Microstructure based modeling of residual stresses in WC-12Co sprayed coatings.

Research output: Contribution to journalArticle

Abstract

In this study, the residual stresses in a thermal-sprayed tungsten carbide-cobalt coating are numerically investigated after a plasma-spraying process and after a subsequent roller-burnishing process. The results from the simulations are compared to the first experimental results obtained by a classical hole-drilling method. First, effective material parameters are identified by a detailed microstructure FE model based on scanning electron microscope (SEM) images of the coating. Then, two types of simulations are performed with regard to thermally induced residual stresses as well as the rolling process. In the first model, the microstructural details like pores, interface, and surface roughness are modeled in detail based on light microscope (LM) images. In the second model, the coating and substrate are assumed to be ideal homogeneous, and the interface and surface to be as planar. Furthermore, two types of boundary conditions are investigated: (1), the periodic boundary conditions for the left and right faces, and, (2) when these faces are free. It is shown that, for large sample sizes, the results nearly coincide. The simulation results show increasing compressive residual stresses in thickness direction after the rolling process, which is in qualitative agreement with the experiment. A layer of tensile stresses is obtained at the surface in the simulation which could not be captured by the hole-drilling method. Furthermore, an investigation with homogeneous material behavior is performed in 3D.

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Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Mechanical Engineering
Original languageEnglish
Pages (from-to)96-107
JournalJournal of Thermal Spray Technology
Volume21
Publication statusPublished - 2012
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes