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论文类型：会议论文

发表时间：2019-01-01

收录刊物：CPCI-S、EI

卷号：479

期号：1

摘要：A multilayer film containing 10 NiCoCrAl layers with thickness of about 35 mu m and 9 ZrO2-Y2O3 (YSZ) layers with thickness of about 1 mu m was fabricated by electron beam physical vapor deposition (EB-PVD). Considering the difficulty to machine a surface notch in the thin film, a 6 mu m thick YSZ layer with the columnar structure was deposited as the outer layer of the multilayer film, which was used to introduce the initial crack tip normal to the film surface. The crack propagation in the crack arrester orientation was analyzed by in situ examining the effect of microstructure. The R-curve and the interface toughness for delamination were determined. It was found that crack propagated along the columnar boundaries in the YSZ layers with the negligible crack growth resistance and that a small part of NiCoCrAl columnar boundaries provided relatively low resistance to crack growth due to the intercolumnar pores. However, most of NiCoCrAl columnar boundaries provided relatively high resistance to crack growth. Moreover, the resistance to crack-growth increased with increasing crack-length. The crack deflection at the layer interfaces and the plastic deformation of NiCoCrAl layers were the important factors resulted in the increasing resistance.