre-treatment. In this study, a three dimensional model was developed to explore the essential condition for the scale breaking. Moreover, some experiments were taken to verify the model and computation. This research can provide reference for the preparation optimization and pre-treatment optimization of bond coats towards high performance TBCs.