EB-PVD热障涂层对激光打孔孔径及热循环后孔径变化影响的研究

Investigation on Effect of EB-PVD Thermal Barrier Coatings on Diameters of Gaseous Envelope Cool and Thermal Circles

在试样上用激光打了不同孔径、不同方向的冷却孔 ,采用电子束物理气相沉积 (EB PVD)的方法在已打孔的试样上涂覆MCrAlY粘接层和ZrO2 陶瓷层 ,观察和计算其孔径大小变化 ;然后对试样进行了热循环处理 ,以比较热循环前后的孔径变化。初步实验结果表明 :激光打孔的入射角 ,对孔径变化影响不大 ;原始孔径增大 ,施以涂层后其相对变化就较小 ,采用EB PVD的方法在已打孔的试样上涂覆ZrO2 陶瓷层后其孔径比原始孔径至少减少了 15 % ;在热循环试验前后 ,绝大部分孔径变化较小 ,而其总趋势是由大变小 ,孔径减少约5

This paper emphasizes the effect of electron beam physical vapor deposition (EB PVD) thermal barrier coatings on the diameters of the punctures by laser punct uring.The specimens were initially punctured with different punctures in diamete r and direction by the laser puncturing method and then deposited with MCrAlY bo nd coat and ZrO 2 ceramic topcoat by means of EB PVD. Thereafter, the changes of the pores were evaluated.It is found that the angles of incidence of the por es have little influence on the diameters of the punctures. The bigger the origi nal 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 ZrO 2 ceramic topcoat were decreased by approximately 15% compared with t hose of the original punctures. The results show that the changes of punctures i n diameter can be ignored after 100 thermal circles.