Microstructural characterization of GZ/CYSZ thermal barrier coatings after thermal shock and CMAS+hot corrosion test

Gok M. G., Göller G.

Journal of the European Ceramic Society, cilt.37, sa.6, ss.2501-2508, 2017 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 37 Sayı: 6
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1016/j.jeurceramsoc.2017.02.004
  • Dergi Adı: Journal of the European Ceramic Society
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.2501-2508
  • Anahtar Kelimeler: CMAS, Gd2Zr2O7, Hot corrosion, Thermal barrier coating, Thermal shock
  • Hakkari Üniversitesi Adresli: Evet

Özet

In this study, first, Gd2Zr2O7/ceria–yttria stabilized zirconia (GZ/CYSZ) TBCs having multilayered and functionally graded designs were subjected to thermal shock (TS) test. The GZ/CYSZ functionally graded coatings displayed better thermal shock resistance than multilayered and single layered Gd2Zr2O7 coatings. Second, single layered YSZ and functionally graded eight layered GZ/CYSZ coating (FG8) having superior TS life time were selected for CMAS + hot corrosion test. CMAS + hot corrosion tests were carried out in the same experiment at once. Furthermore, to generate a thermal gradient, specimens were cooled from the back surface of the substrate while heating from the top surface of the TBC by a CO2 laser beam. Microstructural characterizations showed that the reaction products were penetrated locally inside of the YSZ. On the other hand, a reaction layer having ∼6 μm thickness between CMAS and Gd2Zr2O7 was seen. This reaction layer inhibited to further penetration of the reaction products inside of the FG8.