Nanocomposite Lanthanum Zirconate Thermal Barrier Coating Deposited by Suspension Plasma Spray Process

Thermal conductivity and thermal cyclic fatigue of multilayered Gd2Zr2O7/YSZ thermal barrier coatings processed by suspension plasma spray

“…The preferable particle size of the feedstock used in APS ranges from 10-140 µm. It was found that with the use of nano sized powders, improvement in thermal shock resistance can be obtained due to the lower tensile stress in plane and higher fracture toughness of nanostructured layers [30][31][32]. However, feeding of powders below 10µm into a plasma jet is considered near impossible and agglomerated nano powders retain only a little of their original structure in the final coating [33][34].…”

Nanocomposite Coatings: Preparation, Characterization, Properties, and Applications

“…The spray material is a nanosized alloy powder (formed by ball milling [48]) and dispersed in a suspension solution using suspensions (Thermally Sprayed [47] and Suspension Plasma Spray Process [46]) to conduct plasma thermal spraying.…”

“…There are also several other methods for the elaboration of nanocomposite coatings but they are less popular such as the following: self-assembly (O/I coatings [46]); layer-by-layer assembly (O/O coatings [157]); localized laser heating, solid-state displacement reactions, ball impact deposition (for I/I coatings [158][159][160], resp. ); and atomic layer deposition (for I/O coatings [161][162][163]).…”

“…For inorganic matrix, such as metal matrix or alloy matrix, these nanocomposite coatings could be prepared by various methods, including chemical vapor deposition (CVD) (see Figure 3), powder metallurgy, physical vapor deposition (PVD) [41][42][43][44][45], thermal plasma spray [46][47][48], sol-gel [49][50][51][52] (see Figure 1), epitaxial growth [53], cold spray [54][55][56][57][58][59][60][61] (see Figure 2), and electrodeposition [62][63][64][65][66][67]. Metal matrix composite coatings that dispersed a second phase [68,69] have attracted extensive attention owing to unique properties such as oxidation and corrosion resistance [69,70], wear resistance [71,72], and magnetic properties [72].…”

“…In these coatings, one metal may be converted into nitride in the nanocrystalline phase and the other may be transported into the growing film unreacted. On the other hand, thermal posttreatment has strong effect not only on the grain size [50,59], crystallization [154], and morphology [168] but also on the dislocation density and the interactions between nanoparticles and the matrix [46] or the bonding of microstructural phases [47].…”