The thermal stability and failure mechanism of thick thermal barrier coatings(TBCs) with and without vertical type cracks were investigated through the cyclic thermal exposure and thermal-shock tests. The TBC systems ...The thermal stability and failure mechanism of thick thermal barrier coatings(TBCs) with and without vertical type cracks were investigated through the cyclic thermal exposure and thermal-shock tests. The TBC systems with thickness of about 2000 μm in the top coat were prepared by an air plasma spray(APS) on the bond coat of about 150 μm in thickness prepared by APS. The adhesive strength values of the as-prepared TBCs with and without vertical type cracks were determined to be 24.7 and 11.0 MPa, respectively, indicating the better interface stability in the TBC with vertical type cracks. The TBC with vertical type cracks shows a better thermal durability than that without vertical type cracks in the thermal cyclic exposure and thermal-shock tests. The hardness values of the as-prepared TBCs with and without vertical type cracks were found to be 6.6 and 5.3 GPa, respectively, which were increased to 9.5 and 5.5 GPa, respectively, after the cyclic thermal exposure tests. These results indicate that the vertical type cracks developed in the top coat are important in improving the lifetime performance of thick TBC in high temperature environment.展开更多
基金Project(2011-0030058) supported by the National Research Foundation of Korea(NRF) Funded by the Korean Government(MSIP)Project(20134030200220) supported by the Human Resources Development Program of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)Funded by the Korea Government Ministry of Trade,Industry and Energy and by the Korea Institute of Materials Science(KIMS) in 2013
文摘The thermal stability and failure mechanism of thick thermal barrier coatings(TBCs) with and without vertical type cracks were investigated through the cyclic thermal exposure and thermal-shock tests. The TBC systems with thickness of about 2000 μm in the top coat were prepared by an air plasma spray(APS) on the bond coat of about 150 μm in thickness prepared by APS. The adhesive strength values of the as-prepared TBCs with and without vertical type cracks were determined to be 24.7 and 11.0 MPa, respectively, indicating the better interface stability in the TBC with vertical type cracks. The TBC with vertical type cracks shows a better thermal durability than that without vertical type cracks in the thermal cyclic exposure and thermal-shock tests. The hardness values of the as-prepared TBCs with and without vertical type cracks were found to be 6.6 and 5.3 GPa, respectively, which were increased to 9.5 and 5.5 GPa, respectively, after the cyclic thermal exposure tests. These results indicate that the vertical type cracks developed in the top coat are important in improving the lifetime performance of thick TBC in high temperature environment.
