Nanomechanical behavior of yttria stabilized zirconia (YSZ) based thermal barrier coating

Microstructure Observation and Nanoindentation Size Effect Characterization for Micron-/Nano-Grain TBCs

“…Recently, a great deal of research with respect to the effect of microstructure on thermal properties such as thermal shock (oxidation) resistances [6][7][8]12,13] and thermal insulation [9,14], and mechanical properties such as hardness and modulus [5,[14][15][16][17][18][19][20][21][22] have been done. Wang et al found that the nanostructured zirconia coating possessed a better thermal shock resistance than that of the conventional zirconia coating [7].…”

“…Wu et al found that the reduction of porosity resulted in increase of thermal diffusivity, suggesting a significant degradation in the thermal barrier effect [14]. Some researchers have studied the effect of microstructure on hardness and modulus at high temperature [14][15][16][17][18]. They all discovered that the hardness and modulus of TBCs increased with the decrease of porosity caused by sintering of coating at high temperature.…”

“…They all discovered that the hardness and modulus of TBCs increased with the decrease of porosity caused by sintering of coating at high temperature. Nath et al evaluated the resistance to plastic deformation of TBC at room temperature and with thermal exposure [15]. Baiamonte et al indicated that nanostructured coating had larger hardness and modulus than the conventional coating by dynamic indentation tests at room and high temperatures [18].…”

“…In order to study the mechanical properties (hardness and modulus) of TBCs, several tests have been presented and widely used, such as beam bending tests [18,[23][24][25] and indentation tests [5,[14][15][16][17][18][19][20][21][22][23]26,27]. Thompson et al indicated that the modulus given by indentation test was much higher than the value based on the beam bending technique [23], which is consistent with Baiamonte reported [18], because indentation test gave an indication of local modulus, and beam bending test gave a global value which contained the effects of micro-crack and porosity.…”

Mechanical Properties of Double-Layer and Graded Composite Coatings of YSZ Obtained by Atmospheric Plasma Spraying

“…Nanoindentation technique has been succesfully used for characterisation of mechanical properties of plasma spray coatings because this technique allows to easily distinguish the melted and partially melted areas in the coatings and therefore to correlate these areas with mechanical properties by determining elastic modulus and/or hardness of different points throughout the coating cross-section [14,15]. Thus first part of the research previous works have shown that elastic modulus and hardness in titania or YSZ coatings can widely vary on the basis of the amount of partially melted areas present in the coatings while the porosity and sintering degree of these partially melted areas can also play a role [5].…”