Microstructures and properties of thermal barrier coatings deposited by hybrid water-stabilized plasma torch

• Hybrid Water-Stabilized Plasma (WSP-H) torch provides high-enthalpy plasma which may be utilized for high-throughput and yet economical spraying of coatings from powders, suspensions, and solutions. It was previously demonstrated that microstructures and functional properties of the WSP-H coatings may be tailored to a wide extent for various new applications, namely those requiring high coating thickness and/or coating of large components. In this study, applicability of WSP-H technology for spraying of novel thermal barrier coatings (TBCs) is demonstrated. WSP-H technology was used for spraying of yttria-stabilized zirconia (YSZ) top-coats from powder, suspension and solution. Yttria content in the top-coat feedstock was 7-8 wt.%. NiCrAlY bond-coat was also sprayed by WSP-H and Hastelloy-X alloy was used as substrate material. Microstructure, phase composition, and endurance of the deposited coatings in thermal cycling fatigue (TCF) test were evaluated. Each thermal cycle consisted of rapid heating to 1100 °C, followed by one hour dwell and rapid cooling. All coatings showed excellent stability and TCF resistance withstanding more than 700 cycles surpassing in TCF test some of the currently commercially used TBCs. Lifetime of TBC with columnar top-coat deposited from suspension exceeded even more than 900 cycles. © 2019 ASM International. All rights reserved.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Materialteknik -- Bearbetnings-, yt- och fogningsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering -- Manufacturing, Surface and Joining Technology (hsv//eng)

Keyword

Microstructure; Sustainable development; Thermal cycling; Thermal fatigue; Thermal spraying; Thickness measurement; Waterworks; Yttria stabilized zirconia; Yttrium oxide; Zirconia

Deposited coatings; Functional properties; Hastelloy x alloys; Microstructures and properties; Substrate material; Thermal barrier coating (TBCs); Water stabilized plasmas; Yttria-stabilized zirconias (YSZ)

Thermal barrier coatings

Manufacturing and materials engineering

Produktions- och materialteknik

Production Technology

Produktionsteknik

Publication and Content Type

ref (subject category)

kon (subject category)