Unveiling Ultra-High Temperature Wear and Indentation Damage Mechanisms of Thermal Barrier Coatings

Bumgardner, Clifton; Li, Xiaodong

doi:10.1007/s11837-015-1622-2

Cited by 5 publications

(1 citation statement)

References 23 publications

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“…Chen et al [18] presented an analytical model to study the influence of geometric parameters on fracture characteristic of coating system. Bumgardner et al [19] studied the wear and indentation damage mechanism of TBCs during its operational lifecycle, in which a coupled imaging and contact model analyses was adopted to identify the location and time of delamination and its underlying causes. Sun et al [20] investigated the initiation of interfacial cracks considering the creep of thermally grown oxide by theoretical and numerical analyses.…”

Section: Introductionmentioning

confidence: 99%

Competition mechanism of interfacial cracks in thermal barrier coating system

et al. 2017

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Abstract:The mechanism of competition between different interfacial cracks is investigated, specifically considering the cracks at top-coat/bond-coat and bond-coat/substrate interfaces in a thermal barrier coating system (TBCs). To assess the cracking process driven by mechanical loading, in-situ three-point bending tests were conducted on TBCs samples having different top coats (TC) and bond coats (BC). The competition between cracks at TC/BC and BC/substrate interfaces was observed for the first time, and then analyzed to elucidate the mechanism. Experimental and numerical results show that the differences in modulus ratio and thickness ratio of TC to BC are the main factors controlling the competition, which eventually leads to different fracture modes, i.e. when TC thickness is large or BC modulus is low, the coatings peel off from the TC/BC interface; while, with the decreasing TC thickness or increasing BC modulus, the delamination location changes to BC/substrate interface. A failure map based on the two ratios is numerically established, which agrees well with the experimental results. It is advised that the crack propagation path can be controlled by adjusting the combination of the two ratios to trigger both TC/BC and BC/substrate interfacial cracks in TBCs, thereby leading to more energy dissipation and better bending-resistance.

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Section: Introductionmentioning

confidence: 99%