Influence of isothermal and cyclic heat treatments on the adhesion of plasma sprayed thermal barrier coatings

• Published in: Surface & coatings technology Vol. 205; no. 23; pp. 5422 - 5429
• Main Authors: Eriksson, Robert, Brodin, Håkan, Johansson, Sten, Östergren, Lars, Li, Xin-Hai
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2011; Elsevier
• Subjects: Adhesion; Adhesion tests; Adhesive bonding; Applied sciences; Burner rig test; Coating; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fatigue (materials); Heat treatment; Materials science; Metals. Metallurgy; Nickel base alloys; Nonmetallic coatings; Physics; Production techniques; Superalloys; Surface treatment; Surface treatments; TBC; TECHNOLOGY; TEKNIKVETENSKAP; Thermal barrier coating; Thermal barrier coatings; Thermal cycling; Thermal cycling fatigue; Thermal shock; Yttria stabilized zirconia; Zirconium dioxide; TBC; Adhesion; Thermal cycling fatigue; Thermal shock; Thermal barrier coating; Burner rig test; Plasma; Spray coatings; Hot spraying; Thermal cycle; Surface treatments; Thermal fatigue; Non metal coating; Heat treatments; Thermal barriers; Plasma arc spraying
• ISSN: 0257-8972; 1879-3347; 1879-3347
• DOI: 10.1016/j.surfcoat.2011.06.007

The adhesion of thermal barrier coatings (TBC) has been studied using the standard method described in ASTM C633, which makes use of a tensile test machine to measure the adhesion. The studied specimens consist of air plasma sprayed (APS) TBC deposited on disc-shaped substrates of Ni-base alloy Hastelloy X. The bond coat (BC) is of a NiCoCrAlY type and the top coat (TC) consists of yttria-stabilised-zirconia. Before the adhesion test, the specimens were subjected to three different heat treatments: 1) isothermal oxidation at 1100 °C up to 290 h, 2) thermal cycling fatigue (TCF) at 1100 °C up to 300 cycles and 3) thermal shock at ~ 1140 °C BC/TC interface temperature up to 1150 cycles. The adhesion of the specimens is reported and accompanied by a microstructural study of the BC and the thermally grown oxides (TGO), as well as a discussion on the influence of BC/TC interfacial damage on adhesion properties of TBC. The adhesion was found to vary with heat treatment, as well as with heat treatment length. ► Adhesion tests for isothermally and cyclically heat treated thermal barrier coatings. ► Comparison between thermal cycling fatigue and burner rig test. ► No change in adhesion for isothermal heat treatment. ► Cyclic heat treatment gave lower adhesion.