Size-dependent interface adhesive energy and interface strength of nanostructured systems

Abstract

An analytical model about the size-dependent interface adhesive energy and the interface binding strength was developed based on the size-dependent surface energy and the interface cohesive zone model. The model predicts the enhanced interface binding strength between the nanostructured ceramic coatings and the bulk metallic substrates compared to that between the conventional ceramic coatings with micron-scale grains and the same substrates. The interface binding strength between the ceramic coatings and the metallic substrates was measured by the tensile adhesion test method. The result shows that the interface binding strength of the nanostructured coatings with grain diameter of average 70 nm increases by 86%. The experimental result is in agreement with the theoretical prediction.

Thickness-dependent fracture characteristics of ceramic coatings bonded on the alloy substrates

“…The thermal barrier coating samples used in this study consist of the YSZ (8 wt.% Y 2 O 3 stabilized ZrO 2 ) top coatings prepared by the standard atmospheric plasma spraying method [9,10], the NiCrAlY (25.42 wt.% Cr-5.1 wt.% Al-0.48 wt.% Y) bond coatings prepared by the high velocity oxygen fuel method, and the Ni-based superalloy substrates [10]. The detailed preparation process and the microstructure of the coatings can be referred to Ref.…”

Power-law characteristics of damage and failure of ceramic coating systems under three-point bending

“…The thermal barrier coating samples used in this study consist of YSZ (8 wt.% Y 2 O 3 stabilized ZrO 2 ) top coatings prepared by the standard atmospheric plasma spraying method [13][14], NiCrAlY (25.42wt%Cr-5.1wt%Al-0.48wt%Y) bond coatings prepared by the high velocity oxygen fuel method, and Ni-based superalloy substrates [14]. The detailed preparation process and the microstructure of the coatings were described in Ref.…”

“…The detailed preparation process and the microstructure of the coatings were described in Ref. [14]. We prepared thick coating samples with a coating thickness of 350-490 μm, and thin coating ones with a coating thickness of 150-200 μm.…”

“…For both the thin and thick coating samples, two kinds of ceramic coatings were prepared by the use of different raw powders. One kind of coating with grains of about 40-100 nm diameter prepared from nanostructured YSZ powder [14], is represented by Nx with x being the sample number. The other kind is a conventional coating with micrometer scale splat grains of 200 μm diameter and 2 μm thickness prepared from conventional YSZ powder [1,14] and is represented by Mx.…”

“…One kind of coating with grains of about 40-100 nm diameter prepared from nanostructured YSZ powder [14], is represented by Nx with x being the sample number. The other kind is a conventional coating with micrometer scale splat grains of 200 μm diameter and 2 μm thickness prepared from conventional YSZ powder [1,14] and is represented by Mx. A single number x denotes the thin coating samples, such as N0, M3…, and a double number x represents the thick coating samples, such as M00, N30, etc.…”