Microstructural, mechanical and thermal properties of Al2O3/CYSZ functionally graded thermal barrier coatings

Kırbıyık F., Gok M. G., Göller G.

SURFACE & COATINGS TECHNOLOGY, vol.329, pp.193-201, 2017 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 329
  • Publication Date: 2017
  • Doi Number: 10.1016/j.surfcoat.2017.08.025
  • Journal Name: SURFACE & COATINGS TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.193-201
  • Keywords: Al2O3, CYSZ, Thermal barrier coating, Functionally graded, Thermal properties, PERFORMANCE, OXIDATION, BEHAVIOR, CONDUCTIVITY, SYSTEM, LAYER, TBCS, TEMPERATURE, COMPOSITES, RESISTANCE
  • Istanbul Technical University Affiliated: Yes

Abstract

In this study, CYSZ/Al2O3 ceramic TBCs were produced in double layered and FGed design having 4, 8 and 12 layers by high-velocity oxy-fuel and atmospheric plasma spraying processes. Microstructural, mechanical and thermal properties of the TBCs were evaluated. The thickness of metallic bonding layer and ceramic top coat were measured as 100 30 pm and 250 80 gm, respectively. Thermal conductivity value of the coating having 8 layered CYSZ/Al2O3 functionally graded design (0.82 W/m.K) were lowest compared to CYSZ/Al2O3 double layered (1.32 W/m.K) and CYSZ single layered (1.44 W/m.K) designs at 835 degrees C. Thermal cycle performance and bonding strength of the CYSZ/Al2O3 FGed TBCs were superior to those of single layered CYSZ and double layered CYSZ/Al2O3 coatings. Phase transformation from gamma-Al2O3 to alpha-Al2O3 was observed after the thermal cycle test. (C) 2017 Elsevier B.V. All rights reserved.