Finite Element Analysis of Residual Stress in NiCrAlY/Yttria-Stabilized Zirconia Coatings by Nanoscale Multi-Layered Deposition

Abstract

In this paper, thermal residual stresses in multi-layered and compositionally graded NiCrAlY/yttria-stabilized zirconia coatings are analyzed by finite element method. These coatings are fabricated by detonation gun spraying using mechanically alloyed, plasma-spheroidized composite powders. The residual stresses of the as-sprayed coatings with different graded layers and different thickness, as well as the variations of residual stresses during thermal cycling are simulated by finite element analysis. The problems in design of compositionally graded materials are outlined and their modeling approaches are reviewed. Results showed that graded coating was more stable on the mechanical properties than normal duplex composites. And, the maximum compressive radial stress is found to be at or near the surface of the specimen where surface cracking may be generated.

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