Influence of mechanical properties on thermal shock resistance of TBCs

Abstract

In this study, thermal barrier coatings with different porosities were prepared using 8 wt-% yttria-stabilized zirconia by atmospheric plasma spray on a superalloy substrate. The porosity of the ceramic coating was increased by modulating the primary gas flow rate and the secondary gas flow rate. The elastic modulus and fracture toughness of the coatings were measured by the indentation method, and the thermal shock resistance was evaluated by quenching the samples from 1050°C to room temperature. The Vickers hardness and elastic modulus of the coating were decreased by increasing the volume of the pores, and the fracture toughness was enhanced. It was found that the thermal shock resistance was improved owing to the stress release due to the pores.

Comparison of erosion rate of EB-PVD and plasma sprayed TBC

“…It is caused by the impact of large particles travelling at low velocities or smaller particles at higher velocities on the coating. This damage is characterized by significant deformation of the coating and this can sometime penetrate into the substrate and is accompanied by gross plasticity, deformation of the columns, shear bands and extensive cracking of the ceramic coating [6,22,26]. This mode, however, was not noted in present investigation.…”

Processing and Advancements in the Development of Thermal Barrier Coatings: A Review

“…The YSZ-based coating material manages residual tension from the base material's coated form [22]. This kind of residual stress is made from a couple of parts in that sprayed method, such as quenched stress that produces reduction for the various splats and cooled pressure generated by the unmatched heat extension between that deposited on the base material while all collectively cooled later deposited [23]. One of the promising ultra-hightemperature applicant metals for a material bond coat is the intermetallic composite NiAl, which has a higher molten point (1638 • C), lower density (5.9 g/cm 3 ), relatively greater elastic modulus (240 GPa), and excellent oxidation protection at 1200 • C [24].…”