Investigation on effect of EB-PVD thermal barrier coatings on diameters of gaseous envelope cool and thermal cycling

This paper emphasizes the effect of electron beam physical vapor deposition (EB-PVD) thermal barrier coatings on the diameters of the punctures by laser puncturing. The specimens were initially punctured with different punctures in diameter and direction by the laser puncturing method and then deposited with MCrAlY bond coat and ZrO₂ ceramic topcoat by means of EB-PVD. The changes of the pores were evaluated. It was found that the angles of incidence of the pores have little influence on the diameters of the punctures. The bigger the original punctures, the smaller the relative changes of punctures after being coated with thermal barrier coatings. The diameters of the punctures coated with the EB-PVD ZrO₂ ceramic topcoat are decreased by about 15% as compared with that of the original punctures. The results show that the changes of punctures in diameter can be ignored after 100 thermal cyclings.