Crack propagation in NiCoCrAl/YSZ multilayer film produced by EB-PVD in crack arrester orientation

3rd International Conference on New Material and Chemical Industry

材料科学;化学工业

Shi, G.D.^1 ; Wang, H.L.^1 ; Wu, Z.J.^1 ; Wang, J.H.^1

School of Aeronautics and Astronautics, State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian

116024, China^1

关键词: Columnar structures;    Crack deflections;    Crack-growth resistance;    Electron beam-physical vapor deposition;    High resistance;    Interface toughness;    Layer interfaces;    Surface notches;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/479/1/012071/pdf
DOI  :  10.1088/1757-899X/479/1/012071

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

A multilayer film containing 10 NiCoCrAl layers with thickness of about 35 μm and 9 ZrO2-Y2O3 (YSZ) layers with thickness of about 1 μm was fabricated by electron beam physical vapor deposition (EB-PVD). Considering the difficulty to machine a surface notch in the thin film, a 6 μm 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.