Bending fatigue failure of atmospheric-plasma-sprayed CoNiCrAlY+YSZ thermal barrier coatings

Fatigue Crack Growth in Bodies with Thermally Sprayed Coating

“…The microfractographic features of the coating are extremely difficult to identify them due to the complicated coating microstructure (see Ref 6,16,28). All fatigue cracks propagated in a shape of a half or quarter ellipse with major axis situated at the substrate surface, justifying the approximation in Fig.…”

Stability of plasma-sprayed thermal barrier coatings: The role of the waviness of the bond coat and the thickness of the thermally grown oxide layer

“…For this to happen, separation having diameter of the order of 1 mm must develop around the interface [13] and, therefore, these cracks would have to interconnect over the distances on the order of hundreds of microns. Note also, that the stress state in the coating with such highly irregular non-periodic interface is rather complex [23], and consequently the locations where the delamination cracks will be initiated in real coatings are difficult to predict.…”

“…These parameters were varied in the range of 10-30 μm and 125-500 μm, respectively, corresponding to waviness of manufactured plasma-sprayed coatings, such as, for example, the one shown in Fig. 1, or those presented in micrographs in references [8,12,19,23]. Based on preliminary calculations, the thickness of the substrate, t S , was set to 25 mm so as to exclude its influence on the stress distribution in the coating.…”

Ce1−x Sm x O2−x/2—A novel type of ceramic material for thermal barrier coatings

“…Thermal barrier coatings (TBCs) are advanced material system which is always used to protect underlying metallic components in turbine engines from damage caused by corrosive hot gas or high temperature [1][2][3]. In the system of thermal barrier coatings, the ceramic top coat shields the underlying material from heat, and the metallic bond protects the substrate against high temperature degradation and improves adherence of the top coat [4].…”

“…In recent years, ceramic oxides with pyrochlore structure or defect fluorite structure have been widely studied [8][9][10][11]. Except for the A 2 B 2 O 7 -type (A = rare earth element, B = Zr, Ce, Hf, Sn) oxides [1][2][3][4][5][6][7][8][9][10], the cerium oxides with fluorite structure have recently attracted extensive attention due to a diversity of applications, such as conversion catalysts for selective hydrogenation of unsatured compounds, catalysts for three-way automobile exhaust systems, abrasives for chemical polishing slurries, gates for metal-oxide semiconductor devices, and luminescent materials for violet/blue fluorescence [12][13][14]. Now, the rare earth doped CeO 2 (RE 2 O 3 -CeO 2 ) have also been considered to be new materials for TBCs and solid oxide fuel cells due to the excellent electrical, mechanical, and thermophysical properties [15][16][17].…”