Sintering behavior of columnar thermal barrier coatings deposited by axial suspension plasma spraying (SPS)

Coatings with Columnar Microstructures for Thermal Barrier Applications

“…At first, the stability of the microstructure during thermal treatment has been investigated. [46] As expected, sintering takes place and leads to an increase in Young's modulus and fracture toughness within the columns. Important for the application is that the column gaps are not closed but even further opened due to the sintering.…”

Toward Ceramic Anticorrosion Coatings: A Review

“…Therefore, the combination of substrate surface roughness control and appropriate coating growth rate is the key to producing dense columnar structures. Zhou, et al, 31 prepared columnar SPS TBCs and studied the microstructure and mechanical properties of TBCs as a function of annealing time (1 h, 3 h, 10 h, and 50 h). They found that sintering results in the propagation of vertical cracks/pillar gaps and a decrease in porosity within the pillars.…”

Suspension Plasma Spray Thermal Barrier Coating Systems - Modelling and Performance Characterization Under Isothermal and Cyclic Oxidation Conditions

“…As shown in Figure 0 the splats, pore reduction and the healing of micro-cracks [117,14]. On the other hand, the decrease of E* and H could be induced by the formation and propagation of macro-cracks induced by the thermal stress [117,80].…”

“…[113], both surface and grain boundary diffusion were activated at 1100°C in plasma sprayed 7YSZ, resulting in reduction of intralamellar cracks and interlamellar pores. In addition, grain boundary diffusion can also lead to pores coarsening due to the volume change [14].…”

“…The performance of TBC systems at high temperatures is influenced by many factors, such as: i) TC degradation due to sintering and zirconia phase transformation [7,8], ii) thermal expansion mismatch between the layers, iii) Al depletion within the BC [9], iv) TGO growth stress [10], v) crack initiation and delamination [11], and others. Among these factors, sintering of YSZ leads to microstructure densification and phase decomposition resulting in subsequent changes of elastic modulus, hardness, and fracture toughness [12,13,14]. These changes have the likelihood to accelerate the cracking in the YSZ TCs, resulting in shorter YSZ TC lifetimes.…”