کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1660592 1008406 2009 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Thermal barrier coating systems — analysis of nanoindentation curves
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فناوری نانو (نانو تکنولوژی)
پیش نمایش صفحه اول مقاله
Thermal barrier coating systems — analysis of nanoindentation curves
چکیده انگلیسی

Mechanical properties (Young's modulus E, hardness H, degree of plasticity) of all three components of thermal barrier coatings systems, prepared by electron beam physical vapour deposition (EB PVD), have been investigated by nanoindentation. The power-law exponents n and m, describing the shapes of the loading and unloading nanoindentation curves, increase with peak load for the yttrium-stabilized zirconia top coat (TC), containing 4 mol% Y2O3, and the NiCoCrAlY bond coat (BC). The variations of m are correlated to the degree of plasticity. Decrease of the hardness with increasing peak load, generally known as indentation size effect (ISE), is observed only for the TC and the BC. The ISE in the TC is explained using a new empirical equation based on the concept of elastic recovery. The average Young's moduli of the Ni-based superalloy substrate, the BC and the TC are 189 ± 11 GPa, 166 ± 7 GPa, and 126 ± 25 GPa, respectively. The corresponding average hardness values are 3.3 ± 0.3 GPa, 5.5 ± 0.2 GPa, and 6.2 ± 1.7 GPa, respectively. The mechanical properties of the TC show complex behaviour upon annealing at 1000°°C in air, which can be explained by changes in the porosity and the residual stresses.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface and Coatings Technology - Volume 203, Issue 14, 15 April 2009, Pages 2064–2072
نویسندگان
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