Tailoring columnar microstructure of axial suspension plasma sprayed TBCs for superior thermal shock performance

• This paper investigates the thermal shock behavior of thermal barrier coatings (TBCs) produced by axial suspension plasma spraying (ASPS). TBCs with different columnar microstructures were subjected to cyclic thermal shock testing in a burner rig. Failure analysis of these TBCs revealed a clear relationship between lifetime and porosity. However, tailoring the microstructure of these TBCs for enhanced durability is challenging due to their inherently wide pore size distribution (ranging from few nanometers up to few tens of micrometers). This study reveals that pores with different length scales play varying roles in influencing TBC durability. Fracture toughness shows a strong correlation with the lifetime of various ASPS TBCs and is found to be the prominent life determining factor. Based on the results, an understanding-based design philosophy for tailoring of the columnar microstructure of ASPS TBCs for enhanced durability under cyclic thermal shock loading is proposed. © 2018 The Authors

Ämnesord

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

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

Nyckelord

Coatings; Durability; Fracture toughness; Microstructure; Plasma jets; Plasma spraying; Pore size; Shock testing; Size distribution; Thermal shock; Thermal spraying

Columnar microstructures; Cyclic thermal shocks; Design philosophy; Different length scale; Strong correlation; Superior performance; Suspension plasma spraying; Thermal barrier coating (TBCs)

Thermal barrier coatings

Manufacturing and materials engineering

Produktions- och materialteknik

Publikations- och innehållstyp

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