Low thermal conductivity, high toughness TBC compositions
A composition is provided of a rare earth-doped zirconium oxide having a tetragonal structure and having a formula: Y a Ln b Ta x Nb z Zr 1-a-b-x-z O 2-δ where Ln is a rare earth element or a mixture of rare earth elements; 0≤a≤0.06; 0.06≤b≤0.12; 0≤x≤0.1; 0≤z≤0.1; 0.08≤(x+z)≤0.1; 0.16≤(a+b+x+z)≤0.22; and 0.01≤δ≤0.05. Methods of forming a coating with this composition, along with the coated components, are also provided.
1 . A composition comprising:
a rare earth-doped zirconium oxide having a tetragonal structure and having a formula
selected from the group consisting of:
Y 0.06 Sm 0.06 Ta 0.1 Zr 0.78 O 1.99 :
Y 0.06 Sm 0.06 Nb 0.1 Zr 0.78 O 1.99 ;
Y 0.03 Sm 0.09 Ta 0.1 Zr 0.78 O 1.99 ;
Y 0.03 Sm 0.09 Nb 0.1 Zr 0.78 O 1.99 ;
Y 0.03 Sm 0.06 Yb 0.03 Ta 0.1 Zr 0.78 O 1.99 ;
Y 0.03 Sm 0.06 Yb 0.03 Nb 0.1 Zr 0.78 O 1.99 ;
Sm 0.08 Yb 0.04 Ta 0.1 Zr 0.78 O 1.99 ;
Sm 0.12 Nb 0.1 Zr 0.78 O 1.99 ; and
mixtures thereof.
2 . The composition of claim 1 , wherein the composition has a thermal conductivity of 1.5 W/m-k to 1.8 W/m-k at 1000° C. as measured via a laser flash method according to ASTM E1461-13.
3 . A coated component, comprising:
a substrate having a surface; and
a thermal barrier coating on the surface, wherein the thermal barrier coating includes a layer comprising the composition of claim 1 .
4 . The coated component of claim 3 , further comprising:
a bond coat on the surface of the substrate and positioned between the surface of the substrate and the thermal barrier coating.
5 . The coated component of claim 4 , further comprising:
a barrier coating on the bond coat and positioned between the bond coat and the thermal barrier coating, wherein the barrier coating comprises yttria-stabilized zirconia.
6 . A method of forming a coated component, the method comprising:
applying a layer onto a surface of a substrate, wherein the layer includes the composition of claim 1 .