Thermal barrier coatings for internal combustion engines

Patent metadata

Field	Value
Publication number	US-11519329-B2
Application number	US-202017014992-A
Country	US
Kind code	B2
Filing date	Sep 8, 2020
Priority date	Sep 6, 2019
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A thermal barrier coating for an internal combustion engine includes an insulating thermal spray coating, where a chosen material of the insulating thermal spray coating has a thermal conductivity lower than 2 W/mK in fully dense form and the chosen material includes a coefficient of thermal expansion within 5 ppm/K of a coefficient of thermal expansion of a material of a component of the internal combustion engine upon which the coating is placed.

First claim

What is claimed is:

1. A thermal barrier coating for an internal combustion engine, comprising:
an insulating thermal spray coating, wherein:
a chosen material of the insulating thermal spray coating has a thermal conductivity lower than 2 W/mK in fully dense form; and
the chosen material includes a coefficient of thermal expansion within 5 ppm/K of a coefficient of thermal expansion of a material of a component of the internal combustion engine upon which the coating is placed, wherein the insulating thermal spray coating comprises a material from the sodium zirconium phosphate (“NZP”) class of ceramics that have a single crystal coefficient of thermal expansion below 5 ppm/K.

2. The thermal barrier coating of claim 1 , wherein the insulating thermal spray coating comprises a perovskite material.

3. The thermal barrier coating of claim 2 , wherein the perovskite material is of the A 2 B 2 O 9 category, where A and B are cations.

4. The thermal barrier coating of claim 1 , wherein the insulating thermal spray coating comprises lanthanum molybdate (La 2 Mo 2 O 9 ).

5. The thermal barrier coating of claim 1 , wherein the insulating thermal spray coating comprises lanthanum molybdate (La 2 Mo 2 O 9 ) with at least one dopant, wherein the dopant is one of Bi, Ni, Rb, Y, Gd, Nd, Ba, Sr, Ca.

6. The thermal barrier coating of claim 1 , wherein the insulating thermal spray coating comprises gadolinium zirconate (Gd 2 Zr 2 O 7 ).

7. The thermal barrier coating of claim 1 , wherein the insulating thermal spray coating comprises lanthanum strontium cobalt ferrites, of the type La y Sr 1-y Co 1-x Fe x O 3 oxides.

8. The thermal barrier coating of claim 7 , wherein the x=0.4.

9. The thermal barrier coating of claim 1 , wherein the material from the sodium zirconium phosphate (“NZP”) class of ceramics is one of Sr 0.5 Hf 2 (PO 4 ) 3 , Sr 0.5 Zr 2 (PO 4 ) 3 , Ca 0.25 Sr 0.25 Zr 2 (PO 4 ) 3 , CsHf 2 (PO 4 ) 3 , Ca 0.25 Sr 0.25 Zr 2 (PO 4 ) 3 , Cs 1.3 Gd 0.3 Zr 1.7 (PO 4 ) 3 .

10. The thermal barrier coating of claim 1 , wherein the insulating thermal spray coating comprises calcium hexa-aluminate.

11. The thermal barrier coating of claim 1 , wherein the component is steel.

12. The thermal barrier coating of claim 11 , wherein the material from the sodium zirconium phosphate (“NZP”) class of ceramics is one of Sr 0.5 Hf 2 (PO 4 ) 3 , Sr 0.5 Zr 2 (PO 4 ) 3 , Ca 0.25 Sr 0.25 Zr 2 (PO 4 ) 3 , CsHf 2 (PO 4 ) 3 , Ca 0.25 Sr 0.25 Zr 2 (PO 4 ) 3 , Cs 1.3 Gd 0.3 Zr 1.7 (PO 4 ) 3 .

13. The thermal barrier coating of claim 1 , further comprising surface treatments through application of a top layer to enhance smoothness or enhance erosion resistance or reduce surface porosity.

14. The thermal barrier coating of claim 1 , further comprising a material to absorb thermal radiation at or near a surface of the insulating thermal spray coating.

15. The thermal barrier coating of claim 14 , wherein the material to absorb thermal radiation is one of Phosphor bonded Al 2 O 3 , Phosphor bonded Cr or Fe doped Al 2 O 3 , Phosphor bonded SiO 2 , Phosphor bonded Cr or Fe doped SiO 2 , Phosphor bonded ZrO 2 , Phosphor bonded Cr or Fe doped ZrO 2 , or calcium magnesium aluminosilicate glass.

16. The thermal barrier coating of claim 14 , wherein the material further comprises silicon carbide or silicon nitride.

17. The thermal barrier coating of claim 1 , wherein the component is one of a piston crown, a combustion chamber, a valve face, an exhaust port, or an exhaust manifold section.

18. A method for forming a thermal barrier coating, the method comprising:
applying an insulating thermal spray coating, wherein:
a chosen material of the insulating thermal spray coating has a thermal conductivity lower than 2 W/mK in fully dense form; and
the chosen material includes a coefficient of thermal expansion within 5 ppm/K of a coefficient of thermal expansion of a material of a component of the internal combustion engine upon which the coating is placed, wherein the insulating thermal spray coating comprises a material from the sodium zirconium phosphate (“NZP”) class of ceramics that have a single crystal coefficient of thermal expansion below 5 ppm/K.

19. The method of claim 18 , further comprising polishing the insulating thermal spray coating.

20. A thermal barrier coating for an internal combustion engine, comprising:
an insulating thermal spray coating, wherein:
a chosen material of the insulating thermal spray coating has a thermal conductivity lower than 2 W/mK in fully dense form; and
the chosen material includes a coefficient of thermal expansion within 5 ppm/K of a coefficient of thermal expansion of a material of a component of the internal combustion engine upon which the coating is placed, wherein the component is steel and the insulating thermal spray coating comprises a material from the sodium zirconium phosphate (“NZP”) class of ceramics that have a single crystal coefficient of thermal expansion below 5 ppm/K.

Assignees

• Univ Connecticut

Inventors

• Jordan Eric
• Jiang Chen
• Kumar Rishi
• Nair Balakrishnan

Classifications

• F05C2251/048

  Heat transfer · CPC title

• F05C2251/042

  Expansivity · CPC title

• F02F3/12

  on piston heads · CPC title

• F05C2253/12

  Coating · CPC title

• F01L3/04

  Coated valve members or valve-seats · CPC title