Abrasive tip coating
A blade has an airfoil having a tip. The blade has a metallic substrate and a coating system atop the substrate at the tip. The coating system has: a first layer of at least 99.0% weight nickel; an abrasive layer having a matrix and an abrasive at least partially embedded in the matrix; and a second layer between the first layer and the matrix. The second layer is tougher or more ductile than at least one of the first layer and the matrix.
1. A blade having an airfoil having a tip, the blade comprising:
a nickel alloy substrate; and
a coating system atop the substrate at the tip and comprising:
a first layer comprising by weight at least 99.0% nickel;
an abrasive layer, comprising:
a matrix; and
an abrasive at least partially embedded in the matrix; and
a copper or copper alloy second layer between the first layer and the matrix and tougher or more ductile than at least one of the first layer and the matrix.
2. The blade of claim 1 wherein:
the second layer has higher fracture toughness than the at least one of the first layer and the matrix.
3. The blade of claim 1 wherein:
the second layer is more ductile than the at least one of the first layer and the matrix.
4. The blade of claim 1 wherein:
the second layer is tougher than the matrix.
5. The blade of claim 1 wherein:
the second layer is tougher than the first layer.
6. The blade of claim 1 wherein:
the first layer is 3.0 micrometers to 10.0 micrometers thick.
7. The blade of claim 1 wherein:
the second layer is 2.0 micrometers to 25.0 micrometers thick.
8. The blade of claim 1 wherein:
the abrasive is selected from the group consisting of:
cubic boron nitride;
silicon carbide;
aluminum oxide;
titanium boride; and
combinations thereof; and
the matrix comprises at least 99.0% nickel by weight.
9. A method for manufacturing the blade of claim 1 , the method comprising:
applying the first layer by Wood's nickel strike;
applying the second layer by electrodeposition of at least 99.0 weight percent pure copper;
applying the abrasive with a tack portion of the matrix; and
applying a further portion of the matrix without further abrasive.
10. A blade having an airfoil having a tip, the blade comprising:
a metallic substrate; and
a coating system atop the substrate at the tip and comprising:
a nickel-based first layer;
an abrasive layer, comprising:
a matrix; and
an abrasive at least partially embedded in the matrix; and
a second layer between the first layer and the matrix and comprising by weight at least 80% nickel and 1.0% to 10.0% cobalt, the first layer having at least 5.0 weight percent more cobalt than the second layer.
11. The blade of claim 10 wherein:
the second layer comprises, by weight, at least 95% nickel and 1.0% to 2.0% cobalt.
12. The blade of claim 11 wherein:
the second layer comprises, by weight, no more than 1.0% elements other than said nickel and cobalt.
13. The blade of claim 10 wherein the first layer comprises:
14 to 35 weight percent Co.
14. The blade of claim 10 wherein:
the first layer is 0.5 micrometers to 13.0 micrometers thick; and
the second layer is 2.0 micrometers to 25.0 micrometers thick.
15. The blade of claim 10 wherein:
the metallic substrate is a nickel alloy substrate.
16. A method for manufacturing the blade of claim 10 , the method comprising:
applying the first layer by Wood's nickel strike;
applying the second layer by sulfamate nickel plating;
applying the abrasive with a tack portion of the matrix; and
applying a further portion of the matrix without further abrasive.
17. The method of claim 16 wherein:
the applying the abrasive with the tack portion of the matrix is by sulfamate nickel plating; and
the applying the further portion of the matrix without further abrasive is by sulfamate nickel plating.
18. The method of claim 17 wherein:
the second layer is tougher than the tack portion.
19. A blade having an airfoil having a tip, the blade comprising:
a nickel alloy substrate; and
a coating system atop the substrate at the tip and comprising:
a first layer comprising by weight at least 99.0% nickel;
an abrasive layer, comprising:
a matrix; and
an abrasive at least partially embedded in the matrix; and
an aluminum-manganese alloy second layer between the first layer and the matrix and tougher or more ductile than at least one of the first layer and the matrix.
20. The blade of claim 19 wherein the second layer comprises:
4.0 to 14.0 atomic percent Mn.
21. The blade of claim 19 wherein the second layer is:
Al-7.8Mn alloy.
22. The blade of claim 19 wherein:
the first layer is 0.5 micrometers to 13.0 micrometers thick; and
the second layer is 2.0 micrometers to 25.0 micrometers thick.
23. A method for manufacturing the blade of claim 19 , the method comprising:
applying the first layer by Wood's nickel strike;
applying the second layer by electrodeposition of said aluminum-manganese alloy;
applying the abrasive with a tack portion of the matrix; and
applying a further portion of the matrix without further abrasive.
24. The method of claim 23 wherein:
the applying the abrasive with the tack portion of the matrix is by sulfamate nickel plating; and
the applying the further portion of the matrix without further abrasive is by sulfamate nickel plating.
25. The method of claim 23 wherein the electrodeposition is:
electrodeposition of Al-7.8Mn alloy.