Effects of supersonic fine particle bombarding on thermal cyclic failure lifetime of thermal barrier coating

CHEN Ya-jun^1,2, LIN Xiao-ping³, WANG Zhi-ping², WANG Li-jun¹, JI Zhao-hui², DONG Yun³

1.School of Materials Science and Engineering,Tianjin University,Tianjin 300072,China;2.Sino-European Institute of Aviation Engineering,Civil Aviation University of China,Tianjin 300300,China;3.School of Materials Science and Engineering,Northeastern University at Qinhuangdao,Qinhuangdao 066004,China



Abstract:

Thermal barrier coating ( TBC) consisting of a NiCoCrAlY bond coat ( BC) and a ZrO2-8 wt. % Y2O3 topcoat ( TC) was fabricated on the nickel-base superalloy by air plasma spray ( APS) . The BC was treated by supersonic fine particle bombarding ( SFPB) . Thermal cyclic failure and residual stress in thermally grown oxide ( TGO) scale were studied by SEM with EDS and ruby fluorescence spectroscopy ( RFS) . As shown in the results,after treated by SFPB,thickening of TGO was relatively slow,which reduced the level of growth stress. The TBC with SFPB treatment was still remained well undergoing 350 times of thermal cycle. However,after thermal cycle with the same times,the separation of TC was observed in TBC without SFPB treatment. The residual stress analysis by RFS showed that the residual stress of SFPB-treated TBC increased with the increasing number of thermal cycle. The residual stress of conventional TBC reached a value of 650 MPa at 350 times of cycle and that of SFPB-treated TBC only reached 532 MPa at 400 times of cycle. The BC with SFPB treatment after 400 times of cycle was analyzed by RFS,the high stress value was not observed in local thickened region of TGO. Thermal cycling resistance of TBC can be improved by the SFPB technology.

Key words:  supersonic fine particle bombarding  TGO  thermal cycles  residual stress  TBC

DOI£º10.11916/j.issn.1005-9113.2010.04.016

Clc Number:TG174.4

Fund: