Method of forming stabilized plasma-sprayed thermal barrier coatings

A method for stabilizing a porous thermal barrier coating plasma sprayed on a substrate, comprising the steps of:

• immersing the porous thermal barrier coating in a sol gel comprising a metal oxide or precursor thereof, a solvent, and a surfactant;
• applying vacuum pressure to the sol gel to infiltrate the porous thermal barrier coating with the sol gel;
• and
• drying the sol gel to produce discrete residual metal oxide particles in the porous thermal barrier coating.

A method for stabilizing a porous thermal barrier coating plasma sprayed on a substrate, comprising the steps of:

• immersing the porous thermal barrier coating in a non-aqueous sol gel comprising between 2 and 20% by weight of a metal oxide or precursor thereof, a solvent, and a surfactant;
• applying vacuum pressure to the sol gel to substantially infiltrate the entire porous thermal barrier coating with the sol gel;
• drying the sol gel to produce a non-uniform distribution of discrete residual metal oxide particles filling a minority of the volume inside the porous thermal barrier coating;
• and
• heating the porous thermal barrier coating to bond the metal oxide particles with the porous thermal barrier coating,
• wherein the metal oxide particles are dispersed in the pores through substantially all of the thermal barrier coating and in a discontinuous manner to provide no significant environmental protection to the thermal barrier coating.

A turbine engine component, comprising:

• a substrate;
• a plasma-sprayed thermal barrier coating formed over at least a portion of the substrate and having nanometer- and micron-sized pores throughout the entire thermal barrier coating;
• and
• discrete stabilizing particles dispersed in the pores through substantially all of the thermal barrier coating and in a discontinuous manner to provide no significant environmental protection to the thermal barrier coating.