کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1658954 | 1008364 | 2010 | 9 صفحه PDF | دانلود رایگان |
In this study, the adhesion strength of thermal barrier coatings 8YSZ (ZrO2 + 8 wt.% Y2O3) deposited on NiCrAlY bond coats by atmospheric plasma spraying is investigated experimentally. A modified four-point bending specimen that can generate a single interface crack to facilitate the control of crack growth was adopted for testing. The fracture surfaces were examined using a scanning electron microscope. Images show that cracks are initiated along YSZ/NiCrAlY interfaces, then kink and grow uniformly within the YSZ layer. The load–displacement curves obtained indicate three distinct stages in crack initiation and stable crack growth. Based on a microstructural model, finite element analyses were performed to extract the bonding strength of the thermal barrier coatings. The fracture toughness of the plasma-sprayed 8YSZ coatings, in terms of critical strain energy release rate Gc, can be reliably obtained from an analytical solution or from a numerical simulation of the cracking process using compliance methods.
Journal: Surface and Coatings Technology - Volume 204, Issue 24, 15 September 2010, Pages 4066–4074