|
3646 |
|
Healing of the interface between splashing particles and underlying bulk coating and its influence on oxidation behavior of bond coat |
|
Guan-Jun Yang* / School of Materials Science and Engineering, Xi'an Jiaotong University, China Bang-Yan Zhang / State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, China Jing Shi/ State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, China Cheng-Xin Li/ State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, China Chang-Jiu Li/ State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, China |
|
The thermally grown oxide (TGO) formed on bond coat surface plays an important role in determining the lifetime of thermal barrier coatings (TBC). The splashing particles on the thermally sprayed bond coat surface are weakly bonded to the underlying bulk coating, which leads to the formation of mixed oxides and subsequently early failure of TBC. In this study, the healing behavior of the weakly bonded interface between splashing particles and underlying bulk coating deposited by low pressure plasma spraying was examined during vacuum annealing, and the influence of interface healing on the isothermal oxidation behavior of the bond coat was investigated. Results show that the granular particles resulting from splashing of molten droplets were adhered on smooth splats which make up the surface of bulk coating. After the vacuum heat treatment, the small granular splashing particles were aggregated to bulk coating resulting from the element diffusion at the interface between splashing particles and underlying bulk coating. As a result, the formation of mixed oxides was effectively restrained due to the healing of the splashing particle/underlying bulk coating interface. |