Tailoring microstructure of double-layered thermal barrier coatings deposited by suspension plasma spray for enhanced durability
| Autor: | Satyapal Mahade, Adwait Rajeev Jahagirdar, Xin-Hai Li, Nicolaie Markocsan, Björn Kjellman, Stefan Björklund |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Sintering Surfaces and Interfaces General Chemistry Temperature cycling Fracture toughness Condensed Matter Physics Thermal diffusivity Microstructure Laser flash analysis Surfaces Coatings and Films Thermal barrier coating Materials Chemistry Suspension plasma spray Manufacturing Surface and Joining Technology Composite material Burner rig test Double layered Gadolinium zirconate Layer microstructures Suspension plasma sprays Test condition Thermal cyclic fatigue Thermal cyclic tests Top layers Yttria-stabilized-zirconia Bearbetnings- yt- och fogningsteknik Yttria-stabilized zirconia Durability Fatigue of materials Plasma spraying Thermal barrier coatings Thermal conductivity Yttria stabilized zirconia Yttrium oxide |
| Popis: | Gadolinium zirconate (GZ)-based TBCs comprising GZ as the top layer and yttria stabilized zirconia (YSZ) as the base layer, are attractive double-layered thermal barrier coatings (TBCs) for high temperature gas turbine engine application. This work attempts to understand the influence of individual layer microstructure on the durability of GZ/YSZ double-layered TBCs processed by suspension plasma spray (SPS). Two different spray parameters were chosen to obtain a combination of three microstructurally distinct GZ/YSZ double-layered TBCs i.e. GZ porous (P)/YSZ porous (P), GZ dense (D)/YSZ porous (P) and GZ dense (D)/YSZ dense (D). Thermal diffusivity of the as-deposited coatings was measured using Laser Flash Analysis (LFA) technique and the thermal conductivity of the TBCs was calculated. The GZ/YSZ double-layered TBC specimens were subjected to two different durability tests, i.e. thermal cyclic fatigue (TCF) and burner rig test (BRT). Sintering behavior of the individual layer TBC microstructures was evaluated by comparing the porosity evolution in as-deposited and TCF tested TBCs. Fracture toughness measurements performed on each layer of the double-layered TBCs were correlated with the durability results. Thermal cycling results amply demonstrate that the individual layer microstructure of GZ/YSZ double-layered TBC influenced its durability. Detailed failure analysis of the TCF and BRT failed specimens revealed similar failure modes for GZ (P)/YSZ (P), GZ (D)/YSZ (P) and GZ (D/YSZ (D) TBCs under identical thermal cyclic test conditions. However, failure modes differed when subjected to different thermal cyclic test conditions (TCF and BRT) and the probable causes are discussed. Findings from this work provide key insights on designing durable GZ/YSZ double-layered TBCs. The authors extend their thanks to Mr. Andreas Ottosson from GKN Aerospace AB, Sweden, for performing the burner rig test. |
| Databáze: | OpenAIRE |
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