Numerical investigation of residual stresses in high temperature ZrO2 insulation coatings on Ag tape substrate for magnet technologies


ARMAN Y., ÖZGÜL M., Celik E.

JOURNAL OF THE AUSTRALIAN CERAMIC SOCIETY, vol.53, no.2, pp.855-861, 2017 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 53 Issue: 2
  • Publication Date: 2017
  • Doi Number: 10.1007/s41779-017-0099-6
  • Journal Name: JOURNAL OF THE AUSTRALIAN CERAMIC SOCIETY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.855-861
  • Keywords: Insulation, ZrO2, Sol-gel, Thermal stress, Lamination theory, Finite element method, FINITE-ELEMENT-METHOD, ELECTRICAL-PROPERTIES, SUPERCONDUCTING TAPES, CONDUCTORS
  • Dokuz Eylül University Affiliated: Yes

Abstract

In this research, the numerical investigation of residual stresses was carried out in high temperature ZrO2 insulation coatings on Ag tape substrate for magnet technologies. ZrO2 coatings were fabricated on Ag substrate using a reel-toreel sol-gel system. The microstructural observation of ZrO2 coatings was performed through an environmental scanning electron microscope (ESEM). ESEM micrograph revealed that ZrO2 coatings with crack had mosaic structure which is suitable for high temperature insulation fields. The thermal stresses in the each layer were determined by the means of the lamination theory for both elastic solution and the finite element method (FEM) for elastoplastic solution in the temperature range of 298 to 50 K in liquid helium. The residual stresses happened throughout the production are neglected because of gradually cooling process. As a result of this, all of the residual stresses at the 298 K are accepted to be zero. Difference of thermal expansion coefficients and elasticity modulus cause the thermal stresses in the layers.