Chemically complex ceramic abradable sealant materials
A chemically complex oxide powder is provided that forms an abradable sealant coating for a turbine engine. Primary property advantages of the chemically complex oxide include low resistance to erosion and reduced wear on blades and labyrinth seal knife edges in a turbine engine. Secondary property advantages include improved thermal properties, excellent sintering resistance, excellent phase stability, and high resistance to chemical attack.
1 . A thermal spray material feedstock, comprising:
a high entropy oxide (HEO) having calcia magnesia alumina silicate (CMAS) resistance,
wherein when the oxide is reacted at 1250° C. for 8 hours with a CMAS having a low melting temperature of 1110° C. to 1125° C., the oxide exhibits a CMAS penetration depth of 100 μm or less.
2 . The thermal spray material feedstock of claim 1 , wherein the oxide comprises:
5-14 wt % of an alkaline earth metal oxide;
35-70 wt % of a rare earth metal oxide;
6-20 wt % of Y 2 O 3 ; and
a balance of ZrO 2 .
3 . The thermal spray material feedstock of claim 1 , wherein the oxide comprises:
5-9 wt % of an alkaline earth metal oxide;
41-63 wt % of a rare earth metal oxide;
15-24 wt % of Y 2 O 3 ; and
a balance of ZrO 2 .
4 . The thermal spray material feedstock of claim 3 , wherein the alkaline earth metal oxide is MgO.
5 . The thermal spray material feedstock of claim 3 , wherein the rare earth metal oxide comprises at least one of 1-2 wt % La 2 O 3 and 24-38 wt % Gd 2 O 3 .
6 . The thermal spray material feedstock of claim 3 , comprising a total costly oxide content comprising at least one of Y 2 O 3 and Gd 2 O 3 that is 55 wt. % or lower.
7 . The thermal spray material feedstock of claim 2 , wherein the alkaline earth metal oxide is at least one of CaCO 3 , CaO, or MgO.
8 . The thermal spray material feedstock of claim 2 , wherein the rare earth metal oxide is at least one of Yb 2 O 3 , Gd 2 O, or Sm 2 O 3 .
9 . The thermal spray material feedstock of claim 1 , comprising lower than 2 wt % of La 2 O 3 or other sources of La.
10 . The thermal spray material feedstock of claim 1 , comprising a total costly oxide content comprising at least one of Hf-oxide, Ta-oxide, Dy-oxide, Nb-oxide, Nd-oxide, Gd-oxide, and Y-oxide that is 55 wt. % or lower.
11 . A method for manufacturing an abradable sealing coating comprising:
plasma spraying the thermal spray material feedstock of claim 1 onto a turbine blade or a part of a jet engine,
wherein the thermal spray material feedstock comprises an oxide that interfaces with the turbine blade or the part of the jet engine.
12 . An abradable sealant coating comprising the HEO of claim 1 .
13 . The abradable sealant coating of claim 12 , wherein the HEO has a high configurational entropy that is greater than 1.5R.
14 . The abradable sealant coating of claim 12 , further comprising a thermal barrier coating base coat.
15 . The abradable sealant coating of claim 14 , wherein all oxides form a single phase solid solution.
16 . The abradable sealant coating of claim 14 , wherein multiple oxide phases are present.
17 . The abradable sealant coating of claim 14 , wherein the abradable sealant coating has a porosity of about 30-70% by cross-sectional area.
18 . The abradable sealant coating of claim 14 , wherein the abradable sealant coating comprises at least one fugitive phase.
19 . The abradable sealant coating of claim 18 , wherein the at least one fugitive phase comprises polyester, talc, and boron nitride.
20 . The abradable sealant coating of claim 12 , wherein the HEO is represented by general formula M x O y , wherein M is chosen from a group comprising at least 5 different oxide-forming metallic cations.
21 . The abradable sealant coating of claim 12 , wherein the HEO is represented by general formula M x O y wherein M is chosen from at least one member of Group II in the periodic table.
22 . The abradable sealant coating of claim 12 , wherein the HEO is represented by general formula M x O y wherein M is chosen from at least one lanthanide in the periodic table.
23 . The abradable sealant coating of claim 12 , wherein the HEO is represented by general formula M x O y , wherein M is chosen from at least one transition metal.
24 . The abradable sealant coating of claim 12 comprising 5 or more different oxide-forming metallic cations in an amount greater than 5 mol %.
25 . A turbine blade comprising the abradable sealant coating of claim 12 .
26 . A part of a jet engine comprising the abradable sealant coating of claim 12 .
27 . A high entropy oxide powder comprising:
5-14 wt % of at least one alkaline earth metal oxide comprising CaCO 3 , CaO, or MgO;
35-70 wt % of at least one rare earth metal oxide comprising Yb 2 O 3 , Gd 2 O, or Sm 2 O 3 ;
6-20 wt % Y 2 O 3 ; and
a balance of ZrO 2 ;
wherein the high entropy oxide powder has a high configurational entropy that is greater than 1.5R.
28 . A thermal spray material feedstock, comprising:
an oxide having calcia magnesia alumina silicate (CMAS) resistance,
wherein when the oxide is reacted at 1250° C. for 8 hours with a CMAS having a low melting temperature of 1110° C. to 1125° C., the oxide exhibits a CMAS penetration depth of 100 μm or less; and
wherein the oxide is a high entropy oxide powder having a high configurational entropy that is greater than 1.5R.
29 . The thermal spray material feedstock of claim 28 , wherein the high entropy oxide powder comprises,
5-14 wt % of at least one alkaline earth metal oxide comprising CaCO 3 , CaO, or MgO;
35-70 wt % of at least one rare earth metal oxide comprising Yb 2 O 3 , Gd 2 O, or Sm 2 O 3 ;
6-20 wt % Y 2 O 3 ; and
a balance of ZrO 2 .